9-1267
United States Department of the Interior
Geological Survey
Mineral Resources of the Glacier Bay National Monument
Wilderness Study Area, Alaska
by
David A. Brew, Bruce R. Johnson, Donald Grybeck, Andrew Griscom, and
David F. Barnes, U.S. Geological Survey
and by
Arthur L. Kimball, Jan C. Still, and Jeanne L. Rataj,
U.S. Bureau of Mines
n
Open-file Report 78-494
1978
This report is preliminary and has
not been edited or reviewed for
conformity with Geological Survey
standards and 9-1267
STUDIES RELATED TO WILDERNESS STUDY AREAS
In accordance with the provisions of the Wilderness Act 3 (Public Law 88-577, September 3, 1964) and the Joint Conference
4 Report on Senate Bill 4, 88th Congress, the U.S. Geological
iSurvey and U.S. Bureau of Mines have been conducting mineral I 6 \ jsurveys of wilderness and primitive areas. Studies and reports i ,of all primitive areas have been completed. Areas officially i idesignated as "wilderness", "wild", or "canoe" when the Act was
9 :! passed were incorporated into the National Wilderness 10_ i preservation System, and some of them are presently being i n i jstudied. The Act also provided for suitability studies of areas i 12 Junderi consideration for wilderness designation. Mineral surveys
13 i s constitute one aspect of the suitability studies. This report u I Jdiscusses the results of a mineral survey of national park 15 i' !system lands in the Glacier Bay National Monument study area,
jAlaska, that are being considered for wilderness designation. T7 ; jThe area studied is between tidewater and the International
'3 ' Boundary in the Pacific Border Ranges about 160 km (100 mi)
west of Juneau in southeastern Alaska. ji 20 :
11 9-1267
1 !i Contents ji 2
3 j Page 4 Chapter A. Summary and introduction A-l i i 5 | Summary A-l j i i i Introduction £-19 i i 7 Access, use, and general character A-20
a | Previous studies A-27 o j Acknowledgments A-2J9
ic .Chapter B. Geology, geophysics, and geochemistry - - B-l i! " Geology, by David A. Brew - .87!
, 2 I Introduction B-l; j Present investigations B-l1 13 i Geologic setting B-4! i 14 | Lituya province B-9J i is | Fairweather province ~ B-12
16 | Geikie province - B-15
:7 | Chilkat province B-rl7
13 ; Muir province B-20
19 Interpretation of the aeromagnetic map of Glacier i :- Bay National Monument, Alaska by Andrew Griscom B-22
r, Aeromagnetic data and interpretation methods B-22 i 22 i Magnetic properties of rocks B-29
'< * | General interpretation of the aeromagnetic map- B-32 24 i Intrusive rocks B-34
111 9-1267
,Chapter B. Geology, geophysics and geochemistry continued ! 1 ; I Interpretation of the aeromagnetic map of Glacier i
Bay National Monument continued j i i Intrusive rocks continued Page 5 Layered gabbro complexes B 34
Foliated granitic rocks B-38
Unfoliated felsic granitic rocks B-43
Layered rocks B-44
Hornblende schist and gneiss B-44
10 Sedimentary and metasedimentary rocks B-45 Paleozoic volcanic rocks B-46
Faults B-48
Major magnetic boundary B-49
Interpretation of the gravity and ice-thickness data
by David F. Barnes, R. L. Morin, and R. D. Watts B-51
16 Gravity data B-52
Dens ity data B-5 7
Description and interpretation of the gravity
Ice- thickness measurements B-70
Geochemistry, by Bruce R. Johnson and Donald Grybeck- 5"^^ 22 Introduction B-76
Analytical support B-79
Statistical treatment of data B-83
25- !
IV 9-1257
1 Chapter B. Geology, geophysics, and geochemistry continued
2 Geochemistry continued
3 j! Statistical treatment of data continued ; i Stream sediments - B-83 ] ; 5- i Rocks B-121 j 6 | Interpretation of data B-177
7 i Crustal abundances B-177
8 I Rock geochemical anomalies B-179 i i i Stream sediment anomalies B-184 i J°- | Uranium analyses B-192
11 | Correlation studies B-193 i i 12 JGhapter C. Mineral resources, by Arthur L. Kimball, Jan C. Still, I 13 | and Jeanne L. Rataj - - C-1
14 j Introduction C-1 i l3 , Present studies C-1
'* i Sampling C-3 i i7 j Sample types C-3
13 ; Sample tables and analyses C-4
? . Measurement C-5
" :~~ ; Production C-6
21 | Mining claims c~7
Areas favorable for mineral deposits C-9 23 J Commodity discussion C-14
24 Organization C-17
v 9-1267
Chapter C. Mineral resources continued i Lituya province C-28
Pacific beach sands C-28 i Introduction and summary C-28
History and production C-31
Mining claims C-34
Geologic setting C-35 I Bedrock C-35
Unconsolidated deposits C-35 Provenance of heavy minerals C-42 <__Concen.tra.tion_ of heavy minerals C-45 Sampling method C-46
' Sample preparation and analysis C-49
13 Sample results C-53
Resource calculations C-86 i 15 Inferred resources C-86
Hypothetical resources C-91
Remainder of the province C-91
Fairweather province C-95
Introduction C-95
Crillon-La Perouse stock and vicinity C-96
Brady Glacier nickel-copper deposit C-96 i Introduction . C-96
Geology and mineral deposits C-97
VI ?-1267
1 Chapter G. Mineral resources continued
2 i Fairweather province continued Page Crillon-La Perouse stock and vicinity continued
Brady Glacier nickel-copper deposit continued Tonnage C-99
Other mineralized areas near the Crillon-La Perouse stock C-101
North wall of the South Crillon Glacier C-101
South wall of the North Crillon Glacier C-106
Additional mineralized occurrences- C-108 Mount Fairweather stock and vicinity - - C-108
Astrolabe-De Langle stock C-119
De Langle'Mountain magnetite prospect- C-119 Other mineralization in vicinity -C-122
Remainder of the prpvince C-123
North Geikie sub-province -C-127
Margerie Glacier favorable area C-127
Orange Point zinc-copper deposit C-129
Introduction C-129
Geology C-130
VI1 9-12&7
Chapter C. Mineral resources continued
North Geikie sub-province continued
Margerie Glacier favorable area continued
Orange Point zinc-copper deposit continued i ! Description of mineralized zones ! resources C-135
Limits of this investigation and work necessary to further delineate this depos i t - c^!4 6
Summary C-146
Other potential volcanogenic sulfide ' showings C -14 7
3,087 nunatak 0^147 i South side of Johns Hopkins Inlet C-147 i Margerie Glacier porphyry-copper deposit C-149 Introduction C-149
Geo lo gy - C 15 0 deposit Resources of the Margerie Glacier- C-160 Potential of the
Margerie Glacier deposit vicinity C-161 Tarr Inlet knob prospect and vicinity C-162
North side of Johns Hopkins Inlet gold
22 anomaly C-168 Johns Hopkins_J.nlet_moj.ybdenum anomalous area C 168 Other anomalous areas in the Margerie 24 Glacier favorable area C-169
25
Vlll 9-1267
Chapter C. Mineral resources continued
North Geikie province continued Page i 4 ; Rendu Glacier favorable area C-169 ! :- Massive chalcopyrite deposit C-180
1 Mineralization in the vicinity of the i
massive chalcopyrite deposit C-183
3 Other mineralization in the Rendu Glacier ( ; favorable area C-186
:°~ \ Fixed-rope ice gully skarn showing C-186
, Crampon ice gully mineralized area C-186 12 i Remainder of North Geikie sub-province C-187 i j ! ' 3 : Little Jennie and the Silver Dick !i 14 | . patented claims C-187
J~ Other mineralized zones and prospects in the ce<**9\*de-(~ \ 14 A of North Geikie sub-province C-188
'' Middle Geikie sub-province C-193
3 Introduction C-193
Reid Inlet gold area C-195
^- Introduction C-195
2' LeRoy mine C-199 i 22 : Rainbow mine : C-206
--> Incas mine - . . . . . ,_C-215
24 ; Monarch #1 and #2 mines .C-217
IX 9-1267
Chapter C. Mineral resources continued j i Middle Geikie sub-province -continued Page i Reid Inlet gold area-ffontinued Sentinal mine CH221
Highland Chief (Joe's Dream) prospect C-222
Rambler (Challenger) prospect C-230 Galena prospect C-233
Sunrise prospect C-233
A. F. Parker prospect C-234
10 Hop along prospect C-236
Whirlaway prospect C-237
Mt. Parker area C-:237
13 Russell Island gold prospect C-238
Ptarmigan Creek basin C-242
C on c lus ion C - 2 4 5
Remainder of the province C-246
South Geikie sub-province C-252
Threesome Mountain molybdenum-tungsten deposit- C-253 Dundas Bay tungsten prospect C-257
Gold placer south of Wood Lake C-264 Other occurrences or prospects in South Geikie sub-province--- - C-264 Muir Province C-272 22 Muir Inlet favorable area C-272
The Nunatak molybdenum deposit C-274 Introduction C-274 9-1267
Chapter C. Mineral resources continued
Muir province continued ] ! < \ Muir Inlet favorable area continued . Page
! The Nunatak molybdenum deposit continued Geology C-275
Molybdenum ore metal mineralization C-276 Identified resources C-287
Identified resources summary C-293 i i Mineralization outside the molybdenum i ID- I . area > " ' " « ' !' '»> > " ' '! > " > n«n- ) i**Miiiiiimm ,* ** \^~L£J3
i Resource potential C-295 i i Bruce Hills copper-molybdenum prospect C-295 I i { Wachusett Inlet copper-molybdenum prospect- C-307 i Idaho Ridge prospect C-310
i Minnesota Ridge prospect C-310 i , Other prospects or mineralized areas C-313 Remainder of Muir province C-319
Mt. Brack zinc-copper prospect C-319
: Other prospects or mineralized zones in the , remainder of Muir province C-320
North Chilkat sub-province C-327
Miller Peak-White Glacier area C-327
White Glacier mineralized areas C-328
Sandy Cove gold-copper prospect C-334
XI Chapter C. Mineral deposits continued
North Chilkat sub-province-continued
Miller Peak-White Glacier area-continued Miller Peak copper prospect C-342
"~ The remainder of North Chilkat sub-province C-344 Mt. Merriam area C-345
Other mineral occurrences in the remainder p of North Chilkat sub-province C-347 9 ; South Chilkat sub-province C-352
Alaska Chief copper deposit C-353 p i Dundas Bay altered zone C 354
Exray copper prospect C-358
Valley of Tears placer C-363
; Other prospects in South Chilkat sub-province- C-364 Miscellaneous commodities C-370
. Geothermal resources _ C-370
'Oil, gas, and coal C-373
Nuclear fuels C-374 Industrial minerals C-375
Chapter D. Evaluation of mineral resources D-1
Introduction - D-1
2"1 ' f Identified resources D-fe
Xll 1 I Chapter D. Evaluation of mineral resources continued
2 ! Identified resources continued | 3 i Lituya province
a i Pacific beach placer deposits D-6 - . Fairweather province D-8
! Brady Glacier nickel-copper deposit .D-8 / Geikie province D-10
3 : Margerie Glacier copper deposit D-10
9 Orange Point zinc-copper deposit D-12 'o- Massive chalcopyrite deposit D-14
11 | Reid Inlet gold deposits D-15
12 i Alaska Chief copper deposit D-16
13 I Muir province . D-17
4 I The Nunatak molybdenum deposit D-17
' 5 : Hypothetical and speculative resources D-20 '6 j Introduction D-20
'' Lituya province D 23
13 Pacific beach placer favorable area D-23 " Fairweather province D-24 : - Crillon-La Perouse favorable area D-24
:: ; Mt. Fairweather favorable area D-28
22 ! Geikie province D-29 i " Margerie Glacier favorable area D-29
24 ; Rendu Glacier favorable area D-34
o^ _ ,' i______,______.______
xiii 9-1267
Chapter D. Evaluation of mineral resources continued
Hypothetical and speculative resources continued Reid Inlet favorable area D-35
I Alaska Chief favorable area D 36
i Muir province D-37
! Muir Inlet favorable area D-37
f Casement Glacier favorable area D 39 1 Chilkat province D-40 j i White Glacier favorable area Dr-40
10 | Other areas with geochemical and(or) geophysical i anomalies - D-41
; Other commodities and areas D-43
i Conclusion D-44 j ; ! Chapter E. References - ^-1
16
21
22
XIV 1 { Illustrations
2 'Plate la- Generalized reconnaissance geologic map of Glacier Bay i 3 ! National Monument, Alaska
4 i lb. Aeromagnetic map of Glacier Bay National Monument, Alaska ] -~ : 2- Geochemical sample locality map, Glacier Bay National
, i | Monument, Alaska
7 : 3. Map of Glacier Bay National Monument Wilderness Study
I Area, Alaska, showing location of detailed figures,
i mining claim density, selected deposits, and prospects
°~ j and locations of other mineral occurrences
11 ; 4. The Nunatak molybdenum deposit, geologic map and
12 i sections
~ .Figure A-l. Map of Glacier Bay National Monument Wilderness study
14 i area, Alaska, showing ..significant mineral deposits,
!5~~ outlines of areas favorable for mineral deposits, and ! areas with important unchecked geochemical and (or) 'J ; geophysical anomalies
A-2. Index map showing Glacier Bay National Monument, Alaska,
and geologic provinces within the monument A-21
A-3. Photograph looking northeast across Lituya Bay at the
crest of the Fairweather Range Mount Fairweather on
the left and Lituya Mountain on the right A-23
A-4. Photograph looking north up Muir Inlet from near Mount
Wright; Nunatak molybdenum deposit is on isolated dark peak in right middleground A-24
xv 9-1267
Illustrations continued Page
A-5. Oblique aerial photograph looking southwest at the
southwestern part of the Brady Glacier Icefield; Brady
Glacier nickel-copper deposit is exposed on nunatak ! near center of photograph r-A-26
B-l. Interpretation of the aeromagnetic map of Glacier Bay National Monument, Alaska B-25
B-2. Cross-sections of calculated models simulating observed
magnetic profiles. Profile A-A' crosses the gabbro-
complex of Astrolabe Peninsula. Profile B-B'
simulates the magnetic profile across a mountain on
the east side of Glacier Bay north of Beartrack Cove. Location shown on figure B-l. B-36
B-3. Cross-sections of calculated models simulating
observed magnetic profiles across the major magnetic
boundary. Profile C-C' is across the south end of
of the boundary. Profile D-D' is across the central
part of the boundary. Location shown on figure B-l B-41
B-4. Simple Bouguer anomaly map of Glacier Bay National Monument, and vicinity, Alaska B-54
B-5. Bar graph of hand-specimen rock densities B-58
B-6. Brady Glacier ice-thickness measurements B-73
xvi 9-1267
Illustrations continued
B-7. Histograms of the distribution of selected metals in stream-sediment samples B-86
B-8. Histograms of the distribution of silver in each rock- ! i geochemical unit B-125 i B-9. Histograms of the distribution of cobalt in each rock-geochemical- unit B-126
B-LO. Histograms of the distribution of chromium in each rock-geochemical unit - B-127
B-ll. Histograms of the distribution of molybdenum in each : rock-geochemical unit B-128 i 12 i B-12. Histograms of the distribution of nickel in each
13 rock-geochemical unit B-129
B-13. Histograms of the distribution of lead in each l rock-geochemical unit B-130 i B-14. Histograms of the distribution of tin in each rock-geochemical unit B-131
B-15. Histograms of the distribution of tungsten in each rock-geochemical unit B-132
B-16. Histograms of the distribution of gold in each rock-geochemical unit B-133
xvn 9-1257
Illustrations continued
B-17- Histograms of the distribution of mercury in each i i rock-geochemical unit B-134 I B-18- Histograms of the distribution of copper in each i rock-geochemical unit B-135
B-19- Histograms of the distribution of zinc in each
rock-geochemical unit B-136
B-20. Map of Glacier Bay National Monument showing major j i geographic features, intrusive bodies, and areas ! i containing anomalous rock geochemical samples B 180
B-21. Map of Glacier Bay National Monument showing major i
geographic features, intrusive bodies, and areas |
containing anomalous stream-sediment samples B-180 C-l. This figure number not used.
!
C-2. Map showing the distribution of selected deposits and
prospects C-18
C-3. Index map for Pacific beach sands, showing location
of sample lines C-29
C-4. Sea Otter Creek to Fairweather Glacier, sample line locations C-37
xviii 9-1267
Illustrations continued Page j C-5. "Fairweather River" to Lituya Bay, sample line I
locations C-38
C-6. Lituya Bay to La Perouse Glacier, sample line I locations C-39
C-7. La Perouse Glacier to Boussole Bay, sample line locations C-40
C-8. Flowchart for physical and chemical analyses of beach sand samples C-50
C-9. Profile of beach at Sea Otter Creek near triangulation !
station "Fair C", sample locations, line no. 1 C-57
C-1Q. Profile of beach at Sea Otter Creek near triangulation
station "Fair B", sample locations, line no. 2. C-57
C-ll. Profile of beach north of the "Fairweather River" ' sample locations, line no. 3- C-60
C-12. Profile of beach one-half mile south of the "Fair-
weather River", sample locations, line no. 4 C-60
C-13. Profile of beach two miles south of the "Fairweather River", sample locations, line no. 5 C-61
C-14. Profile of beach at Justice Creek, sample locations, line no. 6 C-61
xix 9-3267
Illustrations continued page
C-15. Profile of beach two miles south of Justice Creek, sample locations, line no. 7 C-64
C-16. Profile of beach at the mouth of Echo Creek, ! 5 sample locations, line no. 8 C-64
C-17. Profile of beach one-fourth mile south of Echo Creek, sample locations, line no. 9 ' C-68
C-18. Prospect trench one-fourth mile south of Echo Creek, i i sample line nos. 10-12, sample locations C-68
C-19. Profile of beach three miles south of Harbor Point, i i sample locations, line no. 13 C-70
C-20. Profile of beach three and one-half miles south of :
Harbor Point, sample locations, line no. 14 - C-70
C-21. Profile of beach at Topsy Creek, sample locations, ; 15 ' line no. 15 - C-72
C-22. Two miles south of Topsy Creek, sample locations, line no. 16 - . - - C 72
C-23. Profile of beach ncrth of Dagelet River, sample locations, line no. 17 C-74
C-24. Profile of beach one mile north of La Perouse Glacier, sample locations, line no. 18 C-74
C-25. Profile of beach one and one-half miles south of
La Perouse Glacier, sample locations, line no. 19 -
xx 9-1267
Illustrations continued Page i C-26» Three and one-half miles south of La Perouse Glacier, j ! sample locations, line nos. 20-21 - C-77 i C-27. Kaknau Creek, sample locations, line no. 22 C-'79
C-28. Mouth of "Palma River", sample locations, line no. 23- C-79
C-29. Boussole Bay, sample locations, line nos. 24-26 - C-81
C-30. Location of resource blocks for Pacific beach sands - C-90
C-31. This figure number not used ". j
C-32. North and South Crillon Glaciers mineralized areas, sample locations - C-103 i C-33. North side of the South Crillon Glacier, sample : i locations- C-104
C-34. Mount Fairweather layered mafic stock, sample locations C-114
C-35. Astrolabe-De Langle stock, De Langle Mountain magnetic prospect, sample locations C-121
C-36. Orange Point zinc-copper deposit, sample locations C-131
C-37. Oblique aerial photograph of the Orange Point zinc-
copper deposit, showing the southwest side of
Hill no. 1 and no. 2 mineralized zones and sample locations C-136
C-38. Johns Hopkins Inlet, showing molybdenum anomaly area,
gold anomaly location and location of sulfides in volcanic rocks C-148
C-39. Index map for Margerie Glacier and Tarr Inlet knob area c-151
xxi Illustrations continued Page I C-40. Margerie Glacier porphyry-copper deposit, sample ! locations C-15 3 | G-41. Tarr Inlet knob prospect and vicinity, sample locations C-164 i C-42. Rendu Glacier favorable area, sample locations C-177
C-43. Oblique aerial photograph of the west side of the Rendu i Glacier favorable area, showing copper-stained zones
and sample locations C-179
G-44. Massive chalcopyrite deposit and vicinity, sample :
locations and magnetometer survey results C-184
G-45. Reid Inlet gold . area, mine and prospect locations- C-196
C-46. LeRoy mine, west workings, sample locations C-200
C-47. LeRoy mine,, east workings, sample locations C-201
C-48. Rainbow mine, sample locations C-214
C-49- Incas mine, sample locations C-216
C-50. Monarch no. 1 mine, sample locations C-219
G-51- Monarch no. 2 mine, sample locations C-220
C-52. Highland Chief prospect (Joe's Dream) sample locations- C-224
C-53. Cross-section of pit no. 1, Highland Chief prospect
(Joe's Dream), sample locations C-22"?
C-54. A. F. Parker prospect, sample locations C-235
C-55. Russell Island prospect, sample locations C-239
C-56. Threesome Mountain molybdenum-tungsten prospect, sample locations C-254
xxn 9-1267
Illustrations continued Page* i C-57. Head of the east arm of Dundas Bay, stream sediment
sample locations C-258
C-58. Dundas Bay tungsten prospect, sample locations C-259
C-59. The Nunatak molybdenum deposit, Nunatak fault zone,
sample locations C-285
C-60. The Nunatak molybdenum deposit, area of conspicuous
molybdenum, sample locations C-289
C-61. Bruce Hills location map C-296
C-62. Central Bruce Hills, southside, sample line crossing top of southwest-trending fault gully C-299
C-63. Central Bruce Hills, northside, copper-molybdenum showing, sample locations C-305
* ( C-64. Wachusett Inlet copper-molybdenum prospect, sample loca t ions - C-308
C-65. Idaho Ridge prospect, sample locations C-311
C-66. Minnesota Ridge prospect, sample locations C-314
C-67. Mt. Brack zinc-copper prospect, sample locations C-321
C-68. Mt. Brack mineralized zone, sample locations C-322
C-69- White Glacier zinc-copper prospect, mineralized areas
and sample locations C-329
C-70. White Glacier zinc-copper prospect, area no. 2 C-332
C-71. Sandy Cove gold-copper prospect, adit sample locations- C-335
XXlll Illustrations continued
C-72. Miller Peak copper prospect, sample locations. Also
shows the location of Sandy Cove adit 0336 C-73. Dundas Bay altered zone, sample locations C-356
C-74. Excursion Inlet, area investigated and location of prospect pits C-360
C-75. Exray prospect, workings and sample locations C-361
D-l. Classification of mineral resources and glossary of
mineral resource terms used by the U.S. Bureau of
Mines and the U.S. Geological Survey (1976) D-2.
xx iv 9-1267
Tables Page
3 Table A-l. Important mineral deposits and favorable
areas, Glacier Bay National Monument t ;- ' wilderness Study area, Alaska A-6
3 B-l. Magnetic properties of rocks from Glacier Bay National 9 Monument, Alaska B-31
]0~ B-2. U.S. Geological Survey 1976 ice-thickness measurements
!1 in Glacier Bay National Monument, Alaska B-71
12 ; B-3. Conversion between parts per million (ppm), percent (%),
3 and ounces per ton (oz/ton) B-82
u , B-4. Anomalous levels for selected metals in stream-sediments '~ :~ as used on plate 2 and figure B-7 B-85
s B-5. Anomalous and distinctly anomalous stream-sediment
samples collected by the Geological Survey B-89
;3 B-6. Rock units from plate 1 contained in rock geochemical :c units - B-l22
;: ~ B-7. Anomalous levels in parts per million for selected
; ' metals in bedrock geochemical samples as used on 22 plate 2 and figures B-8 to B-19 B-124
23 B-8. Anomalous bedrock geochemical samples collected by the :- Geological Survey B-137
xxv 9-1257
Tables continued Page i B-9. Comparison of average crustal abundances of selected
elements with approximate means of rock geochemical j
units, in parts per million 8-178
B-10. Results of uranium, analyses of selected Geological Survey samples B-194
B-ll. Correlation groups from geochemical analyses of rocks
and stream-sediment samples B-195
C-l. Important mineral deposits and favorable areas in Glacier
Bay National Monument wilderness study area C-12
C-2. National importance of commodities found in |
Glacier Bay National Monument C-l5
C-3. Locality list of deposits, Glacier Bay National Monuments-21
C-4. Pacific beach sands, petrographic examinations, heavy mineral constituents of select samples C-43
C-5. Assay data, Pacific beach sands, chemical and semi-
quantitative spectrographic analyses of ilmenite concentrates C-5 4
C-6. Assay data, Sea Otter Creek near triangulation station "Fair C", line no. 1 C-58
C-7. Assay data, Sea Otter Creek near triangulation station
"Fair B", line no. 2 c~59
C-8. Assay data, "Fairweather River" and vicinity,
line nos. 3, 4,. and 5 C~62
XXVI Tables continued Page
C-9« Assay data, Justice Creek, line no. 6 C-63 i C-10. Assay data, two miles south of Justice Creek, line no. 7C-65
C-ll. Assay data, mouth of Echo Creek, line no. 8 C-66
C-12. Assay data, one-fourth mile south of Echo Creek and
prospect trench, line nos. 9, 10, 11, and 12 - C-69
C-13. Assay data, between Harbor Point and Steelhead Creek,
line nos. 13 and 14 C-71
C-14. Assay data, Topsy Creek, line no. 15 C-73
C-15. Assay data, two miles south of Topsy Creek, line no. 16
C-16. Assay data, Dagelet River, line no. 17 C-75
C-17. Assay data, one mile north of La Perouse Glacier,
line no. 18 C-76
C-18. Assay data, between La Perouse Glacier and Icy Point,
line nos. 19, 20 and 21 C-78
C-19. Assay data, Kaknau Creek, line no. 22 c~80
C-20. Assay data, mouth of the "Palma River", line no. 23 C~80
C-21. Assay data, Boussole Bay, line nos. 24, 25 and 26 C-82
C-22. Pacific beach sands, sample sections and weighted
average grade of commodities along the section,
showing the parameters used in the grade calculation- C-84
C-23. Pacific beach sands, inferred resource calculation C-8 7
C-24. Pacific beach sands, summary of the extent and value of the inferred resource blocks C-88
XXVI1 Tables continued
C-25. Lituya province, mineral occurrences not discussed in
text . C-9 3
C-26a. Assay data, north side of the South Crillon Glacier copper-nickel mineralization zone C-105
C-26b. Assay data, south wall of the North Crillon Glacier copper-nickel-platinum mineralized zone C-107
C-27. Fairweather province, Crillon-La Perouse
favorable area, mineral occurrences not : discussed in text- . C-109
C-28. Assay data, Mount Fairweather stock and vicinity-- C-116
C-29. Fairweather province, remainder of the province,
mineral occurrences not discussed in text C-124
C-30. Assay data, Orange Point deposit, main Hill #2
mineralized zone .C-137
C-31. Assay data, Orange Point deposit, Hill #3 mineralized zone C-140
C-32. Assay data, Orange Point deposit, Hill #2, other
mineralization C-141
C-33- Assay data, Orange point deposit, Hill #1 mineralized zones C-142
C-34. Assay data, Margerie Glacier deposit, samples of disseminated mineralization C-154
XXVI11 9-1267
Tables continued
C-35. Assay data, Margerie Glacier deposit, samples of narrow ! i zone and vein-type mineralization C-156
C-36. Assay data, Tarr Inlet knob area C-165
C-37. North Geikie sub-province, Margerie Glacier
favorable area, mineral occurrences not discussed in text C-170
C-38. Assay data, Rendu Glacier favorable { i area -C 181
10 C-39. North Geikie sub-province, remainder of the sub- ',
province, mineral occurrences not discussed in text C-189
12 C-40. Assay data, LeRoy mine, Territorial Department of Mines C-207
C-41. Assay data, Reid Inlet gold area mines and prospects
(U.S. Geological Survey) r C-208
C-42. Assay data, LeRoy, Rainbow and Monarch mines ' (U.S. Bureau of Mines) C-:211
C-43. Assay data, Highland Chief (Joe's Dream) prospect- C-225
C-44. Assay data, Rambler (Challenger) prospect and A. F. Parker prospect C-232
C-45. Assay data, Russell Island prospect C-241
C-46. Middle Geikie sub-province, mineral occurrences not
discussed in text - C-247
C-47. Assay data, Threesome Mountain molybdenum-tungsten
p r ospec t C-25 5
XXIX 9-1267
Tables continued Pag|e
C-48. Assay data, Dundas Bay tungsten prospect C-261 ! | C-49. South Geikie sub-province, mineral occurrences not discussed in text C-266 i «;_ C-50. Assay data, the Nunatak molybdenum deposit, diamond drill hole samples C-280
C-51. Assay data, the Nunatak molybdenum deposit fault zone ! samples - . . . . .______C 286 j C-52. Assay data, the Nunatak molybdenum deposit, area of conspicuous molybdenite C-290
C-53. Summary information on the resources of the Nunatak molybdenum deposit C-294
C-54. Assay data, Bruce Hills C-300
C-55. Assay data, Wachusett Inlet copper-molybdenum Prospect- C-309 C-56. Assay data, Idaho Ridge prospect C-312
C-57. Assay data, Minnesota Ridge prospect C-315
C-58. Muir province, Muir Inlet favorable area, mineral occurrences not discussed in text C-316
C-59. Assay data, Mt. Brack zinc-copper prospect C-323
C-60. Muir province, remainder of the province, mineral occurrences not discussed in text C-325
22 C-61. Assay data, White Glacier prospects C-330
C-62. Assay data, Sandy Cove gold-copper prospect C-338 C-63. Assay data, Miller Peak copper prospect C-343
xxx 9-?26"
Tables continued Page i G-64. North Chilkat sub-province, mineral occurrences not ' I discussed in text C-348
C-65. Assay data, Dundas Bay altered zone C-!357 | C-66- Assay data, Exray prospect C-362
C-67- South Chilkat sub-province, mineral occurrences not discussed in text C-365
C-68. Analysis of water from Icy Point hot springs, i i ! Glacier Bay National Monument, Alaska C-372
xxxi Studies related to wilderness National Monuments
Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska Chapter A Summary and introduction
Summary The Wilderness Study Area includes all of Glacier Bay National Monument, an area of about 1,140,000 hectares (4,400 square miles or 2,817,000 acres) in the Pacific Border Ranges physiographic province centered about 160 km (100 miles) west-northwest of Juneau, Alaska (fig. A-l).
Figure A-l near here
Mineral resource considerations may be a critical part of the framework for current and future decisions about the monument and its boundaries for several reasons: the monument was established before the area was known to be highly mineralized and mineral resources were thus not considered in drawing boundaries; continuing retreat of some of the major glaciers every year exposes more bedrock that may contain pre viously concealed mineral deposits, and much of the monument consists of terra'n that is extremely difficult to prospect and explore.
A-l 15' -
FIGUR_E AH. MAP OF GLACIER BAY NATIONAL MONUMENT DEPOSITS, OUTLINES OF AREAS FAVORABLE FOR MINERAL DEPOSITS, GEOPHYSICAL ANOMALIES.
A-2 so'
SIGNIFICANT MINERAL DEPOSIT it "">*., MINERAL DEPOSIT WITH IDENT- f I RED" R£SOURCES DISCUSSED IN TEXT OR TABLE AH.
AREA CONTAINING KNOWN MIN ERAL DEPOSITS AND FAVOR ABLE FOR THE DISCOVERY OF ADDITIONAL HYPOTHETICAL* RESOURCES ON GEOLOGIC AND(OR) GEOPHYSICAL ANDCOP' »* OO GCOCHEMICAL GROUNDS
AREA FAVORABLE FOR THE DISCOVERY OF ADDITIONAL SPECULATIVE* RESOURCES ON GEOLOGIC ANOCOR) GEOPHYS ICAL AND(OR) GEOCHEMICAL WOUNDS
AREA WITH IMPORTANT P) GEOCHEMICAL ANOCOR) GEOPHYSICAL ANOMALY
58° 30'
RESOURCE TERMS DEFINED AS FOLLOWS WILDERNESS STUDY AREA, ALASKA, SHOWING SIGNIFICANT MINERAL AND AREAS WITH IMPORTANT UNCHECKED GEOCHEMICAL ANDCOR) A-3 The monument includes a variety of environments favorable for metalliferous mineral deposits and contains significant known magmatic segregation, porphyry-molybdenum, porphyry-copper, vein-gold, base- metal skarn, volcanogenic-base-metal, and beach-placer deposits. It also includes environments favorable for coal, oil and gas, geothermal energy, and industrial minerals, but our investigations suggest that none of these are likely to be present in amounts of economic signifi cance. This report presents pertinent geological, geochemical, geo physical, and engineering-sampling information derived from a joint U.S. Geological Survey-U.S. Bureau of Mines study of the area conducted from 1975 to 1977. It also synthesizes this information to evaluate seven favorable areas containing identified mineral resources and eight other areas considered to have undiscovered resources. This study builds on the studies done by the Geological Survey in 1966. Geological Survey studies reported here included reconnaissance geologic mapping, reconnaissance bedrock geochemical sampling, stream sediment sampling, and field examination of a few of the mines, pros pects, and metallic mineral occurrences studied in more detail by the Bureau of Mines. The geochemical investigations included collection, processing, analysis and interpretation of 1,895 stream sediment and 1,873 bedrock samples. Statistical analysis identified 331 stream sediment and 410 rock samples as containing anomalous amounts of one or more significant elements. A-4 Bureau of Mines mining-engineering studies included mining claim record search; on-site claim, mine, and prospect investigations; mapping and sampling of stained zones, altered zones, and geochemically anomalous sites; and evaluation and interpretation of private reports concerning mines and prospects. About 1,450 representative samples were collected, analyzed, and interpreted. About 1,200 claims, most of them lode, have been recorded in the Haines and Juneau recording districts as being within the area studied. A special effort by the U.S. National Park Service determined that about 200 were active in 1977. Between 240 and 275 kilograms (7,000 and 8,000 ounces) of gold were produced from the Reid Inlet gold district between 1938 and 1970, and about 140 kilograms (4,000 ounces) of gold and an unknown amount of platinum were produced from the Pacific Coast beach placers between 1890 and 1917. Figure A-l and Table A-l show the locations and summarize the TABLE A-l NEAR HERE. identified and undiscovered mineral resources estimated from the studies. The Bureau of Mines prepared the estimates of identified resources and the Geological Survey those of undiscovered hypothetical and speculative resources. The favorable areas shown as containing hypothetical resources on figure A-l represent consensus between the Bureau and the Survey. The following resource terms are used in accordance with the joint Bureau of Mines-Geological Survey resource classification scheme: identified, undiscovered, indicated, inferred, hypothetical, and speculative. A-5 TABLE A-1. IMPORTANT MINERAL DEPOSITS AND FAVORABLE AREAS, SIZE MCA FAVORABLE FOR DEPOSITS WITH MINERAL DEPOSITS SO ESTIMATED AMOUNT OF DIFFICULTY OF IDENTIFIED RESOURCES (KEYED TO FIGURE A-l ) HECTARES MILES MINERAL EXPLORATION MINERAL EXPLORATION ORE ENVIRONMENT {KEYED TO FIGURE A-l) A. PACIFIC BEACH SANOS 2.070 a Beck beach deposits are Modem bare beaches are Heavy Minerals Including A total of approximately little explored; since easy to explore and sam gold, tlmenite and report 4,000 oz of gold worth 1890 t toUl of 191 claims ple; dense vegetation ed platinum occur in Mod $75,000 was recovered have been located on the impedes exploration of ern and back beach sands from the beach sands de beech deposits; in 1977 back beach deposits of tfte coastal plain be posits between 1890 and 136 clilns were actively tween Sea Ottar Creek and 1917 by small-scale »1n- held Icy Point. Pocket beaches 1ng operations; Identi between Icy Point and fied resources ire calcu Dlxon Harbor also contain lated for 12 blocks with concentrations of heavy a total area of 260 hec Inerals tares (1 sq »1); two areas (1, 2 of fig. A-l) i within those blocks con tain higher than overall average grade and their resources are listed to the right 8. CRIUOK-IA PEROUSE 24 ,£00 95 Very little Extremely difficult. Layered cumulus-type gab- BRADY SLACIER NICKEL- Rugged high Mountain bro complex of unknown age COPPER MA6MATIC SEGREGA- glacial ten-tin; excel with known MgMtlc segre TION DEPOSIT (3 on fig. lent rock exposures in gation nickel-copper de A-1) places posit in perldotlte-Hch pert; iron, cobalt, chro- 1u* and platinum group eta! deposits also possi ble C. MOUNT FAIRMEATHER 2.350 9 Extremely little Extremely difficult; Same as CRILLON-LA PEROUSE None Portion in monument) very nigged high noun- favorable area tain glacial terrain D. MAR6ERIE SLACIER 15.700 60 Very Httle Moderate to difficult; Complex clastic, volcanic, MAR6ERIE SLACIER COPPER 'Porphyry -copper rugged fiord and high and carbonate section of PORPHYRY DEPOSIT {4 on environment) Mountain glacial terrain, Perm1an{?) age Intruded and fig. A-l) excellent rock exposures metamorphosed by Tertiary 1n places and Cretaceous granitic plutons and dikes with knowmToooerlporphYry ( and zinc-copper volcanogenlc deposits A-6 GLACIER BAY NATIONAL MONUMENT WILDERNESS STUDY AREA, ALASKA RESOURCES: ESTIMATED TONNAGE. SHADE AND 6ROSS-IN-PLACE-METAL VALUE (GIPWV)^ IDENTIFIED UNDISCOVERED INFERRED HYPOTHETICAL SPECULATIVE OTHER DEPOSITS; INDICATED SEOCHEMICAL, GEO CTRIC TONS (TONS) NETXIC TONS (TONS) METRIC TONS (TONS) METRIC TONS (TONS) PHYSICAL ANOMALIES (tone estimated (a) 4.6 Billion > (6 Billion yd') 70 Billion B> (90 Billion yd1 ) None estlMted containing 1.01 11»en1te. minor gold. containing 11 llnenlU. Blnor The above Includes: gold (b) -153,000 B» (200.000 yd') containing 3.41 11»enite at local ity 2 and (e) 102.000 B* (134.000 yd') containing 4.21 ilaenite. some gold. Values ir«: (a) $1.1 l/m3 (S0.8S/ yd'), (b) 13.83/B' ($2.92/yd 3 ). (c) $S.22/B» (J3.9J /yd') W Billion (90 Billion) 80 Billion (90 Billion) 80 Billion (90 Billion) None fstlMted Numerous showings of cop Each category containing 0. 531 nickel, 0.331 ctipper. and an wisp*elf led atount of platlnuai group per, nickel, tltaniun and etals Iron Blneralization 1n the west and north portions of GIPMV $2. 5 billion SIP"* $2.5 billion Gimv $2.5 b1U1on the area None estlMted None estimated None estlMted 82 Billion (96 Billion) Numerous specimens of containing 0.531 nickel and glacial float frow sev 0.331 cooper eral locations Indicate concentrations of copper, nickel, chroaJuM and alatlnui; large copper- Stained zones observed near the contact fre* a distance; very prominent aeromagnetlc anomaly; co balt, chromium, copper, nickel bedrock geocheni- cal anomalies not far to vest None estlMted 145 Billion (160 Billion) 45 Billion (50 million) None estlMted In order of significance: containing 0.21 copper. 0.27 containing 0.4S copper Tarr Inlet knob copper- g/Mt. ton (0.008 oz/ton) gold, zinc-s liver-gold pros 4.5 g/mt. ton (0.13 oz/ton) pect; Molybdenum bedrock silver. 0.011 tungsten; plus and float geoehemical higher grade parts; 6IPMV: ancMlies both sides JO. 8 billion Johns Hopkins Inlet; 21 PPB gold stream sediment anomaly north side sane Inlet; nwerous other copper, zinc, silver, gold, tungsten showings; other silver, gold, chro- Biun, copper, aercury. nickel, lead, tin. tung sten bedrock geochemical anomalies A-7 TABLE A-1. IMPORTANT MINERAL DEPOSITS AND FAVORABLE AREAS, GLACIER SIZE AREA FAVORABLE FOR DEPOSITS KITH MINERAL DEPOSITS SQ ESTIMATED AMOUNT OF DIFFICULTY OF IDENTIFIED RESOURCES (KEYED TO FIGURE A-1 ) HECTARES MILES MINERAL EXPLORATION MINERAL EXPLORATION ORE ENVIRONMENT (KEYED TO FIGURE A-l ) 1. MAR6ERIE GLACIER - StM 1 rea Vtry little Saae as above Massive sulfide showings ORANGE POINT VOLCANOSENIC Contlnued is abo« in volcanic rocks; gold, ZINC-COPPER DEPOSIT (5 on (Volcanogenic sulfide copper, beryllium stream fig. A-1) environment) sediment geochemlcal anom alies E. M/WfiERIE GLACIER - 6, WO 25 Very little or none Difficult; precipitous Sane as *0' above None Northeastern exten terrain, thick glacial sion deposits at lower eleva tions F. MARGERIE GLACIER - 10,200 39 Very little or none Difficult; precipitous Sane as *0' above None Southern extension terrain and extensive glacier cover 6. REIO INLET 10.380 40 High to Moderate; ouch Easy to Moderately diffi Narrow, discontinuous sul- Mining in the 1940's fron early surface prospecting cult. Most outcropping fide-bearing quartz veins the surface and shallow veins have been found, in altered- granitic rock underground workings re but not all have been ex of Cretaceous age and horn- sulted in 220 kg (7,150 plored; deposits not ane- felsic rock of Paleozoic oz) of gold being pro Mble to geophysical or age duced, wstly fro* the geocheMleal prospecting LeRoy (7 on fig. A-l) and Rainbow nines H. RENOU GLACIER 2,500 10 Very little or none Difficult to very diffi Discontinuous carbonate Massive chaleopyrite" cult; although very rugged lenses in Devonian or copper-tungsten skam terrain, deposits are ane- Silurian clastic rocks deposit (6 on fig. A-]) nable to agnetoaeter occur near and next to prospecting Cretaceous and perhaps Tertiary granitic rocks; hign-grade skam-type tungs ten-copper-si Iver- gold-zinc deposits of unknown extent occur in the contact zone Moderate Easy, except for extensive Discontinuous carbonate ALASKA CHIEF COPPER SXARN brush and tiMber lenses in Devonian or DEPOSIT (8 on fig. A-l) Silurian elastic rocks near Tertiary granitic body contain skam depos its with copper, gold, silver, zinc I. MUIR INLET 39,700 153 Probably wore than other Moderate; excellent rock Paleozoic clastic and car THE NUNATAK MOLYBDENUM parts of the «onupent exposures; Moderate relief bonate rocks intruded and DEPOSIT (9 on fig. A-l) hornfelsed by Cretaceous and Tertiary dikes; wide spread alteration and frac turing; known olybdenuM- copper-porphyry type stock- work and disseminated nin- eralization. Vein type copper, Molybdenum, silver, tungsten and replacement or skarn-type copper-zlnc- tungsten deposits also pos sible A-8 BAY NATIONAL MONUMENT WILDERNESS STUDY AREA, ALASKA CONTINUED RESOURCES: ESTIMATED TONNA6E. GRADE AMD GROSS- IN-ftACE-METAL VALUE (GIPMVh^ IDENTIFIED UNDISCOVERED INDICATED INFERRED HTPOTHETICAL SPECUtATIVE OTHER DEPOSITS; 6EOCHEMICAL, GEO CTRIC TOMS (TONS) METRIC TONS (TONS) METRIC TONS (TONS) METRIC TONS (TOfIS) PHYSICAL ANOMALIES None estimated 250,000 (270.000) 0.9 ullllon (1 million) None estimated Massive sulflde showings containing 2.7f copper, 5.21 zinc. containing 1.5X copper and 2.01 In volcanic rock My In 1 g/met. ton (0.03 oz/ton) gold. zinc dicate additional volcan- 34 g/Mt. ton (1 oz/ton) silver ogenlc deposits; gold, and copper, beryl Hun stream 470,000 (530.000) sediment geochemlcal containing 0.41 copper. 0.31 zinc. anomalies 0.2 g/Mt. ton (0.006 oz/ton) gold. 12 g/«et. ton (0.35 oz/ton) silver; 6IPW: $20-25 million None estlMted None estlMted None estimated Copper; unquantlfled Tungsten, BolyodenuB. stream sediment anomalies None estlMted None est tMted None estlMted Copper and zlnc; unquantlfled None None estlMted None estimated About 480 kg (14,000 oz) of None estlMted Highland Chief. Russell gold in District as a whole Island, Raafaler and numer ous other lode gold show ings, son* placer pros pects; gold, copper stream sediment anomalies Won* estlMted 3,800 (4.300) None KtlMted Copper and tungsten; (^quan Float and In place samples containing 0.5S tui ngsten, 5. OS tified indicate extensive are* of copper. 240 g/Mt. tor. (7 oz/ton) high temperature tungsten, silver, 5.2 g/wt. ton (0.15 oz/ silver, zinc, and gold ton) gold; GIPHY: $900.000 mineralization extending Intermittently for at least 3 h» (2 Bl) 24,000 (27,000) None esti nated None estlMted None e stlMted None containing 1 1 copper. 3.4 3/met. ton ( 0.1 oz/ton) (Old. 69 g/met. ton (2 oz/ Mm) silver 7.4 million (8.2 million) 8.3 dUlon (9.1 dlllon) 90 million (100 Million) None « stlMted Brace Hills copper-molyb- containing t .06* nolybde- containing 0.061 nolyMenun and containing 0.1 5-0. MX nolyb- denuB prospect; molybdenum NUB and 0.02J copper; 0.021 copper denm stream sediment anomalies; and copper, mercury, nickel. 124 Million (137 million) tungsten, rock geochemlcal :ofititn1ng 0.041 molyfade- anomalies In part of area; nm and 0.02* copper numerous copper-mo lybdenua showings Including Gable GIPMV: $550 million Mountain and Uachusett Inlet A-9 TABLE A-1. IMPORTANT MINERAL DEPOSITS AND FAVORABLE AREAS, GLACIER AREA FAVORABLE FOR SIZE DEPOSITS WITH MINERAL DEPOSITS SO ESTIMATED AMXJNT OF DIFFICULTY Of IDENTIFIED RESOURCES (KEYED TO FIGURE A-1) HECTARES MILES MINERAL EXPLORATION MINERAL EXPLORATION ORE ENVIRONMENT (KEYED TO FIGURE A-1) }. MUIR INLET EXTEN 55,400 214 As above As above Slullar to above, but None SION fever dikes and less frac tured ground K^CASEMENT 6LACIER 61,500 238 Very little Moderate to difficult due Similar to above None fftoTyBaSuSKporphyry./ to inaccessibility, exten environment)"- sive glacier cover L. CASEMENT GLACIER - 12,600 49 Ivy little As above Complex clastic, volcanic None Continued and carbonate section of Penalan age Intruded and etaaorpnosed by Tertiary and Cretaceous granitic pi u tons and some dikes. Environment for volcano- genie sulflde deposits similar to ORANGE POINT. (See area *D*) N. UNITE 6LACIER 2.300 9 Little Moderate to difficult due Sa«e as *L* above None to steep terrain; sone glacier cover, brush and timber at lover elevations N. MOUNT ESCURES Little Moderate; timber and brush Cretaceous graywacke, slate Hone Intruded by granitic stocks 0. CAPE SPENCER Little Moderate; steep brush* and Blotlte schist and gneiss None NORTH tlaMr-covered slopes of unknown age Intruded by Tertiary and Tertiary and (or) Cretaceous granitic stocks P. EXCURSION RIVER Sow; In southern part of Moderate Graywacke and argil lit* of None area Silurian age with carbon ate lenses; sawll granitic plugs -'6IPHY MEANS Gross-In-Place-Metal-Value; this Is arrived at by Multiplying estimated tonnages of resources present by combined dollar value per ton at A-10 BAY NATIONAL MONUMENT WILDERNESS STUDY AREA, ALASKA CONTINUED RESOURCES: ESTIMATED TONNAGE. SRAM AND GROSS- IN-PLACE-METAL VALUE (GIPMV)^ IDENTIFIED UNDISCOVERED OTHER DEPOSITS; INDICATED INFERRED HYPOTHETICAL SPECULATIVE SEOCHEMICAL. GEO cntic TONS (TONS) METRIC TONS (TONS) METRIC TONS (TONS) METRIC TONS (TONS) PHYSICAL ANOMALIES None e stlMted None est Mted None «istlMted Molybdem»-coipper; unquantl- Molybdenw ttrem sedlnent fled jeocnealcal anon* lies Norn « StlMted None est Mted None iKtlMted Molybdenu«v None «rstlMted None est Mted None i StlMted Zinc, copper; iwqu«nt1f1ed None Hen* ««tlMt*d None est Mted None KtlMted Z1nc. copper; unqgantlfled MiUe Slacler ttriUbound zlnc-copper-sllver pros pect; copper. olyMentM, lead, cobalt. chro*1w, nickel. Mtxury strttm sedlnent jeochcBlcal ano»- 11es In part of area NOM « stlMted None est Mted None «KtlMted None estlMted Cotalt. chnwlua, copper, nickel, zinc, nercury streea sedlnent and bed rock geochenfcal anoma lies None « stlMted None est Mted None prices of all the elements of econonlc Interest present In the deposit. It Is not a M«sure of tne net xortti of a deposit. A-n i Four deposits with important identified mineral resources are known, (in the monument. They are, from west to east, the Brady Glacier nickel-i jcopper deposit in the Fairweather Range ( 3 on fig. A-l and table A-l) , the Margerie Glacier copper deposit near Tarr Inlet ( . 5) , the , ; i I Orange Point zinc-copper deposit on Johns Hopkins Inlet ( 6) , and thei Nunatak molybdenite deposit (. 9). These identified resources are estimated to underlie less than 0.1 percent of the total area of the monument. : i i The Brady Glacier nickel-copper deposit (3 on fig. A-l) is a largely glacier-covered magmatic segregation sulfide occurrence in peridotite land gabbro at the base of the Crillon - La Perouse layered gabbro complex of unknown age. The deposit is estimated to contain 80 million metric itons (90 million tons) of indicated resource with 0.53 percent nickel, 0.33 percent copper, and an unspecified amount of platinum group metals ' (PGM). An additional 80 million metric tons (90 million tons) of inferred resource of the same grade are also likely to be present. The Margerie Glacier copper deposit (4 on fig. A-l) is a fairly well exposed porphyry-copper occurrence in granitic rocks of probable Tertiary age. The deposit is estimated to contain 145 million metric tons (160 million tons) of inferred resource with 0.2 percent copper, 0.27 grams per metric ton (0.008 ounces per ton) gold, 4.5 grams per metric ton (0.13 ounces per ton) silver, and 0.01 percent tungsten. Higher grade sulfide-bearing quartz veins occur within this large volume. A-l 2 9-1247 1 ! The Orange Point deposit (5 on fig. A-l) is interpreted to be a z J moderately well exposed metamorphosed andesites of Permian (?) age. The Ideposit is estimated to contain 250,000 metric tons (270,000 tons) of ~~ iinferred resource with 2.7 percent copper, 5.2 percent zinc, 1.0 grams i 6 per metric ton (0.03 ounces per ton) gold, and 34.3 grams per metric 7 ton (1.0 ounce per ton) silver, and 470,000 metric tons (530,000 tons) 3 of inferred resource with 0.4 percent copper, 0.3 percent zinc, 0.2 'grams per metric ton (0.006 ounces per ton) gold, and 12.0 grams per 10~ metric ton (0.35 ounces per ton) silver. \ The Nunatak molybdenum deposit (9 on fig. Arl) is a porphyry- ' : molybdenum occurrence in hornfels of original Early to Middle Paleozoic ' 3 age and is probably related to nearby Tertiary granitic bodies. The 14 .well-exposed deposit is estimated to contain 132 million metric tons 5~;(145 million tons) of indicated resource with 0.04 to 0.06 percent M molybdenum and 0.02 percent copper accessible to surface mining and an additional 8.3 million metric tons (9.1 million tons) of inferred resource containing 0.06 percent molybdenum and 0.02 percent copper "' below sea level near shoreline. Within this volume is a potentially :: ~~ important higher grade section that, if taken by itself, would have to -' be mined underground. A-l 3 9-1267 i Five areas considered to contain significant undiscovered 2 hypothetical resources are recognized within the monument. They are, 3 from west to east, the Crillon - La Perouse (B on fig. A-l and table JA-1) , Margerie Glacier (D) , Reid Inlet (G) , Rendu Glacier (H) , and Muir s Inlet (I) favorable areas. Just as the identified resources underlie 4 only a small part (0.1 percent) of the total area of the monument, any r other resources present and discovered in the future in these i hypothetical resource areas would similarly underlie a small part; even -> though the favorable areas themselves cover about 8 percent of the :G_ monument. A-14 9-1267 Six areas considered to contain undiscovered speculative resources are recognized within the monument. They are, from west to east, the , Mount Fairweather (C on fig. A-l and table A-l), Margerie Glacier north- 4 eastern extension (E), Margerie Glacier southern extension (F), Muir Inlet extension (J), Casement Glacier (K and L), and White Glacier (M) favorable areas. As with hypothetical resources, any resources present and discovered in the future in the speculative resource areas would underlie a small part of the monument; even though these favorable areas .^ themselves cover about 13 percent of the monument. Three other areas (N, O, and P on fig. A-l and table A-l) contain i- previously unknown geochemical and(or) geophysical anomalies that may 2 indicate the existence of undiscovered resources, but the anomalies have 3 not been field checked. : ; - Geologically, the monument is extremely complex, reflecting a long in part :=-- history of sedimentation, volcanisrn, intrusion, and deformation/near the i- boundary between the North American continental crustal plate and the Pacific oceanic crustal plate. Layered sedimentary and volcanic rocks range from unknown, but perhaps Precambrian, age through Pleistocene, with apparent large gaps in the late Paleozoic and early and middle Mesozoic. The layered rocks were in general deposited in fairly deep marine environments; some of the Paleozoic volcanic rocks and reef carbonates and some of the Tertiary rocks near the Pacific coast are - - exceptions. A-l 5 Intrusive rocks range from unknown, but perhaps Precambrian, age through middle Tertiary, with the major subdivisions being: 1) layered cumulus-type gabbro complexes of unknown age in the Fairweather Range, i 2) foliated granodiorite, quartz^monzodiorite, tonalite, and quartz 5 - diorite of mid-Cretaceous age, 3) locally foliated granodiorite and 6 tonalite of Tertiary or Cretaceous age, and 4) unfoliated granite and 7 granodiorite of mid-Tertiary age. 8 Four major fault zones occur in the monument: the Fairweather 9 fault near the Pacific coast is an active major post-Mesozoic structure 10 - that plays an important role in present-day northeastern Pacific 11 tectonics; the Tarr Inlet suture zone in the western part of the monument 12 is an apparently post-Permian, pre-mid-Cretaceous structure between two :3 unlike crustal blocks and is also the site of Tertiary faulting; 14 the Glacier Bay fault parallels the west side of Glacier Bay 15~~ proper and separates metamorphosed and unmetamorphosed rocks of the same 16 age; and a zone of west-striking faults occurs in the northeastern_ 17 part of the monument. A-l 6 9- ',257 ! Interpretation of the aeromagnetic data indicates that most of the magnetic anomalies are caused by either plutonic or volcanic igneous rocks. Closely spaced broad subcircular highs in the eastern part of 4> the area correlate with Cretaceous or Tertiary granitic intrusives. An i important north-trending broad magnetic gradient that slopes down 5- ; to the west marks the western edge of the magnetic Cretaceous granitic o rocks near the Tarr Inlet suture zone. It is the eastern boundary of an . area of weakly magnetic rocks which is adjoined on the west by a series 9 of elliptical magnetic highs caused by the layered gabbro complexes. I 0 Calculations suggest that the four exposed gabbro bodies are part of a .. larger concealed mass with steep outward-dipping contacts that extend to a depth of at least several kilometers. I 2 Interpretation of the gravity field shows that 1) the prominent linear high of the Fairweather Range may be caused by the layered gabbro complexes extending to several kilometers depth with either near-vertical or steep outward-dipping contacts, 2) the dense high-grade metamorphic rocks near Dundas Bay have a strong local effect, and 3) all of the Geikie province is underlain at shallow depth by granitic rocks. Ice thickness measurements on the Brady Glacier and elsewhere indicate that there is over 900 m (2,900 feet) of ice at several localities and that 1) the sub-ice surface beneath the Brady Glacier is probably everywhere below or close to sea level and (2) a thickness of inore than 1,000 m (3,280 feet) of ice occurs in the glacier basin directly north of the Brady Glacier nickel-copper deposit. A-L7. 9- ',257 The geochemical studies identified 15 areas with anomalous concentrations of one or more elements in stream sediments and 10 areas with similar concentrations in bedrock samples. Stream sediment study results are influenced by the sparse sample coverage in the parts of 5 __ the monument that were studied mainly in 1966. Four areas already known from earlier studies to contain significant anomalies were verified and three new areas were identified as having significant anomalies that have not been field checked. A-18 9. ;2S7 1 Introduction 2 The Glacier Bay National Monument Wilderness Study area includes 3 all of Glacier Bay National Monument, an area of about 1,140,000 i 4 hectares (4,400 square miles or 2,817,000 acres) (U.S. National Park i i 5 .Service, 1975). The monument is an area of rugged glacier-clad mountains, 6 steep-sided fiords, and heavily forested lower mountains in the Pacific : Border Ranges physiographic province which lies between the Gulf of 3 Alaska and the inside waters of southeastern Alaska. The monument was ? established in 1924 to preserve a scenically and glaciologically :;,_outstanding part of Alaska. The monument was open to mineral entry from : 1936 until 1976 and has been visited by numerous geologists and 12 prospectors, as described later in this report. The Park Service .3 currently (July 1977) manages all of the monument (with the exception of u the headquarters area) under an administrative designation that is ; similar to formal wilderness status. 16 The mineral resources of the monument have been described in various :- reports and a major study in 1966 by the Geological Survey provided ;- information to the National Park Service for use in planning the future - management of the monument for the public; some of the material resulting from that investigation (MacKevett and others, 1971) is incorporated in this report and the present studies build on the 1966 _: work. , This report focusses on the mineral deposits of the monument and presents mineral resource information pertinent to possible future wild erness classification and to definition of wilderness area boundaries. The Geological Survey also plans to publish a more detailed geologic map of the monument and a report on the distribution, mineralogical and chemical " compos, ijfciojn ,_and_age_o_f_iatriisiye_XQC^ - : 9.1267 Access, use, and general character 2 Glacier Bay National Monument is centered about 160 km (100 miles) 3 west-northwest of Juneau, Alaska (fig. A-2) and can be reached only by Figure A-2 near here air or water. Ships and boats can reach Glacier Bay proper from Inside Passage waters through Icy Strait. The Pacific coastal part of the monument is reached either directly from the Pacific or via an exposed run out Icy Strait and around Cape Spencer into the open ocean. Charter float-equipped aircraft from Juneau and other communities fly into the monument with landings possible in most fiords except those where icebergs are numerous or where the Park Service limits motorized travel. Ski-wheel aircraft have landed on some of the glaciers; such landings, and helicopter landings must be cleared with the Park Service in advance. Alaska Airlines provides regularly scheduled air service all year to Gustavus, a nearby permanent community connected by road to the monument headquarters village at Bartlett Cove. Other than at the monument headquarters, the only human activities in the study area are temporary and are either recreational, related to scientific research, or to commercial fishing. Prior to the September 1976 closure to mineral location, there was some related activity every year. By far the greatest number of visitors to the monument are on large cruise ships, which now make regular visits to Glacier Bay proper. A-' BAY NATIONAL MONUMENT I J7*OO SI'00' OS '»»$ 20HIUS \ \_ :«fe^S*«nc«rS*«nc«r S V \ 'V Xi \ I Figure A-2. Index map showing Glacier Bay National Monument. Alaska, and geologic provinces within the monument. A-21 3-1267 Of the 1,140,000 hectares (4,400 square miles) total, about 137,300 hectares (530 square miles) or 12 percent is covered by 80 km- (50 miles) long Glacier Bay itself and its contiguous fiords and inlets and about 129,500 hectares (500 square miles) or 11 percent are waters of the ; Pacific Ocean, Cross Sound, Icy Strait and adjoining bays. Of the remaining land area of 873,000 hectares (3,370 square miles), at least 215,000 hectares (830 square miles) or 19 percent are covered by glaciers, a situation that is abundantly clear on plate la. Much of the 3 remaining 658,000 hectares (2,540 miles) or 58 percent is covered either by forest or by snow all but a few months of the year. Glacier Bay National Monument is renowned for both its spectacular glacier-covered mountains and its valley-filling tidewater glaciers. The magnificant Fairweather Range culminates in Mount Fairweather (4,665 m or 15,300 feet) and forms an awe-inspiring divide (fig. A-3) between Figure A-3 near here the Gulf of Alaska and the deep fiords of Glacier Bay proper. The rapid recession of the tidewater glaciers (Streveler and Page, 1971), as typified by Muir Glacier in Muir Inlet (fig. A-4), and the glacial and Figure A-4 near here other natural phenomena associated with the recession make the monument a classic area for scientific studies. A-22 Figure A-3. Photograph looking northeast across Lituya Bay at the crest of the Fairweather Range; Mount Fairweather on the left * and Lituya Mountain on the right. A-23 Figure A-4. Photograph looking north up Muir Inlet from the northwest shoulder of Mount Wright. The Nunatak molybdenite deposit is on the isolated prominent peak in the right middleground. A-24 9. '.257 Figure A-5 near here The climate of the southern and lower altitude parts of the monument is maritime, while the northern rain-shadowed part is less humid and probably has greater temperature extremes. Weather records show that the months from February through July or August have the least precipitation, and the fall and early winter months have the most. Temperatures are generally mild. From June through August there is likely to be abundant local fog, overcast skies, low clouds, and relatively few clear, blue-sky days. Winds can be strong locally. A few areas, most notably Excursion Inlet and Mount Marchainville at the south end of the Fairweather Range, were found to have consistently poor local weather during our field operations. Further description of the general character of the monument is given in MacKevett, Brew, Hawley, Huff, and Smith (1971, p. 7-8). A-25 £sfv^« . ; ... . .t*^.»j«iT!aili1*tto'J^^.:' M -^v»», *,.:,. Figure A-5. Oblique aerial photograph looking west at the southwestern part of the Brady Glacier Icefield, showing Mount LaPerouse on the x" " "s right and the Brady Glacier /copper-Jnickel^-deposit nunatak in the left center. A-24 S. ',257 Previous .studies MacKevett, Brew, Hawley, Huff, and Smith (1971, p. 8-9) described the pre-1966 investigations in the monument as follows: "Glacier Bay has attracted many geologists and glaciologists during the past 90 years, mainly because of the rapid recession of the glaciers. Few of the earliest explorers and scientists came with economic interests in mind, but by 1892 some prospectors were in the area (Possman, 1963b). In 1906, F. E. Wright and C. W. Wright (1937) studied the Johns Hopkins Inlet area and other parts of the monument; in 1917, J. B. Mertie visited the area (Mertie, 1933). Buddington (Buddington and Chapin, 1929) visited the monument in 1924. Somewhat later, several other Geological Survey geologists (Reed, 1938; Twenhofel. and others, 1949; Kennedy and Walton, 1946) visited specific mineral deposits then of interest or under development. Economic interest in the monument was lessened by prohibition of prospecting from 1924 to 1936. "In 1942, Twenhofel (1946) studied the Muir Inlet Nunatak molybdenum deposit in detail, and the U.S. Bureau of Mines sampled the deposit (Sanford and others, 1949). In 1949, D. L. Fossman began geologic studies in the monument, which are summarized in three reports (Possman, 1959, 1963a, b). In 1950-51, J. F. Seitz studied the geology around Geikie Inlet (Seitz, 1959). Don J. Miller studied the Gulf of Alaska Tertiary province for several years; his mapping within the monument was incorporated by Possman (1963a) after earlier open-filing (Miller, 1953, 1961). A-27 9-1267 Reconnaissance studies in the Juneau 1:250,000 quadrangle part of ' the monument were, made during the period 1956-58 (Lathram and £. , , others, 1959). A few mining companies, notably Fremont and Moneta- 4 Porcupine, prospected in the monument during the late 1950's and 5 _ ; early 1960's." ^ In addition, Thomas and Berryhill (1962) sampled Pacific beach ; were , sands. Other investigations/made by mining engineers of the Territorial a Department of Mines (TDM) (the Territorial forerunner of what is now the 9 State Division of Geological and Geophysical Surveys) and lay private 10 _ parties. The TDM reports are available to the public and have been used ;i by the U.S. Bureau of Mines in discussions of various prospects in 12 Glacier Bay. They include examinations on Willoughby Island by Shepard 13 (1926) ; near Dundas Bay by Stewart (1949); and of the LeRoy mine by Roehm u (1942), Fowler (1950), and Holdsworth (1955); and of the Sandy Cove [r _ prospect by Nelson (1935). \ A-2 3 9.1257 Since the .preparation of the 1971 report, there has been only one 2 published report dealing with mineral deposit's in the monument: Plafker 3 and MacKevett (1970) described what was then known about the mineralized a. rocks of the layered gabbro body at Mount Fairweather. Three other 5 _'reports (Plafker, 1967; MacKevett and others, 1974; Reimnitz and Plafker, 5 1976) deal in part with hydrocarbon and metallic mineral deposits in 7 nearby areas. Several short papers of general geologic interest have g been published since 1971 (Brew and Ovenshine, 1974; Brew, Carlson, and 9 Nutt, 1976; Brew, Grybeck, and others, 1976; Brew, Loney, and others, 1G _ 1977; Brew, Johnson, and others, 1977; Brew and others, 1978; Brew and 11 Morrell. 1978;Page, 19j) . The listing from MacKevett and others (1971) and this 12 list do not include papers concerned primarily with glacial geology. ; :j Several mining exploration companies, including Fremont Mining Co., u Bear Creek Mining Co., Superior Oil Co., Alvenco, Inc., Moneta-Porcupine 15_ Mines, Ltd., Cyprus Mines Corp., American Exploration and Mining Co. (Amex), Anadarko Production Co., and Newmont Exploration, Ltd., have investigated parts of the monument; some of their activities are ;i discussed in Chapter C. Acknowledgments As in 1966, the cooperation of the U.S. National Park Service :: staff at Glacier Bay National Monument contributed to the efficiency of 23 our field operations. We particularly thank Tom Ritter, Superintendent, :4 Charles Janda, Ranger, and Greg Streveler, Research Biologist. A-29 9-1267 I The U.S. Bureau of Mines acknowledges the aid of Albert F. Parker i 1 j Iand his daughter/ Jeanne Trump, in showing their LeRoy mine and Highland 2 I I Chief properties, and consultants George A. Moerlein and Leo Mark i 3 ! Anthony for information regarding several mineralized localities. i ; The crew of the U.S.G.S. R/V Don J. Miller II provided expert i 5_ I support to the field parties. Thanks are extended to R. D. Stacey, i Master, 1975-76; R. L. Robeck, Master, 1977; E. C. Magalhaes, Senior Engineer; E. M. Kuehn, Cook-Seaman, 1975; Greg Spector, Cook, 1976; and O ' I ^Richard Loso, Seaman, 1976-77. Entry and initial retrieval of the geo- ? ' ! chemical data were directed by S. K. McDanal, computer specialist, iQ .Branch of Exploration Research, Golden, Colorado. The skill and judg- i] i ment of the helicopter pilots: C. H. Molvig, 1976; W. H. Springer, 1976; 12 ; and G. L. Hine, 1977, are gratefully acknowledged. 13 i : Analytical support was provided by the following U.S. Geological Survey Branch of Exploration Research personnel: C. L. Forn, spectro- ,grapher, 1975-77; J. C. Hoffman, chemist, 1975-77; R. F. Sanzolone, 'i i .chemist, 1977; P. R. Johnson, 1975, V. E. Kraxberger, 1976, and C. Nayudu, 1977, sample preparators. Geological Survey petrographic studies were " 5 by the authors, assisted by R. A. Sonnevil. Intrusive igneous rocks are classified according to the IUGS scheme (Streckeisen, 1973). Bureau of Mines sample preparation was by J. G. Mills and K. R. Weir. Bureau of Mines petrographic studies were by W. L. Gnagy and I 22 ' C. L. Mardock. Bureau of Mines fire assays were by C. W. Merrill, Jr. Special analyses were done by U.S. Bureau of Mines Reno Metallurgy ; i ' Research Center and Skyline Labs, Anchorage, Alaska. A-30 I The U.S. Bureau of Mines acknowledges the efficient support of the i 2 owners and operators of the M/V Blue Star, Hellen and Roland Burrows, i 3 during the independent operations in August 1976 and August 1977, and 4 also the skill and cooperation of the helicopter pilots: Walt Lasher in i 5_l976, and Mark Babcock in 1977. v A-31 9-1767 Chapter B j Geology, geophysics, and geochemistry ; Geology ! by ! Jc !1 David A. Brew I; 6 ! Introduction | 7 i This chapter briefly describes the geology of the monument, calls a {attention to the ore environments, and presents at length the results ! j I 9 jof the aeromagnetic, gravity field, and reconnaissance geochemical studies ii ! I '°~ | Present investigations j l i 11 | U.S. Geological Survey field studies had four main components: 12 jreconnaissance geologic mapping of areas not mapped in 1966; reconnais- i and \ 13 sance bedrock geochemical sampling in those areas^to a limited extent in 14 , previously mapped areas; stream-sediment sampling in previously unmapped i5 iareas and to a significant extent in previously mapped areas; and field 6 .examination of some of the mines, prospects, and metallic mineral | '~ . occurrences assessed in detail by the U.S. Bureau of Mines. With the 18' exception of independent Bureau of Mines field work, field operations ;: were conducted jointly from the U.S.G.S. R/V Don J. Miller II using 2° small boats and cooperatively shared contract helicopter support. 21 i In July and August, 1975 a Geological Survey party, consisting of -2 ;K. M. Blean, D. A. Brew, Christine Carlson, C. L. Forn, Donald Grybeck, 23 B. R. Johnson, and C. J. Nutt, was in the field 20 days. In June and i : 25- B-l 9-12*7 Nutt. Thirty-two days were spent in the field. The party in July and August, 1977, consisted of Brew, Ford, Johnson, R. P. Morrell, and R. F. Sanzolone and was in the field 26 days. A total of about 13 person-months was spent in 5_ the field. Reconnaissance geologic mapping was done on foot, from helicopter, and from small outboard-powered skiffs. Protected shores were traversed by skiff parties, most walkable ridges were traversed on foot, and other areas were mapped with fly-bys and spot landings by helicopter. In most of the Fairweather Range weather and terrain made the helicopter landings difficult and stations are therefore irregularly spaced. Reconnaissance bedrock geochemical sampling was done in conjunction with the mapping, except that a few days were devoted to sampling in 15 previously mapped areas. Each common rock type and all visibly mineralized and altered rocks were sampled at each station. Stream sediment samples were collected from all active streams in the newly-mapped area and about half of the streams in the previously mapped area were re-sampled. This investigation includes an aeromagnetic survey done under contract by LKB Resources, Inc. and the results of that survey and of a gravity field survey are interpreted in this report. Field studies in support of the geophysical surveys were from from the Don J Miller II in June 1976 by a party consisting of D. F. Barnes, Andrew Griscom, C. S. Gromme, and R. 9-1267 D. Watts. During parts of the 1975, 1976, and 1977 seasons, the Glacier Bay National Monument Wilderness Study Area project worked closely in the field with personnel of the La Perouse 5- layered gabbro project. R. A. Loney, G. A. Himmelberg, and G. K. Czamanske. Some of the results of their study of that gabbro body and of the associated Brady Glacier nickel-copper deposit have been incorporated in this report. 15 B-3 9-1267 Geologic setting Glacier Bay National Monument adjoins the northern end of i the Alexander Archipelago, southeastern Alaska, and its , i relationship with surrounding area is shown on the compilations of Brew (in Brew and others, 1966); Souther, Brew, and Okulitch (1974); and Beikman (1974). Recks ranging in age from unknown, but possible Precambrian,to Holocene occur in the monument, but available evidence suggests that the greatest volumes of rock are 1) unknown, but ! possible Precambrian or lower Paleozoic, 2) middle Paleozoic, 3) mid-Cretaceous, and 4) mid-Tertiary in age. General tectono- stratigraphic relations are sketched below and each of the five geologic provinces in the monument is described briefly. Descriptions of individual rock units are given in the explanation of plate la. - The eastern two-thirds of the monument is underlain by stratified rocks of late Silurian through Permian age that are 1) part of the central Paleozoic belt of Brew, Loney, and Muffler (1966), and 2) the Paleozoic part of the Alexander terrane as defined by Berg, Jones, and Richter (1972). These rocks are joined along a suture zone of apparent post-Permian, pre-mid-Cretaceous age (Brew and Morrell, 1978) to a large tectonic block in the western part of the monument containing rocks of unknown, but possible Precambrian or early Paleozoic, age (Brew, Loney, and others, 1977). This block is also 25 B-4 9-1267 considered part of the Alexander terrane, and along its western margin includes rocks which other authors (Jones and others, 1978) believe are early Mesozoic. The western margin of the block is the Fairweather fault which Plafker, Jones, Hudson, and Berg (1976) interpret to be the extension " of the Border * Ranges fault (MacKevett and Plafker, 1974). This is an j 7 important Mesozoic structure which in general juxtaposes upper j ; i Mesozoic rocks against lower Mesozoic and(or) upper Paleozoic rocks to ! ! 9 ; the northeast all the way from the Shumagin Islands around the 'o ! Gulf of Alaska. The block lying immediately west of the ' I Fairweather fault consists of undated, but probably upper 12 : Mesozoic, subduetion zone rocks belonging in part to the melange I !3 i facies of the [younger] Chugach terrane of Berg, Jones, and 14 ; Richter (1972). These rocks are overlain unconformably by I m \ <:-.1 Tertiary rocks (Plafker, 1971, in MacKevett and othersv).JA i6 i Current plate tectonic analyses suggest the Precambrian(?) :r through middle Paleozoic rocks of the Alexander terrane " ("Alexander plate") weie joined to the proto-North American plate in the Late Paleozoic (Monger, Souther, and Gabrielse, "- 1972) along a suture that lies far to the east of the monument 2- in interior British Columbia. The suture within the monument i 22 i described previously (Brew and Morrell, 1978) is apparently a -3 ; younger feature related to collision of two parts of the 2> Alexander terrane before mid-Cretaceous time. At that time or -.5- ! perhaps later the predecessors of the Kula, Farallon, and B-5 9-1267 Pacific plates (Atwater, 1970) were being subducted beneath the | Alexander plate (which was already joined to the North American 1 plate). The resulting subduction complex is contained in the [younger] Chugach terrane west of the Fairweather fault. That fault is 5 interpreted (Atwater, 1970) to be part of a system with right-lateral transform movement resulting from Tertiary migration of the spreading center-transform-subduction triple point northwestward towards its present location as the Pacific plate moved northwestward relative to the North American plate. 10 In the monument Tertiary movement has modified and obscured the original configuration of the Border Ranges fault. The distribution of intrusive rocks does not show a clear 13 relation to the plate-tectonic interpretation, although both the layered gabbros of unknown - . age and granitic rocks of mid-Tertiary age form generally north-trending belts in the western third of the monument. Granitic rocks of mid-Cretaceous age are more abundant and occur both in a north-trending belt east of the layered gabbro and Tertiary granitic belts and in a west-northwest-trending belt in the northeastern third of the monument. These blocks and intrusive belts are directly related to the geologic provinces in Glacier Bay National Monument as originally defined by MacKevett, Brew, Hawley, Huff, and Smith 24 (1971) and revised slightly in this report (fig* A-2). The JLituyA_Broyince,.^hich_JLs_a_new_name__f_o.r__t.he_Coas ta 1_ province,_._ B-6 9-1W lies west of the Fairweather fault and is composed of rocks of the [younger] Chugach terrane and the overlying Tertiary rocks. The Fairweather province.east of the Fairweather fault, consists of rocks of unknown but possible Precambrian or Early Paleozoic age belonging to the Alexander terrane, and is bounded on the east by the post-Permian, pre-mid-Cretaceous suture (called the Tarr Inlet suture). Immediately east of the suture is the Geikie province, which is differentiated from the easternmost Chilkat province by its abundance of Cretaceous granitic bodies. The Muir province adjoins the Geikie province north of the Chilkat province and is similarly set off from the latter by its abundance of Cretaceous granitic rocks. The Muir and Geikie provinces are separated on the basis of different structural « trends. The country rocks of the Geikie, Muir, and Chilkat provinces are part of the Silurian through Permian section of the Alexander terrane. A prominent north-trending belt of Tertiary granitic rocks straddles the Tarr Inlet suture (plate la). Evidence for the age of the rocks in Glacier Bay National Monument is sparse and uneven. Because no isotopic age data have been published, the ages of most granitic and some metamorphic rock bodies are inferred from field relations and 3*cl from preliminary isotopic age data of M. A. Lanphere (written^ commun., 1967). In the Lituya province, the Tertiary strata have been dated by fossils. No fossiliferous rocks are known 9-1267 in the Fairweather province and only non-diagnostic fossil fragments have been found in the Geikie province. Only a few scattered collections are available from the Muir province; however, in contrast, the Chilkat province has provided fossil | i collections from several stratigraphically and geographically i separated localities. ! No systematic discussion is given here of the surficial deposits, glacial features, or of the physiography. These topics are ! noted specifically in the discussions of the geochemistry, 10 i geophysics, and mineral deposits. j is ; B-8 9-1267 1 __L_ _ Lituya province A melange of unknown thickness consisting of JLarge blpcks_of__green-- stone, phyllite, graywacke, and chert up to 100's of meters ia.maximumi dimension is interpreted to be the oldest unit in the Lituya p.rov.in.ce_-^. (plate la). The unit is probably Cretaceous and belongs to the [younger] Chugach terrane of Berg, Jones, and Richter (1972). An apparently thick and coherent section of less metamorphosed shale, silty limestone, limy siltstone, and metavolcanic rock is in fault contact with the melange, and may 10 ! be of the same age. Plafker (oral commun., 1976) considers all these rocks to be part of the Yakutat group. These rocks are 12 intruded by foliated, highly altered granodiorite and diorite of 13 inferred Cretaceous age and by unfoliated lighter-colored granodiorite of inferred Tertiary and(or) Cretaceous age. These 15 rocks are unconformably overlain by at least 3,660 m (12,000 feet) of marine and nonmarine Tertiary clastic and volcanic rocks. The Tertiary sequence is relatively coherent and has been subdivided into three formations (Plafker, 1967, 1971): the Cenotaph Volcanics and the Topsy formation, both 20- post-early Oligocene(?) to pre-middle Miocene age, and the 21 i Yakataga formation of middle Miocene to early Pleistocene age. 22 The Topsy formation and Cenotaph Volcanics may grade into each 23 other and interfinger; both are disconformably overlain by the Yakataga formation. These formations are probable lateral equivalents B-9 9-1267 of units now being evaluated and .to. the northwest- . . _ Fold structures in the pre-Tertiary rocks of the Lituya province are obscure due in part to the lithologies of the rocks, the available control, and the later intense faulting associated with the Fairweather fault. The Tertiary section is also affected by that faulting, and is also folded into two (perhaps separate but on-strike) shallow north-plunging synclines and an asymmetric faulted anticline. The main strand Id- of the Fairweather fault underlies a prominent ice-filled valley for most of its length, but the fault zone extends west into the Lituya province for at least 10 km (6 miles) and is expressed as | 13 both discrete fault strands and intense pervasive shearing. ; | 14 i This fault is part of a high-angle fault system that extends for : 15 hundreds of kilometers from Yakutat Bay south along or near the ; j 16 edge of the continent. The dominant fault movement is inferred | 17 I to be vertical, with the west side down; but both the historical ** 13 record (Tocher and Miller, 1959; Page, 19J) and inferred older movements father south (Loney and others, 1967) suggest a significant right-lateral component. 2! The Lituya province offers the only possibility in the 22 monument for significant modern-day or recent beach placers ! that could contain gold, titanium, iron and platinum. Tertiary 24 rocks are the most likely hosts for oil, gas, and coal. The 25 Mesozoic rocks below the Tertiary section could, by analogy with ___ _ B-10 9-1267 correlative . rocks to the south on Chichagof Island (Loney and others, 1975), be the host for vein-type gold, silver and perhaps base-metal deposits. 10 13 17 B-ll 9-1267 Fairweather province The oldest rocks in the Fairweather province consist of two regionally extensive metamorphic units of unknown, but inferred Precambrian or early Paleozoic, age (Brew, Loney, and others, 1977). Abutting the Fairweather fault is a prominent hornblende schist and gneiss unit that interfingers structurally and probably stratigraphically with a biotite schist and gneiss unit to the east (plate la). This latter unit diminishes in Aprtlv metamorphic grade Aeastward across the province and near the eastern boundary consists of phyllite, graywacke, semischist, and minor metaconglomerate. The hornblende schist and gneiss unit is interpreted by Jones, Silberling, and Newhouse (1978) to be part of their Triassic "Wrangellia" terrane. Berg, Jones, and Richter (1972) interpret all of the western part of the Fairweather province to be party of the [older] Chugach terrane. This contrasts with the interpretation here that all of the Fairweather province belongs to the Alexander terrane (Brew, Loney, and others, 1977; Brew and Morrell, 1978) The eastern boundary of these Fairweather province rocks is the Tarr Inlet suture zone (Brew and Morrell, 1978). Thick layered gabbro complexes (mainly olivine gabbro, gabbronorite, norite and peridotite), also of unknown but inferred Precambrian or early Paleozoic age, intrude the hornblende schist and gneiss unit in a north-trending belt along B-12 9-1267 the axis of the Fairweather Range (fig. A-l). Locally foliated granitic rocks of inferred Tertiary and (or) Cretaceous age, mainly granodiorite and quartz diorite, occur within the belt of gabbros and to the east towards Johns Hopkins Inlet. Bodies of unfoliated granitic rocks, largely granodiorite, granite and tonalite, of inferred mid-Tertiary age form another irregular belt generally to the east of, but to the south overlapping, the gabbro belt. This crude wide belt of granitic rocks also laps over into the Geikie province to the east. The western part of the province is characterized by complicated steep-limbed isoclinal folds; the eastern part by less 12 complex steep- and shallow- limbed folds . 13 Significant faults occur only in the southernmost part of '" the province, where north and north-northeast striking faults offset contacts in a generally right lateral sense. 16 The Fairweather province has the only significant maf ic-ultramaf ic bodies in the monument and' offers the possibility of magmatic copper, nickel, cobalt and perhaps titanium, vanadium, chromium, and iron deposits. It is likely, however, that these would be associated only with the relatively rare ultramafic portions of the layered bodies, and the discovery of new deposits would hinge on identification of such portions in very difficult and inaccessible terrain. The regionally extensive hornblende schist and gneiss unit could host metamorphosed volcanogenic suicide deposits, and the __ B- 13 9-1267 abundant high-level Tertiary granitic plutons and stocks suggest ! the possibility of associated base and precious metal vein i deposits in the country rocks, molybdenum and(or) copper- I porphyry deposits in the bodies themselves, plus late stage ! 5~ ! deposits of tungsten, tin, beryllium, molybdenum, and gold. B-14 9-1267 Geikie province The country rocks of the Geikie province are a diverse 3 J assemblage of hornfelsed pelitic and semipelitic rock, marble, greenstone, and amphibolite (plate la). They are inferred to be 5 largely of middle Paleozoic age on the basis of their probable equivalence to fossiliferous rocks in the Chilkat province to the east. The rocks in the 5" to /2. km-wide Tarr Inlet suture zone, which forms the western boundary jDf_ the province, are very diyers_e__ and are inferred_to_be _Perraian in age on scanty evidence (Brew and _MQrreli,__191I81.._ All oJL these rocks _are _conside_red.part_pf_th_e_____ Alexander _terrane_.______12 The province is dominated by elongate north-trending bodies of highly foliated tonalite and diorite of Cretaceous U age, but the crude belt of unfoliated Tertiary granodiorite, 15 granite, and tonalite that straddles the boundary with the JFairweather province underlies a significant area, particularly to the south. Folds in the Geikie province are difficult to trace and analyze* because the abundant intrusive rocks and extensive faulting have disrupted original continuity. Near the suture zone, the fold orientation and style apparently vary from unit 22 to unit. Northwest-striking faults are recognzied throughout 23 the province and many more probably exist. The two largest are the Brady Glacier fault zone, which lies along the eastern edge B-15 9-1267 of the Tarr Inlet suture zone, and the Glacier Bay fault zone, which extends from Tarr Inlet southeastward into the Chilkat province beneath the waters of Glacier Bay. | i The Geikie province shares with the Fairweather province i the possibility for deposits associated with the high-level Tertiary plutons, and offers limited possibilities for copper, iron, or base metal-bearing skarns and for volcanogenic and stratabound deposits. The Tarr Inlet suture zone and vicinity, particularly where well exposed north of the Brady Glacier /diverse types A 10 of mineralization and has the possibility of gold veins; diseminated copper, molybdenum, and perhaps base metals in AtelvfbdeKotw-oh- por-pky»-y ctepoiftsfi altered zones; and] copper-bearing / . The limited A A amounts of volcanic rock present may constrain the possiblity of volcanogenic sulfide deposits. B-16 9-1267 Chilkat province About 6,100-9,100 m (20,000 - 30,000 feet) of unmetamorphosed upper Silurian through Permian clastic rocks are exposed in the eastern part of the Chilkat province (plate la). i 5 j Graywacke and argillite of Silurian and Devonian age are i ; dominant. They contain discontinuous nonfossiliferous limestones, some of which may be distal equivalents of thick i ; reefoid limestones present in the western part of the province. | The clastic section apparently grades northward into dominantly t volcanic rocks. Fossiliferous carbonate, clastic, and some [ volcanic middle Devonian rocks occur in the north-central and i I northwestern parts of the province. Sparsely fossiliferous i Permian limestone, shale, and volcanic rocks are also present in ; the north-central part. All of these strata belong to the | Alexander terrane. j There are relatively few intrusive bodies in the Chilkat 17 ! province (fig. A-l). A large granodiorite mass of inferred i I Tertiary age occurs in the southwestern corner and several 1 smaller foliated plutons of inferred Cretaceous age are found in ' the northwestern and east-central parts of the province. Small : granitic stocks of inferred Cretaceous age are at the southeastern 22 I corner of the province and a~large~granodiorite and diorite pluton i that has been dated "as Jurassic (160 +~20 m.y.) (Loney and others, 1967) by the lead-alpha method occurs nearby just outside the monument boundary. The small B-17 9-1267 granitic stocks may be the same age. The province also contains locally abundant intermediate and mafic dikes of uncertain age* Large scale recumbent folds are present in the eastern part but have not been recognized elsewhere in the province; it 5 is likely that similar deformation affected most of the province. North and northwest-striking high-angle faults occur throughout the province. Brew, Carlson, and Nutt (1976) suggest 14 km (9 miles) of right-lateral separation on the Excursion Inlet fault (plate la); but the separations on other faults are 10- zone unknown. The Glacier Bay fault/under Glacier Bay proper could be very complex, as the relations of the bedrock units exposed 12 on opposite sides of the Bay are difficult to reconcile (plate la). Richard Couch (written cotmnun., 1975) has suggested that a I 14 presently-active high-angle fault runs from the Grand Pacific t Glacier at the head of Tarr Inlet southeastward beyond the j i southern boundary of the monument; this fault is part of the Glacier Bay fault zone. High-angle faults apparently control .the distribution of Permian rocks in the north-central part of the province, but that area is not well understood. A significant and unusual (because of 20 its orientation) east-west zone of high-angle faults occurs near the northern part of the province. 22 Locally prominant carbonate units near the relatively few exposed plutons and near local dike concentrations offer the 24 possibility of copper, molybdenum, and perhaps base metal deposits in altered zones and skarns as well as gold-bearing______B-18 9-1267 vein deposits. The northeastern part of the province contains the largest concentration of recognizable volcanic rocks in the monument and they and the few other occurrences of volcanic rock suggest the possibility of volcanogenic sulfide deposits. 13 B-19 9-1267 Muir province The Muir province (fig. B-l) is similar to Geikie province in that it is dominated by foliated granitic rocks, mostly of inferred Cretaceous age, the country rocks are hornfelsed 5 Paleozoic clastic rocks with some carbonates. It is like the Chilkat province in that it includes significant amounts of relatively unmetamorphosed Devonian and(or) Silurian volcanic rocks and of Permian clastic, carbonate and volcanic rocks. It differs from both of these provinces and from the rest of the monument because the structural trends are dominantly west-northwest and east-west instead of north-northwest (plate la). In addition to the rocks noted above, minor amounts of 13 both Silurian graywacke and argillite and middle Devonian fossiliferous limestone and volcanic rocks occur in the southern 15 part of the province. Well foliated granodiorite of inferred Cretaceous age 17 dominates the intrusive rocks and occurs in three main bodies (plate la). Locally foliated granodiorite of inferred Tertiary and(or) Cretaceous age forms a large east-west trending body east of the head of Muir Inlet, and stocks of unfoliated porphyritic granodiorite and of andesite, both of inferred 11 Tertiary age occur near the eastern and western ends of the province, respectively. Dikes related to all these bodies and to perhaps younger igneous events are found throughout the B-20 9-1267 province; they are particularly abundant in the large area of hornfels that includes the Nunatak molybdenite deposit. Fold structures in the horafelsed rocks are generally poorly expressed and have not been analysed. The less metamorphosed Permian strata form a north-dipping homocline, or possibly an asymmetric antiform. Several faults have been mapped on the larger nunataks, but extensive glacier cover makes definition of their lengths difficult. The part of the province west and south of Muir Inlet is notable for abundant 10 local shearing, small scale fracturing and retrograde alteration of the granitic and hornfelsed rocks. 12 The Muir province has some high-level Tertiary plutons, 13 abundant local dikes, and extensive sheared and shattered areas in the southern part of the province. It offers the possibility porp^l-y- Uiui po»rfcyH/- ddposlU for/copper^molybdenum " ), base metal veins, and for 16 volcanogenic sulfide deposits in the volcanic rocks present. Extensive snow and ice cover severely limit exposures in the northern part of the province. 22 B-21 Interpretation of the aeromagnetic map of Glacier Bay National Monument, Alaska by Andrew Griscom Aeromagnetic data and interpretation methods The aeromagnetic map of Glacier Bay National Monument was prepared in 1976 at a scale of 1;63,360 from data collected predominantly along northeast-southwest flight lines spaced approximately 1.6 km (1 mile) apart. Because of the great range of topographic relief in this region, the survey was divided into three areas, and each was flown at a different constant altitude above sea level. Most of the monument was flown at an altitude of 2440 m (8000 ft); the Fairweather Range was flown at 4580 m (15,000 ft); and the coastal strip of the Fairweather Range was flown on northwest-southeast traverses at an altitude of 1,510 m (5,000 ft). The three surveys have been mosaiked together to form plate IB at a scale of 1; 125,000. The contour interval is 10 gammas for the survey flown at 2440 m and is 5 and 25 gammas for the other two areas. The local topographic relief both above and below glacial ice is extreme throughout much of this area, particularly in the B-22 9-1267 Fairweather Range and in the mountains of the northeast corner; local relief of 1000 m is common and may exceed 3000 m near Mount Fairweather. Where an area of high relief is composed of magnetic rocks, a local magnetic anomaly is generated by the 5 topography. These magnetic anomalies caused by topography may be superimposed upon even larger magnetic anomalies generated by similar magnetic rocks extending to substantial depths .below the surface. Thus within broad magnetically high areas there may be local magnetic highs and low^over ridges and valleys 10 respectively. Examples of this sort of effect are especially common in the northeast quarter of the aeromagnetic map and a special symbol for these local topographic anomalies is used on 13 the interpretive map (figure B-l). 15 Figure B-l near here 16 The magnetic anomalies and patterns on the aeromagnetic 13 map are caused by variations in the amount of magnetic minerals, commonly magnetite, in the several rock units and are therefore closely related to geologic features. Most, and perhaps all, of the magnetic anomalies in this map area are caused by igneous rocks, plutonic and volcanic, some of which have been | metamorphosed. No known skarn deposits have aeromagnetic expression* 24 The interpretive map (fig. B-l) was compiled by the j following procedure: a preliminary interpretation map was ,' B-23 9-1267 constructed using only the magnetic map and not referring to a geologic map; then the interpretation map was compared with the geologic map and refined by modifying boundaries and interpreted faults; finally, an attempt was made to ascertain the specific rock units causing every anomaly on the map. At these magnetic latitudes, boundaries between outcropping magnetic and relatively nonmagnetic rock units are in general located on the flanks of the magnetic anomaly, approximately at the steepest gradient. The aeromagnetic interpretation map contains many such interpreted boundaries drawn around characteristic anomalies and some of these correspond approximately to mapped geologic contacts shown on the geologic map (plate la). Some of the boundaries, and in particular those which are dashed, represent only approximate outlines of concealed or partly concealed plutons which appear to have crudely domical forms with outward-dipping contacts. For such configurations it is only possible to draw generalized boundaries, if the attitude of the boundary is not specified. Long linear magnetic boundaries, which may truncate other magnetic lineaments, are interpreted as faults and are so indicated on the interpretation map. B-24 Aeroraagnetic Interpretation Symbols Fault inferred from aeromagnetic data Boundary between magnetic and less magnetic rocks Location approximate. Dashed where covered. 0 ° ° o o Axis of magnetic low caused at least in part by a linear topographic low. Symbols indicating the rock unit believed to cause individual aeromagnetic anomalies. Each symbol is located at top of magnetic KljVt or at b-ottam of magnetic low.. Symbols corresponding to units.on the geologic map Tg Unfoliated felsic granitic rocks (Tertiary.) Kg Foliated granitic rocks (Cretaceous) « gb Layered gabbro complexes (Unknown age) Pvg Amygdaloidal volcanic rock and greenstone (Permian) DSvg Greenstone and other raetavolcanic rocks (Silurian and Devonian) mg Hornblende schist and gneiss (Unknown age) Other symbols corresponding to rock units g£ Concealed granitic rocks, probably of Cretaceous age sed Paleozoic layered rocks, predominantly sedimentary A Unidentified magnetic rock unit at or near the surface Topo Magnetic anomaly exaggerated by relatively high-altitude magnetic rocks. Figure B-1. Interpretation of aeromagnetic map of Glacier Bay National Monument, Alaska (Part one of three). B-25 9-1257 138° r~" i.V.'.'.r'T"V" Grand...Pocjfic ^ "O.-f ^.. ..-..- ' -< 10- 88° 3C* 15' h Figure B-1. Continued (two of three). B-26 9-1267 - 39° 00' 17 58" 30 Figure B-1. Continued (three of three). B-27 9. '257 Many of the magnetic lows on the aeromagnetic map are associated with nonmagnetic sedimentary or igneous rocks. Some of these magnetic lows and other lows located within areas of magnetic granitic rocks are on the north side of magnetic rock masses and are the result of edge effects of the magnetic mass. Various calculations including depth determinations and simulation of models of certain anomalies were performed and are described below under the appropriate sections on specific rock units. B-28 9-126? Magnetic properties of rocks In order to interpret the aeromagnetic map it is useful to know the magnetic properties of the rock units causing the magnetic anomalies. There are two such properties to be considered. The first is the magnetic susceptibility which when multiplied by the intensity of the earth's magnetic field (here approximately 0.57 oersteds) gives the induced magnetization of the rock. The second property is the remanent magnetization which is the permanent magnetization of the rock sample and is independent of the present magnetic field of the earth. The relative importance of the two magnetic properties is expressed by the Konigsberger ratio (Q) which is the remanent magnetization divided by the induced magnetization. As described below, the Q of rocks from the Glacier Bay area is 15- generally much less than unity so that the induced magnetization is by far the most important magnetic property. During field work in the summer of 1976 rock samples were collected for physical properties measurements. Other samples were made available from the collection of D. A. Brew for similar measurements. C. S. Gromm£ has kindly provided magnetic properties for samples collected from the gabbro bodies of Astrolabe Point and Mount La Perouse. The results of all of these measurements are summarized in table B-l and are separated into two general B-29 9-1267 Table B-l near here groups of rocks depending on the side of the major magnetic boundary (fig. B-l) from which they came. These results are discussed more fully in subsequent sections dealing with individual rock units. B-30 Table B-l. Magnetic properties of rocks from Glacier Bay National Monument, Alaska. Explanation of table headings in text. Average Average remanent NO. Of . iisceptibility Standard No. of magnetization Standard Average Rock unit samples 2mu/cm3xlO~3 deviation samples emu/cm3xlO deviation Q I. Samples east of magnetic boundary A. Unfoliated felsic granitic rocks (Tertiary) 3 2.25 0.71 - B. Foliated granitic rocks (Cretaceous) 42 2.38 1.13 14 0.36 0.31 0.18 II. Samples west of magnetic boundary A. Unfoliated felsic granitic rocks (Tertiary) 4 0.034 0.009 - B. Foliated granitic rocks (Cretaceous) 1. East of Fairweather Fault 6 0.24 0.22 - 2. West of Fairweather Fault 5 0.077 0.095 td u> C. Layered gabbro complexes (Unknown age) 1. Astrolabe Point 57 3.74 3.99 57 1.50 1.89 0.71 2. Mount La Perouse area 37 0.056 0.045 37 0.061 0.172 1.9 D. Biotite schist and gneiss (Unknown age) 8 0.043 0.007 - E. Hornblende schist and gneiss (Unknown age) 1. From flanks of magnetic high . 14 0.082 0.097 - 2. From crest of magnetic high ' 3 3.82 4.27 - Data provided by S. Groirane 9-»267 General interpretation of the aeromagnatic map The aeromagnetic map displays several areas with characteristic patterns. The east half of the map is composed of closely-spaced broad subcircular magnetic highs which 5 indicate that most of the rocks in this area are magnetic. Correlation of the subcircular anomalies with the geologic map demonstrates that nearly all of the magnetic anomalies are caused by the Cretaceous and Tertiary granitic rocks. A broad magnetic gradient extends from north to south across the center of the map and slopes down to the west. The steepest part of this gradient is the location of the "major magnetic boundary" (fig. B-l), marking the western edge of the magnetic granitic rocks. A linear magnetic high 6 km west of and parallel to the boundary is about 40 km long and is caused by an isolated mass of magnetic Cretaceous granitic rocks. The area extending 30 km west of the major magnetic boundary has an extremely smooth magnetic field indicating that the rocks are only weakly magnetic. A series of elliptical magnetic highs caused by gabbro plutons is west of the smooth area. Parallel to and adjacent to the Fairweather fault is a narrow linear high caused by a narrow belt of magnetic hornblende schist and gneiss. Finally, west of the Fairweather fault are a series of linear magnetic highs which correlate with outcrops of foliated B-32 9-1167 I i 1 | Cretaceous granitic rocks, the exposed and elevated substrate to 2 a coastal belt of non-magnetic Cretaceous and Tertiary U 16 B-33 9-1267 Intrusive Rocks Layered gabbro complexes A row of four gabbro complexes extends from north to south 5 down the west portion of the area. The northern co^le-^. -at MeovCt Fairweather has evident magnetic expression and the anomaly appears to extend south of the exposed area of gabbro to two large local anomalies (labeled "A" on fig. B-l) whose cause is not evident. These two local anomalies are close to major peaks are are in part caused by topography; but some of the rocks in those peaks are probably magnetic. However, these rocks, hornblende schist and granitic rocks, in general have no magnetic expression in this area of the map and the writer prefers to consider the source of these anomalies as unidentified The association of these anomalies with the olae caused by the gabbro of Mount Fairweather suggests that the anomalies may also in part be caused by gabbroic rocks, possibly concealed at shallow depth. A weak broad magnetic anomaly near Mount Crillon is believed to be caused by the northern portion of the Mount La Perouse complex and an associated complex located 3 km north of the La Perouse body. These rocks must be only very weakly magnetic because of the low amplitude B-34 9-1257 of the anomaly. South of Mount Crillon the La Perouse complex becomes nearly non-magnetic in the southern two-thirds of the exposures. There is here no evident magnetic expression at all and sample measurements (table B-l) confirm the very weak magnetic properties. These properties are of interest relative e^st to the nickel-bearing sulfide deposit near the south£as^§ contact of the La Perouse complex and indicate that the sulfide-bearing gabbro complexes may be the non-magnetic ones. The southern complex is located north of Astrolabe Point and has a well-defined associated magnetic anomaly. A calculated model simulating this anomaly (A-A' on fig. B-2) indicates that the contacts of the magnetic rock mass dip Figure B-2 near here outward and that the vertical extent of the body may be as great as 3 km. The computed magnetization for the model is approximately two-thirds that for the measured rock samples (table B-l) but much of this discrepancy has been caused by the simplifying assumption that the model is two-dimensional; that is, it extends to infinity in a direction at right angles to the profile. The southern extension of the Astrolabe Point magnetic anomaly puts an eastern limit on the offshore location of the Fairweather fault which should not intersect the southern end of B-35 RESIDUA L GAMMAS 3OOr 200 fOO 4OOr- 300 CALCULATED 200 FROP) RIDGE I3OO rr. HISH 100- 3oo ->S6200 STOCK OF A;= o.oo/r 8. B-8'. Figure B-2 . Cross-sections of calculated models simulating observed magnetic pro files. Profile A-A crosses the gabbro complex of Astrolabe Peninsula. Profile B-B simulates the magnetic profile across a mountain on the oast side of Glacier Bay north of Beartrack Cove. Location shown on figure B-l. B-36 9-12-57 the magnetic high. This limit forces a slight bend of the fault near a point where it leaves the shore. ID- 17 B-37 9-1267 Foliated granitic rocks The foliated granitic rocks of Cretaceous age display three different kinds of magnetic expression depending upon location. East of the major magnetic boundary these rocks are 5 all intensely magnetic, exhibiting large subcircular magnetic anomalies and substantial magnetic susceptibilities (table B-l). In the central area between the major magnetic boundary and the Fairweather fault these rocks are weakly magnetic (table B-l) except for those causing the linear magnetic high 3 km west of the boundary. West of the Fairweather fault the foliated granitic rocks are still weakly magnetic (table B-l), but the surveying aircraft flew relatively close to the gound and the surrounding Cretaceous and Tertiary sedimentary rocks are non-magnetic. As a result there are linear magnetic highs observed over the elevated granitic rocks. Certain magnetic anomalies over areas of sedimentary rocks 17 in the southeastern part of the monument are interpreted to be caused by concealed granites (g on fig. B-l), either because of the form of the anomaly or because the anomaly appears to be associated with an adjacent anomaly known to be caused by granitic rocks. Significant characteristics of all these subcircular anomalies are the substantial width of the magnetic gradients on the anomaly flanks and the common absence of a nearby magnetic low on the north side of the anomaly. These two B-38 characteristics indicate outward-dipping contacts for the intrusions. Boundaries for plutons of such shape can only be approximated if the rocks are not exposed. The three most intense circular anomalies east of the major magnetic boundary occur near relatively isolated summits where foliated granitic rocks are exposed at altitudes of 1300 to 1600 m (4000 to 5000 ft). Calculations on profile B-B' (fig. B-2) indicate that these anomalies are more intense because of a topographic effect, amounting to about 130 gammas if the magnetic rocks extend to an altitude of 1000 m. A mountain ridge 1300 m (4000 ft) high with a base 6 km wide at sea level (fig. B-2) will cause an anomaly of about 200 gammas at the flight height of this survey, using the magnetic properties of table B-l). The 200 gammas represents the contribution to the total anomaly amplitude caused by the topographic effect and, if removed, will leave an anomaly comparable in amplitude to adjacent anomalies caused by granitic rocks at lower elevations. All of the observed anomalies can thus be explained by the magnetic properties of the rocks and are not indications of mineralization. Large sulfide-bearing altered zones, such as those typical of porphyry-copper deposits may be accompanied by destruction of in magnetite/the altered rocks. If these rocks where fresh contain significant amounts of magnetite, then a mineralized area may appear as a local magnetic low, possib^^ supejrimpos^d_upon_a_____ 8-39 ,-:.-..,.-. .*-. 9-1267 broader magnetic high. Unfortunately topographic effects, such as a deep valley, will also cause local magnetic lows, and there is the added complication that altered rocks may erode out to form topographic lows. Many local magnetic lows are observed over areas of granitic rocks near the northeast corner of the aeromagnetic map. All of these lows appear to be associated with topographic lows that are commonly occupied by glaciers. There is no clear indication of porphyry-copper mineralization in this area on the basis of the aeromagnetic map. 10 The west-sloping magnetic gradient associated with the major magnetic boundary provides an opportunity to calculate the minimum thickness of the magnetic granitic rocks on the east side of the boundary. Model calculations (fig. B-3) were performed to simulate the gradient along profiles C-C' Figure B-3 near here and D-D'. Profile D-D' was taken along a flight line and then projected normal to the gradient before performing the model calculation. The models extend down to about 10 km below sea level and imply that the eastern magnetic granitic rocks form a slab at least this thick. The magnetizations used for profiles C-C' and D-D' were 2.2 x 10"~3 and 1.8 x 10~3 emu/cm3 , respectively. These values are comparable with the measured magnetizations (table B-l) which when added together vectorially B-40 -, 56100 H 200 -\ 800 GRAN/TtC ROCKS /*/= O.OOZ.2. A. Profile. C-C'. i S&Soo -(661 00 -\ 55^)00 B. D-D'. Figure B-3. --Cross-sections of calcu]at-ud morals simulating observed magnetic profiles acr-j.^r, the major magnetic boundary. Profile C-C^ is across tiic south end of tho boundary. Fro^jlo D 0 L is across the central part of the boundary. Location ?Kowei on figsuc 8-1 . B-41 - 9-1267 when added together vectorially give a maximum result of about _o 1.71 x 10 J for the foliated granitic rocks. 10 13 25 B-42 Unfoliated felsic granitic rocks The unfoliated granitic rocks of Tertiary age are less abundant than the foliated Cretaceous granitic rocks but have similar magnetic expression depending on the location. East of the major magnetic boundary the Tertiary granitic plutons without exception are associated with magnetic highs. West of the boundary the Tertiary plutons are very weakly magnetic either occupying magnetic lows or appearing to have no effect on the magnetic map. The physical properties listed in table B-l confirm that the rocks have a large susceptibility east of the boundary and a very small susceptibility west of the boundary. 15 16 B-43 9-1267 Layered Rocks Hornblende schist and gneiss The hornblende schist and gneiss unit is found in a belt about 12 km wide parallel to and on the east side of the Fairweather fault. The unit generally has no magnetic expression and must be only weakly magnetic. A narrow linear magnetic high, parallel to the Fairweather Fault and located about 2 km east of the fault, forms a very striking feature on the magnetic map. This high is evidently caused by a specific magnetic unit within the generally non-magnetic hornblende schist and gneiss. Magnetic properties measurements on rock samples (table B-l) confirm the existence of a narrow magnetic unit located at the crest of the high. It is not known whether 15 this magnetic unit is also a stratigraphic unit; field mapping did not show any lithologic differences. B-44 9-1267 Sedimentary and metasedimentary rocks These rocks are found throughout the aeromagnetic map area and are universally associated with magnetic lows or areas of smooth magnetic field. The rocks are at most weakly magnetic. Samples of biotite schist and gneiss from the area southeast of Astrolab/e Peninsula are very weakly magnetic (table B-l). The isolated patches of sedimentary rocks found within the large area of Cretaceous granitic rocks east of the major magnetic boundary are in magnetic lows and are interpreted to be 10 relatively thin remanents lying upon a more continuous mass of granitic rocks at depth. Model calculations show that a mass of mon-magnetic material 1.6 km thick surrounded by magnetic o granitic rocks (magnetization 0.017 emu/cm ) can cause a local magnetic low ranging in amplitude from 150 to 200 gammas, 5 depending on the attitude of the contacts. The observed magnetic lows associated with patches of sedimentary rocks are rarely larger than 100 gammas and never large than 150 gammas. 18 It is concluded therefore that the isolated patches of non-magnetic sedimentary rocks are in general no more than 20 1.6 km thick, much thinner than their lateral dimensions, and also much thinner than the calculated 10 km thickness of the magnetic granitic rocks. 25- B-45 9-1267 Paleozoic volcanic rocks East of the major magnetic boundary there are two volcanic rock units which cause local anomalies on the aeromagnetic map. These anomalies are outlined by boundaries on the interpretive map (fig. B-l). Of these relatively minor anomalies two are caused by the greenstone and other metavolcanic rocks of of Silurian and Devonian age, one of the anomalies being about 9 km long by 5 km wide. 1 Cl 22 B-46 (p« B-48 follows) 9-1267 Faults Several interpreted faults are shown on the aeromagnetic interpretation map. These faults are permitted by the geophysical data but may not be as extensive or continuous as indicated in figure B-l. The magnetic anomaly at Astrolabe Peninsula places an eastern limit on the offshore extension of the Fairweather fault. The thrust fault shown on the geologic map paralleling the shoreline west of the Fairweather fault does not appear to offset the basement surface because there is no disturbance of the magnetic gradient east of the thrust fault. 13 23 B-48 9-K67 Major Magnetic Boundary The significance of the major magnetic boundary (fig. B-l) is not entirely clear but it is evidently of considerable regional importance. Pertinent facts relating to the boundary are briefly reviewed below. The boundary separates a region of extremely magnetic granitic rocks from a region of very weakly magnetic rocks along a rather straight line. Calculations show that the magnetic rocks are about 10 km thick. Granitic rocks of Cretaceous and Tertiary age are found on both sides of the boundary and are magnetic to the east and non-magnetic to the west. The boundary is parallel to and 4 to 10-km east of the 12 eastern border of the Tarr Inlet suture zone (Brew and Morrell, 1978). This eastern border is shown on the geologic map as the fault extending from Tarr Inlet at the north edge of the map southward under the Lamplugh and Brady Glaciers. As a tentative hypothesis it is suggested that the magnetic properties of the different ages of granitic rocks were determined by the crustal rocks in which the plutons formed or through which the plutons moved upwards. The presence of a suture zone indicates that different crustal rocks were juxtaposed here along a line near to and parallel to the major 22 magnetic boundary. Perhaps these different crusts were the cause of the differing magnetic properties of the granitic rocks on each side of the boundary. These differences may also include B-49 diifferences in mineral deposits associated with the granitic rocks. 5 ID- 15 25 B-50 9-1267 Interpretation of gravity and ice-thickness data by David F. Barnes, Robert L. Morin and Raymond D. Watts Large gravity anomalies within the Glacier Bay Wilderness Study Area suggest that some of the rock units associated with significant mineral deposits may have vertical and(or) horizontal dimensions that locally exceed those indicated by geologic mapping. Gravity measurements in the area began in 1956 and have continued as parts of various geodetic, 10 glaciological, marine and regional studies (Thiel and others, 1958; Rice, 1969; Peterson, 1970; Gumma and others, 1973; Barnes and others, 1975; Barnes, 1977). Surveys made in 1976 were 13 planned to complete the regional coverage of the area and were 14 aided by both helicopter support and radar ice-thickness measurements; the latter provided estimates of the gravitational effect of underlying ice masses where the terrain was so mountainous that landings could only be made on glaciers. However, various problems limited both the number of measurements and the coverage obtained. Good regional gravity coverage of the whole monument may depend on perfection of airborne techniques for both gravity and ice-thickness 22 measurement 24 B-51 9-!S Gravity data Much of the shoreline gravity data were collected by skiff traverses in the 1969 and 1972 field seasons during which the M.V. WATERS served as support vessel (Barnes and others, 1972 and 1975). Additional shore line traverses and most of the helicopter traverses were completed in 1976, using the R.V DON J. MILLER as support vessel. Nearly 500 measurements 10- are now available in the study area and have been incorporated along with some other data (Peterson, D. N., 1970, and Hudson, Travis, personal communication, September 1975) in figure B-4, 13 which does not include some available data from marine surveys. 15- Figure B-4 near here 16 I 17 Datum control for the gravity surveys was established by the southeastern Alaska gravity base station network (Barnes, 1972), which has been adjusted to the International Gravity Standardization Net - "IGSN 71" (Morelli and others, 1974). The principal base for the surveys was at Bartlett Cove on the 22 i concrete platform of the fuel pump house and above the bronze Reference Mark 2 of USC&GS triangulaton station "PARK", where the established gravity is 981,770.15 mgal on the 1971 datum. Additional recoverable bases we re established at temporary_____ B-52 9-1267 operating centers which are shown in figure B-4; descriptions and observed gravities of these stations may be obtained from the U.S. Geological Survey. Elevation control for the shoreline data was obtained from sea level corrected for tidal variations; and altimetry was used for most of the land measurements, where the calculated anomalies may thus have a much greater uncertainty of perhaps + 5 mgals. The reduction density was 9 ! 2760 kg/m , which was obtained from measurements discussed in ID- the next section; and the latitude correction was obtained from the 1967 Geodetic Reference System. The data have been partly corrected for the effects of nearby terrain (to a radius of 25 km) by a computer program (Plouff, 1977) which uses mean elevations estimated by eye for compartments with dimensions of 1 minute of latitude by 2 minutes of longitude. In the area between Mount La Perouse and Lituya Bay, where both the number of stations and steepness of terrain are large, compartments of half this size were used. At most land stations the accuracy of the terrain corrections is probably good in comparison with the accuracy of elevation corrections obtained from altimetry. However, a few measurements were made on snow domes and cornices, where the computer-calculated anomalies may be a few milligals low, but where measurements necessary for accurate inner-zone corrections could not be safely obtained. Even larger uncertainties were encountered in using some of the radar B-53 ------/X' ^UN* »;«t«rir } / * \ «/ ftI jC 9-1267 ice-thickness measurements to estimate the effects of underlying ice, where various assumptions concerning the under-ice topography can produce corrections varying through a range of 40 mgals for some of the ice thicknesses encountered. iO 12 15- 22 B-56 9-1207 | . Density data ^ * i \ Density measurements were made on about 175 hand specimens 4 j 1 by standard techniques of weighing in air and water. The ^_ i specimens measured were selected in three different groups: 6 i 1) nearly 100 samples collected for magnetic and other physical 7 ; property measurements during the 1976 geophysical surveys; i 3 ; 2) 30 to 40 samples from the geologists' collections selected to 9 I ! represent the principal rock groups on the generalized geologic i ~I map; 3) 30 to 40 samples from specific rock units which are \ ~, i 1 associated with the larger gravity anomalies. The distribution ; of the density data is therefore somewhat uneven, and the 13 ! j classification of the rock units reflects the varying objectives I of the sampling. The density data are summarized in figure B-5, '~~ ' and the crosses in figure B-4 show the localities where the i Figure B-5 near here ;s ' measured specimens were collected. Both the density data and the gravity map suggest that only a few rock units in the study area are responsible for the larger gravity anomalies; the Tertiary sedimentary and intrusive rocks have slightly low mean densities, and the layered gabbros and high-grade garnet gneisses have significantly high mean B-57 GENERALIZED ROCK UNIT TYPES NUMBIR DENSITY IN KILOGRAMS PER CUBIC METER OF AGE LITHOLOGIES SAMPLES 2600 2800 3000 3200 3400 UNITS T F I T T T * y T ] Lower-density rock units Tertiary Sediments & volcanics 12 1 0 j Ty.Ttc Tertiary Granitic infcrusives 9 I 0 i Tg Medium-density rock units I Q J Cretaceous & Tertiary Granitic intrusives 63 i v * Kg.TKg 6' Cretaceous Sedimentary rocks I 0 I Permian Phyllites & greenstones 7 I 0 I Pap,Pdm,Pvg Silurian & Devonian Sedimentary & volcanic rocks 11 i e i OSsg.DSvg.DSc Ul 00 Paleozoic Lower grade metamorphic rocks 8 I 0 I Pzh.Pzm unknown (Pre-Cambrian?) Phyllites & gneisses 7 i 0 i mgp unknown (Pre-Cambrian?) Schists & gneisses 16 i 0 i ms.mg Higher-density rock units - Paleozoic High-grade (garnet) gneisses 22 i 0 i unknown (Pre-Cambrian?) Layered gabbros *. 26 * = e i gb ii _ i _ i _ i _ i _ i _ i i i i 2600 2800 3000 3200 34C)0 Lines show range of measured densities. Circles show mean for each rock group. FIGURE B-S BAR GRAPH OF HAND-SPECIMEN ROCK DENSITIES 9-1267 densities. The remaining Mesozoic, Paleozoic and Pre-4~ambrian(?) sedimentary, intrusive and metamorphic rock units all have mean densities that range between 2720 kg/m q and 2820 kg/m q . The mean density for all of these rock units that do not produce large anomalies is 2760 kg/m q , which is significantly higher than the typical continental-rock 2670 kg/m q mean density used in the reduction of gravity data for most regional maps including the Alaska gravity map (Barnes, 1977). The higher mean density (2760 kg/m q ) was used for 10 reduction of the data for this map of the study area but earlier gravity maps of the same area have used the lower standard 12 density. Although the mean densities of most of the Mesozoic to j/ Pre-*cambrian(?) rock units are similar, figure B-5 does suggest that the densities of these rock units increase slightly with age and metamorphic grade. Small gravity anomalies are probably associated with some outcrops of these slightly older and higher grade rock units, but most of these anomalies seem to be sufficiently subtle to be masked by steeper gradients associated with the larger anomalies and regional fields. The rocks with the highest degree of metamorphism in the 21 study area are also its densest rocks and cause a significant broad gravity high in the south-central part of the area near 23 Dundas Bay. The specimens of these foliated hornblende-quartz- 24 feldspar gneisses with significant amounts of garnet varied B-59 9-1267 . -3 widely in hand-specimen density but averaged over 3000 kg/m . The other dense rock group in the study area consists of the layered gabbros of the Astrolabe, Crillon-La Perouse, Mount Wilbur, and Mount Fairweather complexes. The densities measured for specimens of these rocks also varied widely but o average slightly less than 3000 kg/m . The associated gravity anomalies are large and suggest thickness greater than a few kilometers. Most of the specimens measured were the gabbro cores used for the paleomagnetic studies; and such rocks could 10 constitute too selective a sampling of the rock unit. Only the Tertiary rock units have low enough mean densities to cause significant gravity lows, but the number of 13 samples measured may be too small to provide accurate mean densities because the density variation is large. The Tertiary o felsic intrusives have a mean density of 2690 kg/m which is high in comparison with most continental rocks but low enough to cause small negative anomalies in this area, where denser rocks predominate. In figure B-5 an even larger density variation is indicated for the Tertiary sedimentary rocks, but the mean density is strongly influenced by the high density of one phyllitic specimen which may have been metamorphosed by nearby volcanic rocks. If this specimen is ignored, the mean density -5 is close to 2590 kg/m , a value that resembles measurements made on similar rocks in other parts of the Gulf of Alaska (D. F. Barnes , unpublished data) . Furthermore, B-60 sedimentary rocks are present but are difficult to sample and measure. The mean density of the entire Tertiary stratigraphic section may thus be significantly lower. '5 9-12S7 Description and interpretation of the gravity field Figure B-4 shows that the gravity field of the study area can be separated into two principal parts with contrasting anomaly patterns. One part is a belt of high amplitude anomalies in the western part of the area that almost parallels the Gulf of Alaska coastline and the other part is a zone of gentle gradients in which the gravity field decreases gradually 9 i but irregularly towards the northern and eastern part of the area. The boundary between these two anomaly patterns extends from lower Johns Hopkins Glacier to the western corner of the entrance to Glacier Bay. This gravitational boundary is thus 13 oblique to and largely west of both the geologic boundary described as the Tarr Inlet suture zone and the magnetic boundary that is parallel to and east of that zone. However, the gravitational contours are strongly influenced by both crustal thickness and local high-grade metamorphism, which may deflect both the northern and southern ends of the boundary, respectively. Adjustment for such deflecting factors could rotate the gravitational boundary so that it would be parallel to but west of the geologic and magnetic boundaries. The gravitational patterns probably reflect deep features which are not obvious in the exposed geology and which do not influence the magnetic field. B-62 9-1267 The zone of gentle gradients contains no large closed anomalies or large deflections of the gravity contours within the study area* Figure B-4 does, however, show two closed anomalies just outside the monument. A large closed high in the northeast corner of the map is associated with the Haines gabbro body, and a smaller closed high south of Gustavus also shows on the magnetic map and is probably a mafic intrusion. Except for these features, the gravity field within the zone of gentle gradients resembles that in the remainder of southeastern Alaska with the important exception that the contours in the northern part of the map have a pronounced east-west trend. In much of the remainder of southeastern Alaska (Barnes, 1977) the gravity contours are similarly spaced and depict a field that decreases gradually from high anomalies near the coastline to a low near the International Boundary. This decrease is believed to 16 represent an increase of crustal thickness from about 15 km at the continental margin to about 45 km near the Canadian border. In the study area the anomaly change is smaller and the crustal thickness probably increases only to about 35 to 40 km. The east-west trend of these contours in the study area is of some interest. Throughout the remainder of southeastern Alaska the - 40 to -70 contours all trend northwest parallel to the International Boundary, but near Lynn Canal these contours bend sharply westward. The topographic axis of the Takhinsha Mountains along the north edge of the study area is also east- B-63 9-1267 west and the gravity contours probably represent crustal thickening beneath these mountains. The belt of high-amplitude anomalies in the western part of the study area is dominated by a gravity high along the axis of the Fairweather Range, but between this feature and the zone of gentle gradients are some smaller anomalies that deserve discussion. Near Dundas Bay, at the south edge of the map,, is a small gravity high which includes Bouguer anomalies higher than 4-30 mgals. The highest anomalies were measured in the West Arm 10 of Dundas Bay and on the nearby shoreline of Icy Strait" , both of which are in the most highly metamorphosed and densest rocks found in the study area. Figure B-5 shows that these high-grade garnet-rich gneisses, schists, amphibolites, and metavolcanics < of early Paleozoic age (part in the Pzg map unit) have a mean o o 15 density of 3020 kg/m , about 0.26 kg/m higher than the mean 16 density of the surrounding rocks. The 4-20 mgal contour approximately outlines the outcrop area, but the +10 contour outlines a broader area that includes several outcrops of Cretaceous granite and other rocks. The broader anomaly is interpreted as evidence of higher grade metamorphic rocks which may locally underlie some of the granites. Calculations based on the simple assumptions of an infinite slab suggest that the total thickness of the higher grade rocks probably exceeds 2 km. If they represent a deep roof pendant surrounded by granite this might also explain the higher grade of metamorphism. The B-64 J-1267 anomaly extends southward across the Inian Islands in Icy Strait and onto the northern shore of Chichagof Island, where higher gravity values were measured along portions of Idaho Inlet. Geolgically, these higher grade metamorphic rocks belong in the 5 Geikie province, so the anomaly should perhaps not be considered part of the belt of high amplitude anomalies that seems to form the western part of the Glacier Bay gravity field. Rocks of the same unit occur north of the Geikie Inlet, where their metamorphic grade is lower and where their influence on the gravity field is smaller. The zero-milligal contour on the east side of the gravity . high caused by the Dundas Bay metamorphic rocks might be considered the extreme limit of the anomaly. However, this contour closely parallels the west edge of an area of Tertiary granitic rock and is believed to be controlled by these intrusives. The anomaly associated with these rocks is so small that its eastern boundary is obscured by the regional gradient, and its amplitude cannot be estimated from available data. Similarly on the west side of the metamorphic high a strip of low gravity bordered by 4-10 mGal contours extends southward along the west side of Brady Glacier and Taylor Bay. This gravity low is also associated with outcrops of the Tertiary granites. Tertiary granites also extend northward and probably cause some of the low gravity measured along the west side of Brady Glacier. Data in this area are, however, very scarce, and B-65 9-1267 there are not enough stations to isolate a local low from the regional decrease in gravity. Figure B-5 shows that the mean density of the Tertiary intrusive rocks is only slightly lower than that on most of the rocks in the study area. The gradients associated with the high-grade metamorphic rock and the Tertiary intrusives are both small in comparison with the much larger gravity features that dominate the belt of high amplitude anomalies: namely a gravity high along the belt 9 I of ultramafic rocks which forms the axis of the Fairweather 10 | Range and an adjacent gravity decrease westward towards the 11 I coastal Tertiary section. These two anomalies are separated by 12 I such a short distance that each affects the quantitative i 13 ! interpretation of the other. The Bouguer anomalies along the 14 I trend of the Fairweather Range locally exceed 4-50 mGal, values ' 5 ' which are extremely unusual for mountains with peaks having i6 I elevations of 4 to 5 km, where anomalies below -100 mgals might > 7 ; be expected. The isostatic anomalies in the Fairweather Range 3 are extremely high and are probably exceeded at only a few ? places in the world such as the Santa Marta Mountains of .'o~ Columbia (Case and MacDonald, 1973). Where such anomalies do exist they are generally associated with one or more bordering ~2 , gravity lows, such as occurs in the study area, but the tectonic 23 i relationship between the highs and lows is often uncertain. ? Virtually all of the gravity measurements in the higher 2j parts of the Fairweather Range produce high Bouguer anomalies 9-1267 even though some are not close to mapped outcrops of gabbro. These values suggest that the gabbro probably underlies a larger proportion of the mountain range than is indicated by geologic mapping, and that it may underlie most of the length of the range as outlined by the +30 mGal contours in figure B-4. However, the measurements are really too few and not well enough distributed to prove such a conclusion, although none of the data contradict it. For example, the gravity data are contoured as though the Astrolabe-De Langle and Crillon-La Perouse gabbro 10 bodies are connected at depth even though the two intrusions have different compositions and magnetic properties. The lack of any gravity measurements on Mount Marchainville makes such contouring questionable, but a single measurement on a glacier 14 1 east of the mountain tends to support the contouring. 13 Most of the Fairweather Range gravity data are concentrated in the vicinity of Mounts La Perouse, Dagelet and Bertha. Here the center of the belt of contours that marks the east side of the anomaly is 1 to 3 km east of the gabbro outcrop and suggests that this may be the true edge of the outcrop, but here the effects of the Fairweather fault and nearby Tertiary section also tend to shift the gradient seaward. Thus preliminary inspection of the gravity anomaly suggests that the gabbro complex is both longer and wider than its outcrop. The combined gravity and density data provide some information concerning the vertical._form _o_f_Jthe gabbro______B-67 c«.i-K-«*.. :.-i 7-1367 intrusion, but the analysis is not conclusive and is complicated by uncertainties in the data and in necessary assumptions. Figure B-5 shows that the mean density of the gabbro is about o 240 kg/m higher than that of the surrounding rocks, and the map suggests a total Bouguer anomaly of about 45 mGal for the intrusion. These two figures can be used in an infinite-slab approximation to estimate that the gabbro has a total depth of more than 5 km. Simple two-dimensional model studies tend to increase this thickness to about 6.5 km and suggest that the sides of the intrusion are close to vertical. However, these calculations assume a regional field that is nearly flat but increasing slightly (less than 0.2 mgal/km) toward the ocean. This regional gradient cannot be accurately estimated because the gravity anomaly at the coastline on the western side of the map is known to be strongly influenced, but to an unknown extent, by the presence of underlying Tertiary sedimentary rocks. The gravity low associated with the Tertiary sedimentary rocks is another very large anomaly that is difficult to analyze. At Lituya Bay the Bouguer anomaly decreases about 50 mgal between the mountain front (Fairweather fault) and the seacoast. The discussion of figure B-5 suggested that reasonable density for these Tertiary sedimentary rocks might be o about 2,590 kg/m or lower, which would suggest a density o contrast of about 170 kg/nr or more. From these data infinite- B-68 9-1267 slab calculations indicate that the Tertiary section is about 5 km thick at the coastline. This figure is too high, so the low-density portion of the Tertiary section may not have been adequately sampled. Seismic data from offshore (Plafker and others, 1975) indicate a probable thickness between 2 and 3 km, although the sedimentary velocity is as poorly known as the density. 13 15 22 B-69 9-1267 Ice-thickness measurements The ice-thickness measurements were made primarily to support the regional gravity coverage and used the technique for radio-echo sounding of glaciers described by Watts and England (1976). The initial measurements were made on Finger, La Perouse, Crillon, Desolation, and Fairweather glaciers, which are valley glaciers flowing westward from the higher mountain summits towards the Gulf of Alaska. The measured ice 10 thicknesses ranged from 100 m on their lower ice tongues to as much as 450 m in their upper cirques, and thicknesses of 200 to 300 m were typical of most valley portions of the glaciers* These measurements are summarized in table B-2. 15 Table B-2 near here The Brady Glacier is the largest in the monument and drains much of the eastern flank of Mounts La Perouse and Bertha. Its upper icefield is the accumulation area for several smaller glaciers as well, including Reid Glacier, which flows northward into Reid Inlet on upper Glacier Bay. Figure B-6 shows a contour map of the surface of Brady Glacier and the locations and magnitudes of the seven ice-thickness measurements that were made on it and its tributaries. *%-Z. U»S. Geological Survey ; 1976 Ice Thickness Measurements in Glacier Bay^Konutnent r Ice Gravity Elev Thickness Glacier Station Latitude Longitude m m La Pe rouse GA88 58°29.45 137*16.68 195 99/191 On Lower tongue ti GA90 58°30.65 137*13.75 370 174 NW of South Dome ti GB27 58*35.14 137°10.40 1915 214 S. of Mt. Dagclet tt GB35 58°33.60 137°06.60 2255 442 Cirque S. of Mt. LaPe rouse it - GB33 58*35,60 137°06.80 2440 408/402 Saddle E. of Mt. Dagelet Finger GA95 58°30.10 137 "07. 00 ,785' 207 At Junction of N. Branch it GB37 5B°31.88 137°06.80 1925 273 Central Cirque on N. side ti GB30 53*29.45 137°02.1Q 1940 239 Saddle on S. side it GB36 58"32.20 137*04.90 1980 228 Northwest upper Cirque Crillon GB17 58*37.48 137*24.35 380 358 . Near Center in Desolation Va S. Crillon GB16 58°37.38 137*21.42 670 207 C*nt*r of lower glacier S, CrUl«» GB12 58*37.79 137°10.6S 895 337 Middle of glacier Desolation GB19 58°47.45 137°31.40 1095 303 Northeast Cirque Fainreather GB24 58°50.65 137°44.60 '400 369 W. of Desolation Valley GB21. 58°51.90 137°26.82 1820 170/496 NW of MC . Salisbury GB22 58°51.97 137°38.90 1890 273 Cirque SE of Mt. Fairweatter Brady GC35 58°33..r>0 136°45.40 660 910 SW of Mt. Divide it GC30 58°30.20 136°46.80 765 948 SE of Aurora Glacier GC36 58°35.35 136*57.30 990 1022 Center of W arm E .of Mt. LaPerouse GC40 58°36.20. 136*56.60 1000 201 Ice rise N of Nunatak GC39 58°34.38 136°59.95 1160 254 Cirque E of Mt. LaPerouse GB32 5S°36.38 137°03.30 1280 235 Cirque SE of Mt. Crillon GB31 58°39.05 137*02.35 1480 222/229 Cirque S of Mt. Bertha B-71 9-1267 Figure B-^ near here JO- U 15 18 B-72 13T MT. - -( 5 DIVIDE'j~a ...... F...... ;:::::: A ...... APP30X. SCALE 1: 220 000 [:[':': \ TAYLOR B-73 9-1267 The ice-surface contours and the several nunataks suggest a complex and rugged sub-ice topography which was confirmed by the radio soundings. The two measurements near the main axis of the glacier (950 m and 910 m) both indicate a basement depth of 5- ! about 200 meters below sea level. Presumably, the glacier fills a deep fiord and the western shore of Glacier Bay would be part of an island if the glacier, its outwash fan, and its terminal moraine were removed. On the western arm of Brady Glacier, about 200 km east of the shoulder of Mount La Perouse, measurements indicated an ice thickness of 1020 m and suggested the bottom of the glacier is 12 below sea level. The contrast between this below-sealevel elevation and the 300 m summit of the mountain indicates very 14 rugged topographic relief. Furthermore, the probable directions 15 of ice motion may be inferred from the ice surface contours and | 15 i from crevasse patterns, and these approximate flow directions I i- I are shown by arrows on the map. The arrow nearest to this i 13 I ice-thickness measurement indicates a probable southeastward 19 ; motion of the glacier and suggests that a deep fiord may follow i 20 the approximate direction of this arrow. Such a fiord could 21 | underlie the ice on the north side of the small nunataks where i i 22 ! the Brady Glacier nickel-copper prospect crops out (plate 3). i 23 I This mineralized prospect has been extensively drilled, but the :* i proximity of a deep nearby glacier could restrict the deposit's 25 i dimensions. However, the actual ice-thickness measurements are i______' B-74 9-1267 about 5 km from the deposit. 5 10- 12 15 20 22 23 25 B-75 Geochemistry By Brace R. Johnson and Donald Grybeck Introduction Geochemical studies by the Geological Survey in Glacier Bay National Monument included sampling both bedrock and active-stream sediments. The bedrock sampling program provided information on the normal or "background" abundance of the elements in each rock unit and also on the concentration of metallic elements in altered or mineralized zones. The bedrock data were also used to aid in interpretation of stream sediment data. The stream-sediment sampling program was designed ,to identify drainages or areas with anomalously high concentrations of one or more elements. The anomalous samples serve as indicators of previously unidentified mineralization or can be related to known mineralization. Stream-sediment samples were usually collected prior to geologic mapping with the aid of a helicopter in inland areas and with small boats along shorelines. During the coastal sampling, clay-sized or silt-sized material was collected from active stream channels above the highest high-tide level whenever possible. Clay-or silt-sized material was difficult to obtain from streams with steep gradients or adjacent to glaciers and some samples consisted mostly of sand-sized and larger material. Each sample was dried and screened and the minus 80-mesh fraction was analyzed. B-76 Stream-sediment samples reflect differing weathering conditions and modes of metallic element transport. Most samples collected below timber- line had a moderate organic content and a high clay-size material content although organic-free material was sought. In these samples, the metals are probably largely scavenged from solution by chemical action onto clays and iron oxides. However/ samples from streams above timberline or adjacent to glaciers/ even when composed of clay- or silt-sized material/ probably consist largely of mechanically broken rock material and chemical solution and deposition is probably minor. Some of the major rivers flowing below timberline, the Dixon River for example are also depositing fine sediments by the settling of glacial flour. Because of these vari abilities as well as analytical variations/ single anomalous stream- sediment samples were not considered as reliable indicators of possible mineralized bedrock as were clusters of samples with anomalous values. The stream-sediment samples used in this study include samples collected in 1975 and 1976/ as well as samples collected in 1966 as part of an earlier U.S.G.S. program (MacKevett and others, 1971). Duplicate samples were collected at all stream sediment sites to compensate for the analytical variation found in a similar program in the Tracy Arm- Fords Terror area to the southeast (Johnson and others, 1977). The 1966 analyses were not completely compatible with the 1975 and 1976 analyses due primarily to changes in analytical techniques and detection limits for some elements. To fill in areas of incomplete coverage in the 1975-76 B-77 work/ 714 samples collected in 1966 were reanalyzed using current techniques. Prior to statistical analysis of the data, analytical results for each stream-sediment site were averaged. Therefore, approximately 700 of the 1300 site values are based on single samples while the remaining 600 are based on duplicate samples. A bedrock sample (or samples) was collected for geochemical analysis at each geologic station. The number of these samples varies areally depending on access and the type of geologic mapping. In general, at least one sample was collected per square kilometer of outcrop in the western third of the Monument. However, the sample density thins rapidly to the east averaging approximately one station per 50 square kilometers along the eastern boundary. Each rock type present at each station was sampled and particular care was taken to sample all rocks with visible alteration, staining, or ore minerals. For this reason, the total bedrock sample population is considered biased toward samples, high in metals of economic interest. These samples were not removed from the total rock population and the background levels determined by subsequent statistical analyses may be slightly high. Mineralized bedrock samples collected in 1966 were not included in the present study. B-78 Analytical support All geochemical samples were analyzed spectrographically for 30 elements by the U.S.G.S. Branch of Exploration Research with the standard Geological Survey semiquantitative techniques and for gold/ copper, lead, mercury, and zinc by atomic absorption spectroscopy. Most samples were routinely scanned for radioactivity with a scintillation counter in the field. Because of Numerous scintillation counter failures and the uniformly low readings, 65 samples were analysed for uranium by wet-chemical methods. The sensitivity for each element using the various techniques is included in the appropriate figures. The accuracy and precision of the sampling-sample preparation- analysis process are difficult to determine. The accuracy, if not precision, of atomic absorption spectroscopy and wet-chemical analysis is such that errors are generally inconsequential compared with the problem of obtaining chemically homogeneous replicate samples at one sample site. The semiquantitative spectrographic analyses are subject to more variability. The values are presented by giving the nearest midpoint in a six-step series that uses 1, 1.5, 2, 3, 5, 1, 10..... as the midpoints of the intervals. In a comprehensive study of the precision of the spectrographic method, Motooka and Grimes (1976) showed deviations in replicate analyses of up to two intervals away from the preferred value. In a study of stream-sediment samples collected in the Tracy Arm area, Johnson and others (1977) reported 95 percent of B-79 the spectrographic analyses were within 1.5 to 3.5 intervals of the true value depending on the element. Samples that were rerun during the course of this study occasionally deviated more than one interval from the previous value, but the majority remained within one interval upon reanalysis. Metal values are reported in parts per million (ppm) throughout this report, except for spectrographic analyses of Fe, Mg, Ca, and Ti, which are reported in precent. Where especially high values are dis cussed in the text, the values in ppm may be followed with percent in parenthese (%). For convenience, table B-3 provides conversion between ppm, percent, and ounces per ton. B-80 TABLE B-3 NEAR HERE Nearly 4,000 samples collected by Geological Survey parties were processed and analyseid: 1895 stream-sediment samples and 1873 bedrock samples. In addition 65 of these samples were analysed for uranium. }** All Survey sample locations in the Monument are shown on plate 2, but because of the large amount of data only samples which are anomalous in one or more elements are identified on the plate and listed specifically in this publication. The analytical results for these samples and the descriptive data were stored on , the Geological Survey, Denver, Colorado, Honeywell Multics computer installa tion using the RASS II programs. Complete analytical results for all geochemical samples are available through National Technical Information Service (Forn and others, 1978). B-81 Table B-3 Conversion of parts per million to percent and to troy ounces per ton and vice versa [Conversion factors: 1 Ib avoirdupois « 14,583 ounces troy; 1 ppm = 0.0001 per cents 1 gram per metric ton; 1 ooince per ton (Au or Ag) = 34.286 ppm = 0.0034286 percent] Parts per million to percent to ounces per ton Ounces per ton to percent to parts per million Ppm Percent Ounces per ton Ounces per ton Percent ' Ppm 0.01 0.00003 0.3 0.01 0.000001 0.0003 .02 .00007 .7 .02 .000002 .0005 .05 .00017 1.7 .05 .000005 .0015 .10 .00034 3.4 .10 .00001 .003 , .20 .00069 6.9 td .20 .00002 .006 oo to .30 .00103 10.3 .30 .00003 .009 .40 .00137 13.7 .40 .00004 .012 .50 .00171 17.1 .50 .00005 .015 .60 .00206 20.6 .60 .00006 .017 .70 .00240 24.0 .70 .00007- .020 .80 .00274 27.4 .80 .00008 .023 .90 .00309 30.9 .90 .00009 .026 1.0 .00343 34.3 1.0 .0001 .029 10.0 .03429 342.9 10.0 .001 .292 20.0 .06857 685.7 20.0 .002 .583 50.0 .17143 1,714.0 50.0 .0.05 1.458 100.0 -.34286 3,429.0 100.0 .01 2.917 500.0 1.71 17,143.0 500.0 .05 14.583 1,000.0 3.43 34,286.0 1,000.0 .10 29.167 10,000.0 34.29 342,857.0 10,000.0 1.00 291.667 Statistical Treatment of Data The manipulation and synthesis of the geochemical information and the interpretation of geochemical distribution patterns depend on statistical analyses of the data. These analyses define anomalous values which may be related to metallic mineral occurrences. Because of the large volume of data, most statistical manipulations were per formed on a computer using the RASS II and STATPAC-series programs. The primary tool used to determine threshold levels of anomalous values for each element is a histogram of frequency of occurrence versus analytical value (for example, see fig. B-7 ). Since geochemical distri butions commonly approximate a log-normal distribution/ a log trans formation was performed on all analytical values prior to plotting the histograms. The log transformation allows the portion of the histogram which is above the detection limit for each element to be treated as an approximation to a portion of a normal distribution curve. A complete set of histograms was produced for all stream-sediment samples and for all samples in each bedrock geochemical unit. Stream Sediments Because the stream-sediment samples are derived from different rock types and because of site variability and other factors, a single thres hold value was not used for some elements. Instead, two threshold levels were used: anomalous and distinctly anomalous. Anomalous values are those either in the upper five percent of the values reported or those with some what higher than normal geochemical abundance values following Levinson (1974) B-83 As single samples they may represent only variability due to sampling or analytical techniques. Anomalous values are considered significant only if they occur in clusters. Distinctly anomalous are those in the upper two percent of the values reported for the element and so far above the normal geochemical abundance values that they suggest mineral ization. The histograms were inspected for natural breaks (bimodal distributions) and for "tailing out" to the highest values and anomalous levels adjusted as necessary. This process was intended to avoid either 1) selecting the high end of a statistically normal population from essentially nonmineralized samples or 2) selecting too high a thres hold level from a heavily mineralized area. The anomalous levels used for stream-sediment samples are given in table B-4; figure B-7 shows the histograms used to select these levels for the elements of interest. The locations of anomalous stream-sediment TABLES B-4 AND B-5 AND FIGURE B-7 NEAR HERE samples are plotted and identified by sample number on plate 2., T.able B-5 contains the analytical data for the 331 stream-sediment site means which meet or exceed the threshold levels in one or more elements. Elements not shown in tables B-4 and B-5 were not included in the geochemical interpretation because they were either not pertinent to the economic potential of the area or because of the lack of values above the instrumental detection limits. Plots of all the analytical data for each individual element are available in Johnson (1978). B-84 -Table B-4. Anomalous levels for selected metals in stream sediments as used on plate 2 and figure B-7 Element Anomalous at: Distinctly anomalous at: (ppm) Ag 0.5 -N2 M2 As 200 N2 Be 1.5 Co 70 N2 Cr 300 1,000 Cu 150 200 Mo 7 20 Ni 150 N2 Pb 50 100 Sn 10 N2 Zn 200 300 AU1 0.05 N2 CU1 150 N2 Hg1' 0.25 N2 Pb1 30 70 Zn1 150 300 Analyses by atomic absorption, all others by semiquantitative spectrographic method. 2 No distinctly anomalous level selected for this element. B-85 « --, I J; Ag .75 Au 25 .5 .05 7 As Be 25 m 20 o .1 10" B 200 1000 B I 50 20 Jl Jl Co Cr 10- 10 20 100 100 1000 CONC. (PPM) Figure B-7. Histograms of the distribution of selected metals in stream- sediment samples. Analyses by semiquantitative spectrographic methods except as noted. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-4). Samples plotted as "B" were below the limit of detection. Analyses by atomic absorption. B-86 £3-1 25- 20 20- rT. Cu Cu; 101 10- 100 IOOO 160 IOOO 92*n .rJ 20- Hg1 m Mo O t- 10 -02 5 to- N Ni Sn .or 10- t s 100 a 10 K)O TOO CONC. (PPM) Figure B-7. Continued (two of three). B-87 so 30 20 Pb" Pb 10 10 10 100 B 6 100 -n SO rn o ft .8' 25 .4 Zn 20 Zn I 10 n n 100 IOOO 100 CONC. (PPM) Figure B-7. Continued (part three of three). B-88 T.ihle l>-5 . ~-f noroal on s i»nrl Distinctly anonalous r. t reejm- sr-d i men r rotloctert hy t h <» Geological Survey. S a IP p 1 P Loti t u ci e Longitude An (ppm) As ( npr-) AU (ppm) R (ppm ) Ba < ppm) Pe (pom) Bi (ppm) Ca (X) m 66AFQ? f> Sfi 57 Sni" 136 O'- 1 OW L L L 10 500 L L 5.00 so on ?/.M 1 ?ft 06 35W L I L 15 500 L L 7.00 66AFOM 58 ?9 1 ?M 135 51 ?OU L L L SO 500 L L 7.00 66AF067 58 43 f ) 7 1, 135 47 1 5W L L L 70 300 L L 3.00 66AF12K S8 57 1 1N 1 35 5? OOW L L L 70 700 1 L 2.00 A 66AFU 3 58 40 2RN 136 32 52W L L L ' 15 200 L L 70.00 66AF19X sa 51 1 1M 136 56 1 5W L I L 70 300 L L 3.00 4* 66AF199 58 51 ? on 136 56 20W L L L 70 700 L L 3.00 66AF201 58 51 57M 136 56 21W L L L 20 500 L L 3.00 66AF354 58 24 26N 136 23 52W L L L 30 100 L L 1.00 * 66AF402 58 53 09N 137 01 43W L L L 10 300 L L K50 66AF418 58 56 2 OH 135 39 42U L L L 15 500 L L 1.50 66AF419 58 57 46N 135 36 31W L ?0 L L 1.50 * L L 500 66AF420 58 57 32N 135 37 20W L L L ?0 300 L L 1,50 66AF421 58 56 ION 135 38 55W L L L 10 500 L L 1.50 * 66AF423 58 55 41N 135 40 54 W L L L 15 500 L L 1.00 W 66AF444 58 53 39N 136 38 51W L L L 20 300 L L 3.00 I 66CH010 53 35 07N 136 12 58W L L L 70 300 L L 3.00 ** >£> 66CH023 58 39 46N 136 17 40W L L L 15 30 L L 15.00 66CH024 58 39 57N 136 18 1 3W L L L 30 30 L L 20.00 M 66CH048 58 36 13N 136 22 03W L L L 15 200 L L 7.00 66CH105 53 46 53N 136 00 1 5W L L L 15 1 50 L L 10.00 66CH1 39 58 55 06N 135 42 34W L L L 10 700 L L 5.00 « 66CH169 58 52 57N 135 36 56W L L L ?0 700 L L 3.' 00 66CH170 58 52 35N 135 40 SOW L L L 15 500 L L 2.00 66CH173 5« 47 20N 135 45 16W L L L 50 300 L L 7.00 mi 66CH174 58 49 26N 135 45 05W L L L ?0 300 L L 7,00 66CH175 58 49 31N 135 44 47W L L L 10 300 L L 7.00 ^ 66CM176 58 51 Q3N 135 44 06W L L L 20 500 L L 7.00 66CH177 58 50 31N 135 50 2PW L L L 30 300 L L 7.00 66CH193 58 56 34M 135 55 44W L L L 10 500 L L 5.00 ^ 66CH??9 58 48 59M 136 10 33W L L '. L 50 200 L L 5,00 66CH230 53 49 SON 136 11 39W L L 50 200 L L 5.00 66CH231 58 49 01fl 136 1 3 34U L L L 50 100 L L 3.00 ^ 66CH233 58 50 DON 136 14 05W L L L 50 200 L L 7.00 66CH235 53 49 3 ON 136 15 ?8W L L L 30 1 50 L L 7.00 66CII236 51 53 14N 136 09 55W L L L 300 L L 1.50 66CH237 53 53 ?7n 1 36 10 25W L L 10 700 L L 1.50 Table U-5.--Anoroalous and distinctly anomalous stream-sediment samples collected by the Geological Survey.-continued Sampl e C d (ppro) Co (ppm) C r (ppm > Cu (ppm) Fe (%) La (ppm) Mg (X) Mn (ppm) Mo (ppm) Nb (ppm) 66AF029 L 7 20 1 5 3.00 L 1.50 700 20 L 66AF032 L 15 20 20 3.00 ?0 1.50 1000 20 L 66AF061 L 30 100 150 10.00 20 3.00 1500 20 L 66Af 067 L 30 150 150 10.00 20 3.00 1000 L L 66AF128 L 30 70 100 7.00 20 1.50 700 L L 66AF U3 L 30 70 50 5.00 L 7.00 1000 20 L 66AF19J? L 50 150 150 15.00 L 5.00 1500 L L 66AF109 L 30 100 1 50 10.00 L 3.00 1500 L L 66AF201 L 20 50 100 5.00 20 1.50 1500 L 66AF354 L L 10 20 20 2.00 L 0.70 700 L L 66AF402 L 30 70 100 3.00 L 1 .00 700 15 L L 30 5000 70 3.00 20 1.50 700 L L 66AF419 L 30 70 70 3.00 50 1 .00 700 L L 66AF420 L 30 150 70 5.00 30 1,50 700 L L 66AF421 L 20 500 50 3.00 L 2.00 700 L L to 66AF423 i L 30 1000 70 5.00 20 1 .50 700 L L 66AF4'./, L 50 50 150 5.00 L 5.00 1500 L 66CHP10 L L 20 30 150 5.00 20 1 .50 1500 L L 66CH023 L 10 L 10 3.00 L 7.00 700 L L 66CH024 L 15 30 20 3.00 20 10.00 700 L L 66CHO/.8 L 50 30 150 15.00 L 3.00 2000 L L 66CH105 L 50 300 50 7.00 ?0 2.00 1500 L L 66CH1 39 L 30 700 70 5.00 20 3.00 1500 L L 66CH1S1 L 3T 70 100 7.00 50 2.00 1500 L L 6ACH1 A8 L 15 70 70 3.00 20 2.00 1 500 L L 66CII169 L 50 1000 150 7.01 L 5.00 1500 L 66 CM 70 L L 15 20 0 100 5.00 50 1 .50 1000 20 L 66CH173 L 50 150 50 7.00 20 2.00 1000 20 66CH174 L L 30 70 50 5.00 70 2.00 1000 20 L 66CH1 7S L 15 30 30 3.00 ?0 1 .50 1 500 20 L 6 66CH236 L 5 L 20 0.50 700 20 L 66CII237 L 5 L 5.00 20 0.70 1000 20 L Table 9- 5.--Anoma lou s and distinctly anomalous stream-sediment samples collected by the Geological Survey.-corit i nued Sa mple Ni (ppm) Pb (pom) Sb (ppm) Sc 66AF029 10 L L 10 L 300 0.300 100 L 15 66AF032 1 S L L 15 L 500 0.500 100 L 15 66AF061 30 30 L 20 L 300 0.300 200 L 20 66AF067 70 ?0 L 20 L 200 0.700 200 L 20 66AF123 70 50 L 15 L 300 0.500 150 L 15 10 ' 66AFU3 30 L 1 5 L 700 0. 300 100 L 15 66AF198 70 15 L 30 L 300 0.700 300 L 30 66AF199 70 20 L 30 L 300 0.700 300 L 30 66AF201 30 10 L 20 20 300 0.700 200 L 20 66AF354 L L L 1 5 L 100 0.200 100 L 20 66AF402 30 10 L 1 5 L 200 0.200 100 L 15 66AF413 70 15 L 15 L 300 0.300 100 L 20 6AAF419 30 30 L 1 5 L 200 0.300 100 L 30 66AF420 50 30 L 15 L 300 0.200 150 L 30 66AF421 70 20 L 1 5 L 300 0.200 100 L 15 66AF4?3 70 15 L 20 L 300 0.200 100 L 20 66 A F 4'.4 SO L L 1 5 L 300 0.300 150 L 15 66CH010 20 10 L 1 5 L 300 0.500 200 L 20 66CH023 15 30 L 5 I. 100 0. 150 70 L 10 66CH024 15 70 L 7 L 200 0.300 100 L 15 66CH04R 15 L L 30 L 200 0.700 300 L 50 66CH105 70 L L 30 I. 300 0.700 200 L 30 66CH139 70 10 L 1 5 L 500 0.500 200 L 20 66CH151 30 100 L 30 L 500 0.700 150 L 15 66CH168 20 150 L 10 L 300 0.300 100 L 20 66CH1A9 150 30 L 30 L 300 0.700 300 L 15 66CH170 30 L L 10 I. 300 0.500 150 L 70 66CH173 50 10 L 1 5 L 300 0.500 200 L 30 66CII174 50 10 L 1 5 L 500 0.500 200 L 20 66CH175 ?0 L L 10 L 500 0.300 150 L 15 66CH176 L L 1 5 L 500 0.700 300 L 20 66CH177 50 L L 20 L 50Q 0.700 200 L 20 66CH193 20 L L 1 5 L 500 0.700 300 L 30 66CH226 70 10 L 1 5 I. 500 0.700 200 L 20 66CH22E 70 10 L 1 5 I. 500 0.700 200 L 20 66CH229 50 10 L 1 5 L 300 0.500 200 L 15 66CH230 30 10 L 1 5 L 500 0. 300 150 L 15 66CH231 50 L L 15 L 300 0.700 200 L 15 66CH233 50 10 L 1 5 L 500 0.500 200 L 20 66CH?3 C> on 10 L 20 I. 500 0.700 200 L 15 66CH236 L L 7 3 00 0.300 70 L 15 66CH237 L L 7 300 0. 300 100 L 15 Table D-5.--AnomaIous and distinctly anomalous stream-sediment samples collected by the Geoloqical Survey.-coritinued .1 Sample 7n (ppm) Ir (pom ) Au (ppm) Cu (ppm) Hf] (ppm) Ph (ppm) Zn (ppm) 66AF029 L 70 L 20 10 35 66AF032 L 1 SO L 25 10 40 66AF061 L 1SO L PO 10 30 66AF067 L 150 L 50 20 R5 66AF12t L 1 50 L 60 30 110 66AF143 L 30 L 30 20 30 * 66AF19R L 150 B 1 40 15 65 L 150 L 95 15 60 66AF201 L ?00 L 70 15 50 66AF35/, A L 300 D .?, 5 30 80 66AF402 L 100 0. 10 /, 0 5 15 66AF41P L 100 L 100 25 110 66AF419 L mo B 75 30 130 66AF420 L 100 L 90 35 140 66AF421 L 100 L 90 20 100 to 66AF423 L 100 L 85 15 85 66AF444 L 100 L 100 15 70 to 66CH010 L 150 L 00 10 55 66CH023 L 15 L 5 20 150 66CH024 L 30 B B B B 66CHP4? L 300 L 40 10 45 66CM105 L 150 L 40 20 70 66CH139 L 150 L 90 20 90 66CH151 L 150 L 45 10 35 66CH16K L 100 L 30 20 1 30 66CH169 L 70 L 130 30 120 66CH170 L 150 L 60 15 75 66CH173 L 150 L 60 20 85 66CH174 L 200 L 50 15 85 66fH175 L 150 L 30 10 45 66CH176 L 300 L ?5 10 40 66CH177 L 150 L 45 15 70 66CH193 L 200 L ?5 10 40 L 150 L 70 20 95 66CH22P L 150 L 60 20 75 66CH22'/ L 100 L 55 20 75 L 1 50 L 60 25 85 66CH231 L 100 L 55 15 40 66CH2 7,3 L 100 L 55 15 65 66CH23S L 150 B 50 15 50 L 200 L 5 5 15 66CH?37 L 300 L 5 5 20 latle b- 5. --Anoma I ous and distinctly anomalous s t r e air -sed i men t samples collected by the Geological Survey.-c ont i nued Sample latitude Lonqitude Aq (ppm) As (ppr) A u (n p m ) n (or>m) Ra (ppm) Re (pom) Ri Ca (X) r P 66CH? 7;*- 54 Of N 136 1(i f, 1 W I. 1 L m 500 L L 3.00 66O<2:'V Sp 54 (|0(" 136 10 ?nw L 1 L L 500 L L 2.00 A 'j1 66CM2M 1 SR 1 ^M 136 1 1 53W L L L 20 300 L L 7.00 66CH241 SI 51 0°N 136 11 4 5W L L L 20 500 L L 5.00 * 66f I'?/. 3 SR 47 33N 136 1 3 P4W L L L 70 300 L L 2.00 r.H 66CH? r fr 46 2SN 136 17 01W I L L 50 300 L L 7.00 66CII257 58 46 39M 136 1* 06W L L L 50 300 L L 10.00 m 17K' 66CH270 58 48 136 22 1 3W L L L 15 300 1 L 7.00 66CH?79 5°. 49 47M 136 17 52W L 300 L 70 1 50 1 L 7.00 * 66CH302 58 57 01 U 135 52 1 1W L L L 70 700 1 L 3.00 66CH304 58 57 04N 135 56 1 5W L L L 10 500 1 L 5.00 m 66CH305 58 59 26N 135 55 26W L L L 10 300 L L 7,00 66CH479 58 20 45n 136 09 23W L L L 20 200 1 L 2.00 66CH490 53 23 09N 136 34 40W L L L 50 50 L L 5.00 m 66CH503 58 25 53N 1 36 1 2 18W 0.7 L L 50 500 L L 1.50 ro 66CH636 58 57 47N 135 36 22W L L L 15 300 L L 1.50 m, 66FM001 5,} 35 ?/,N 136 08 25W L 100 300 L 5.00 66EM003 58 35 M n 1 36 0? 1 3W L 70 500 1 3.00 * ** »»» O O {> O O O> O> O* {> O> O- O> o- {> ^ {> O- {>{>{> O> O- {> {> O> O> O> O> O {> O> O> o O- t> O> £ O O O O > O"O> O" O» O O- O" C^^^O-O" CT> O1 O1 &> O» O-O>^^^ O ^ ^ ^ ^ O> O» O- ^ ^ c>O»^O-O- CT> &> O- O- O t/> mm o C5 <^ c? ^ ooooo ooooo ooooo o o o o n nnnnn < *» o o o /^ o <"*» o r*> <~» s; 3-2 33 1 3 -3 OJ :D 3 "3 S3 T3 a3CT)CD3 ODCDTICDOD CDTIZII IZ2ZX XrTXTI ZXXXX 3 "DO o^vno^v/i vji'jJ'/J^JjJ fviiL> OOOOO OUOOO >^>^OOO OcnOOO OO^OO OO^OO OOOoi-vl 3 r-o ooor-o r-oooo ooooo ooooo ooooo r-oooo DOOOO ooot-r- 3 oo rsbor-o oocioo ooooo ooooo ooooo oooob ooooo ooo-s 1- 3 O O O OO OOO-nO OOOOO OOOOO OOOOO .OOOOO OOOOO OOOOO OOOO-3 OO OOOOJ OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO o oo ooooo o r- r- r- r- r-oooo ooooo OOOP-O or-ooo ooooo r-oop-o 3 OO O O O s/> O OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO -^ O 3 i-o ^i-"jO"W"W ^/»OO*/»O ^/»O>j-w>J O k/i iji O i-" -NJ \ji Ji O >y» O'J'O'ON O 00 OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO O OO OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO OOOOO 3 o O I OOOr-p- fp-r-r-r- p-p-p-r-r- f r- r- o f OOO.OO 3 O 3 z C» cr j. Table 9-5.--Anomatous and distinctly anomalous stream-sediment samples collected by the Geological Survey.-contfnu«d Sample N i (rpm) Pb (ppm) Sb (ppm) S C ( P R 0) ) Sn (ppm) Sr (ppm) T i (X) V (pom) W (opm) Y (ppm) 66CHP3R 7 L L 10 L 500 0.300 100 L 15 66CHP39 5 L L 7 L 300 0.300 70 L 10 66CH24P 50 L L ?0 L 300 0.700 200 L 20 66CHP41 ?0 L L 15 L 500 0.500 200 L 15 66CH243 70 10 L L 200 0.700 200 L 20 66CHP56 50 ?0 L L 300 0.700 200 L 30 m 66CH25? 50 15 L ?0 L 10PO 0.500 200 L 20 66CH?70 20 10 L 1 5 L 700 0. 500 150 L 20 66CH279 30 10 L 15 L 300 0.500 150 L 20 * 66CH302 100 70 L 1 5 L POO 0.500 150 L 70 66CH3CK 30 - 70 L 10 L 500 0.700 ?00 L 20 66CH305 70 20 L ?0 L 300 0.500 ?00 L 20 66CH479 20 10 L 1 5 L 1 50 0.500 200 L 30 66CHA90 70 L L 50 L 300 0.700 500 L 15 66CH503 30 20 L 15 L POO O.?00 100 L 15 66CH636 30 50 L 1 5 L 300 0.300 100 L 30 At vo 66CH637 150 15 L ?0 L 500 0.300 150 L 15 ^ en 66CH63& 70 10 L 1 5 L 3CO O.?00 100 L 20 66DB011 20 15 L 1 5 L 300 0.500 150 L 20 * 6600135 150 10 L 30 L 500 0.700 300 L 30 66DBU? 70 30 L 1 5 L 300 0.500 150 L 20 66DBU3 30 L L 15 L 700 0.700 POO L 30 « 66DH161 15 L L 7 L 700 0.300 150 L 15 66DB1A2 10 L L 7 L 500 0.500 150 L 20 66DP165 1 5 L L 15 L 500 0. 300 150 L 20 66DB315 70 70 L 15 L 100 0.500 200 L 20 66DP31F 70 30 L 1 5 L P.OG 0.500 200 L 20 66DB319 5U 30 L 1 5 L L 0.300 200 L 20 66Dfl3?8 70 70 L 1 5 L POO 0. 300 150 L 15 66Df 349 70 10 L 30 L 300 0.700 300 L 30 66DB39? 70 20 L L 300 0.500 300 L 20 66DH393 100 10 L 30 L 300 0.500 POO L 15 66DP395 70 10 L 50 L 300 0.500 300 L 20 70 10 L 30 L 300 0.500 300 L 20 66DP5A2 7 30 L 10 L 200 0. 300 100 L 70 66Dl>563 7 30 L 10 L 1 50 O.POO 100 L 50 66DOS48 L 30 L 5 L L 0.070 10 L 50 660R569 5 10 L 30 L ^00 0.500 300 L 20 66DPMO 10 500 L 1 5 700 100 0. 200 150 L 20 66DU646 ?0 15 L * 1 5 30 300 0.200 150 70 20 66EH001 1 5 30 L 10 L 200 0.300 150 L 15 66EMP03 10 30 L 10 L 100 0. 300 150 L 15 Table 3-5.--AnoroaIous and distinctly anomalous stream-sediment samples collected by the Geological Survey.-continued Samole Z n (pom) I r (com ) Au (ppm) Cu (opn>) Hq 1 (opm) Pb (pom) In (pom) 66CH238 L 200 L 10 5 15 66CH239 I 150 L 10 5 10 66CH240 L 150 L 35 10 30 66CH241 L 1 50 L 25 10 35 66CH243 L 150 L 75 25 100 66CH256 L 150 L 35 20 55 66CH257 L 150 L 35 20 45 66CH270 L 150 0. 10 35 5 35 66CH279 L 100 L 40 15 40 66CHID2 L 150 L 70 40 120 66CH304 L 150 L ?5 15 35 66CH305 L 150 L ?5 10 25 66CH479 L 150 L 50 20 160 66CH49Q L ?0 L 100 5 55 66CH503 L 150 L 160 10 35 66CH636 L 150 0.20 75 25 90 66CH637 L 30 L 160 35 fiO 66CH678 L 150 fl 0 B 0 66DB011 L 150 O.C5 30 15 50 66DP.H5 L 150 0.30 ?0 90 66DBU2 L 150 L 55 30 1 10 66DP143 L 150 0. 15 30 10 65 66D6161 L ?00 L 40 5 25 66DP162 L ?00 L 15 5 20 660P165 L 200 L ?5 10 50 660P?1 5 L 1 50 L 80 35 130 66DP318 L 150 L 75 40 1.30 66DP319 L mo L 120 50 150 66DP328 L 100 0 1 30 65 140 66DP349 L 200 L 55 5 40 L 150 L T 0 20 70 66DP? 66DG563 L 300 L 1 5 20 65 66DP568 L 1 50 L L 10 25 66DP569 L 50 L 1 40 10 35 66DP610 L 150 8 1/.0 ?5 1 20 6600646 L 150 L 45 10 35 66EM001 L 150 L 65 40 120 66FM003 L 1 50 R 35 50 85 Table B-5. Anomalous and distinctly anomalous stream-sediment samples collected by the Geological Survey.-continu«d Samp Ie La t i t ude Longitude Aq (ppm) As (pom) Au (com) 8 (pom) Ba (opm) Be (pom) fli (oom) Ca (X) 66EP008 5R 35 03fJ 136 07 49W L L L 15 300 L L 10.00 ^ 66EK011 53 37 34N 136 10 45W 5.0 L L 70 50 L 15 7.00 66EftP1g 58 37 51 N 136 10 53W L L L 50 300 L L 5.00 66EPP22 53 35 1 ON 136 05 43W L L L 1 00 200 1 L 5.00 m 66EN274 5? 50 19N 135 40 29W ' L L L 70 700 L L 0.15 66EM275 58 50 16N 135 40 53W L L L 15 500 1 L 5.00 -I 66EM2P-3 58 35 41 N 136 07 49W L L L 15 300 L L 10.00 66EP?P', 58 35 14N 136 07 17W L L L 30 300 L L 10.00 66FM436 53 23 3 ON 136 2P 06U L L L 20 500 L L 3.00 g| 66ET45C 58 22 53N 136 36 45W L L L 50 200 L L 5.00 . 66EM458 58 22 38N 136 36 SOW L L L 50 1 50 L L 5,00 m 66EM50P 58 33 3 «M 136 25 36W L L L 30 500 L L 1.50 m 66LH128 58 52 53N 135 36 48W L L L 15 300 L L 10.00 66LH129 58 52 5PN 135 37 25W L L L 20 500 2 L 0.50 66LH133 58 52 23N 135 40 5PW L L L 15 1000 L L 7.00 66LH1 39 58 54 2PM 136 0? 58W L L L 20 300 L L 3.00 td 66LH140 58 55 31N 136 0? 51W L L L 20 300 L L 3.00 66LH241 58 53 17N 136 56 1 1W L L 10 1 50 L L 7.00 66LIIP4? 58 53 09N 136 56 Ofiw L L 20 700 L L 5.00 <» 66LM244 58 52 33K 137 02 1 2W L L 10 300 2 L 1.50 66LHP45 58 51 19f.' 137 04 21W L L 15 300 2 L 0.70 66LH?04 58 27 02N 136 05 10W L L 300 L L 5.00 « 66LH321 58 22 44f. 136 17 28U L L 70 300 1 L 1.50 66LH3?2 5* 2? 3?N 136 17 1 7W L L 70 300 L L 1.50 & 66LH325 58 22 14N 136 17 01W L L 70 200 L L 1.50 66LH327 58 21 37N 136 16 2«W L L ?0 300 L L 2.00 66LH349 58 39 26N 135 56 1 8U L L 20 300 L L 1.00 * 66LH351 5° 43 26f! 135 58 35W L L 15 3000 2 10 1.50 66LH35? 58 43 1 9N 135 5f> 27W L L 20 700 1 L 1.50 <^ 66LH3M 59 02 47N 1 37 04 19W L L 15 300 1 L 1.50 66LH364 S9 03 45N 1 37 04 42W L L 10 300 1 L 1.50 66LH?/>7 5Q 03 20r 137 01 17W L L 50 300 L L 3^00 + 66LH368 59 02 36N 137 00 16W L L 15 300 L L 7.00 66LH77? M 5? 15N 136 48 OOW L L 20 100 L L 5.00 & 66TOOD1 5R 52 56H 135 49 02W L L 3f> 300 L L 7.00 66TOPD3 58 53 34M 135 46 34W L L 20 700 L L 5.00 66TOP05 5* 54 3 P t! 135 50 44W L L 15 500 1 L 5.00 66TOf>1 1 52 451^' 155 50 53W L 15 500 L L 7.00 66TOP1? 5 ? 5 5 N 175 50 ?5W L 15 300 L L 7.00 U-5.--Anoro.iloiJS and distinctly anomalous s t roan-s*ri i men t samples collectel by the Geological Survey.- c ont i S a m p ( P (un Co (pom) C r ( o p PI > C u (oor) La (oom) * o (% > Mn (pom) Mo rib (pom) 66FMODP *0 ?0 7P 5.00 L 3.00 1000 L L 66fMO 11 30 20 70P 3. OP 20 5.00 3000 L L 66EM01}1. 7-0 50 Ml s.oo 20 2.00 1500 L L 66EMfi?? 15 20 300 5.00 30 1 .00 700 L L 66FM27A 15 70 100 7.00 ^0 0.50 700 70 L 66EM27S 30 L 150 15.00 50 1 .50 3000 L L 66FN283 15 SO 3D 3.00 20 7.00 1500 L L (9» 66EM28A ?0 70 3D 7.00 20 3.00 1500 L L 66EVA36 ?0 30 30 7.00 20 2.00 1500 L L 66FHAS6 50 150 200 10.00 L 2.00 1500 L L 66EMA58 50 200 150 15.00 L 3.00 1500 L L 66EM508 30 50 30 7.00 20 1 .50 1000 ?0 L 66LH12R 30 700 100 5.00 L 10.00 1500 L L 66LH129 20 300 70 5.00 20 1 .50 2000 L L 66LH133 15 150 150 5.00 30 1.50 1500 L L 66LH139 ?0 100 00 50 15.00 50 1 .50 1500 20 L 66LH1AO 15 30 30 5.00 20 1 .50 1500 20 L 66LHU1 10 00 20 20 3.00 ?0 1 .50 1000 20 L 66LHU3 10 30 20 5.00 20 1 .50 1500 L L 66LH2U 15 70 30 3.00 30 1 .50 1000 L L 66LH2A1 30 100 150 7.00 L 2.00 1500 L L 66LH2A2 70 200 200 10.00 L 3.00 1500 L L 66LH2AA 15 30 30 3.00 20 1 .00 1000 L L 66LH2A5 7 L 10 1 .50 50 0.30 700 L L 66LH304 20 50 30 5.00 20 1 .50 1500 L L 66LH321 30 50 150 3.00 L 1 .00 1500 L L 66LH322 30 70 ISO 7.00 L 1.50 1000 L L 66LH325 30 70 300 10.00 L 1 .50 1 500 10 L 66LH327 20 70 100 10.00 30 1 .50 1500 L L 66LH3/.9 20 70 SO 2.00 20 1.00 1000 L L 66LH7S1 30 50 150 3.00 1 50 0.70 1500 30 L 66LH352 20 50 50 3.00 70 1.00 1000 20 L 66LH361 15 30 20 3.00 20 0.70 700 L L 66LH36A 15 20 150 3.00 20 1 .00 1000 L L 66LH367 20 50 30 7.00 70 1 .50 1000 10 L 66LH368 30 150 70 10.00 50 3.00 1500 200 L 66LH372 53 300 ?90 7.00 L 3.00 1000 L L 66T0001 30 300 50 10. 0^ L 2.00 1500 L L 66TOf'03 30 50 7.00 20 2.00 1500 L L 66T0005 10 30 200 3.00 20 1 .50 1500 L L 66TOP11 ?0 70 20 5. OH 20 2.00 1500 20 L 66T0012 20 50 50 3.00 70 2.00 1000 20 L B- £ -- Anoma I ous and distinctly anomnlous s t re am -seel i men t samples collected by the Geological Survey. - coht i nued Sairp I e t H ( p p "> Pb (npm) Sh (ppm) Sc ( com) >n* (ppm) Sr (opm) T i (X) V (ppm) W (poni) Y (ppm) 66fMPOF 50 L 1 5 L 300 0.500 66-EM01 1 10 500 200 L 20 L 7 L 100 0. 150 70 66EWP1F .30 10 L 1 5 L 10 L 300 0.500 150 L 6 Sample Zn (ppm) Ir ( ppm) (ppm) Cu (opm) Hq ( pp m) Ph (ppm) Zn (ppm) 66EN008 L 70 L 40 ?0 70 *» 66EM01 1 500'1 20 L 6?0 66FM018 L 6500 L 70 20 ?30 66EPC22 L L 450 40 66EH274 500 7 r> 120 * 150 L 60 SOO 6 6 £ f ? ^ 5 L 150 L 65 25 170 O O E r c 3 L 150 4* L ?0 20 65 66EP2P4 L 100 L 30 20 60 66EK4 :«l6 L 300 1 .00 25 15 45 66EM456 L * 100 L 180 15 70 66EH458 L 100 L 120 15 66EH508 55 * L 300 B 10 5 66LH128 20 L 50 L S5 20 110 66LH129 L 150 L 70 20 66LH133 100 * L 300 L 45 20 120 W 66LH139 L 300 0 45 1 L 10 50 66LH140 300 L 35 10 o 66LH141 50 L 1 50 L 25 10 o 66LH143 L 30 150 L 15 5 25 66LH214 L * POO 0 .05 ?0 10 50 66LH241 L 100 L ?10 10 66UI242 45 L 70 L 200 15 90 w 66LH244 L 150 L 55 10 50 66LH245 L 150 L 1 5 5 20 66LH304 L ',5 * 150 0 .10 15 65 66LH3?1 200 1 50 fl 150 60 2PO 66LH322 L w£i 100 L 14C 30 160 66LH3P5 L 200 fl 290 35 66LH327 90 L 700 P 30 35 90 66LH349 L ^ 100 L 65 35 120 66LH351 L L 110 35 75 tfk 66LH752 L 150 0 . 10 65 w 66LH361 25 65 L 200 0 .05 25 5 35 66LH364 L 150 L 35 5 40 66LH367 L ^ 200 fl B B 66LH368 L ?00 L 35 10 66LH?72 ?0 L 100 L 2?0 10 w 66T0001 L 55 1 50 L 40 10 50 66TOC03 L 150 L 55 15 70 66T0005 L ^ 150 L 30 10 45 66TOM 1 L T 0 150 L 10 40 o!. 66TOP1? L 100 L 40 15 50 00*02 058 U02 1 M£0 92 5£l MV I SZ 85 z s i H a s z GO'S I OS8 521 1 M2S 52 Sil M«0 si 85 ssiaasz -\ U05 U51 f1V I Sil u OS'21 T 002 J52 1 MIS 20 9il NZO ZV 85 990T8SZ OS'Zl T 058 002 1 M81 65 Sil M65 i V 85 i9jresz 1 1 N?2 00'2 005 U2 -\ M90 8V 9i i 05 85 16J0199 OS'l 1 OOS OZ M£2 VI 9£l us 5 12 8 5 6V00199 O0'£ 1 OOS 51 1 M20 6V 9il tJZO 15 85 I V00199 O0'£ 1 OOS UZ 1 M6 V UV Sii N5 I It 85 l£,)0199 M&i OS'l 1 00£ OZ -\1 ZV Sil .i (X) (UlOU) (mad) ( (tuaci) b\/ opnjibuo-j a 1 psnu i JUOD- 'AaA jn$ ie3ibo]Od'j Xq p«MD«M]OD s sno]eiuoue put s no ) PUJOU v-- 'g - Table 0- '5. --AnomaIous and distinctly anomalous stream-seriiment samples collected by the Geoloqical Survey.-continued Sample (ppm) C o (pom ) C r (opm) C u ( n p ir.) Fe La (oom) 1 q ( X ) (com) MO (ppm) Nb (ppm) 66T0013 L 20 50 3d 5.00 30 1.50 1500 L 66T0014 L ?n 50 *n 5.00 L 2.00 1500 20 L 66T0023 L 30 70 70 10.00 ?0 2.00 1000 L L 66TO(V4 L 30 50 150 10.00 20 1.50 700 L L 66T0031 L 1 5 70 50 5.00 20 1.50 700 L L 66T0041 L 30 70 30 5.00 1.50 1500 L L 66T0049 L 15 20 30 3.00 20 1 .50 1000 L 66TOP91 L L 20 70 ?0 20 0.70 700 L L 75BJ061 L 50 100 250 fl5 3.00 ?000 L L 75CJ066 L 60 125 150 15.00 60 5.00 1500 L L 75PJP67 L 50 100 175 io.no 70 5.00 1500 L L 759J081 L 10 18 25 4.00 125 1.50 1750 L L 75BJ084 L 25 65 *5 5.00 P5 2.50 1750 L L 75CC065 L 40 50 70 7.00 50 1.75 1750 L L 75CC068 L 40 60 50 7.00 60 1.50 >5000 L L 75CC085 L 13 60 185 7.00 50 2.50 1750 L L 75CC089 L 40 125 50 11 .00 35 2.50 2000 L O 75CC111 L to L 30 33 40 4 .00 23 1.75 1250 L L 75CC114 L 25 25 25 3.00 25 1 .50 1500 L 75CC116 L L 20 1 5 50 6.00 20 1.50 1250 L L 75CC118 L 30 25 50 5.00 ?5 1 .75 1500 L L 75CC122 L 25 40 40 4.00 L 2.50 1250 L L 75CC124 L 25 13 40 3.50 20 1.25 1750 L L 75DD129 L 60 100 175 7.00 50 3.00 1500 L L 75DB131 L 25 60 70 7.00 70 3.00 1500 L L 750B134 L 50 70 1000 10.00 70 3.00 2000 60 L 75DB138 L 50 100 2^0 * 10.00 85 4.00 2000 L L 75DH140 L 30 85 400 8.50 85 6.00 1750 L 75PB141 L L 40 225 300 1 2.50 1 10 6.00 1500 L L 7 5 0 P 1 4 2 L 60 70 2?5 1 5.00 60 6.00 3000 L L 75 Din 43 L 35 125 ?00 1 ?.50 50 6.00 1500 L 7 5 0 P 1 4 5 L L 40 110 1?5 11 .00 70 6.00 1?50 L L 75DBU7 L 30 125 70 7.00 1 25 3.00 1500 L L 7 5 D B1 4 8 L 3D 150 1 10 K.50 100 3.00 1500 L L 75I)B14'> L 70 225 ?5D >?0.00 75 6.00 ?000 L L 7 5 D B 1 5 0 L 25 150 125 ».50 70 6.00 2000 L 75DH151 L L ?3 1 10 *5 R.50 70 .00 1500 L 750B152 L L 25 100 1 10 H.50 60 .00 1500 L L 75DH153 L 70 8S 300 20.00 60 .00 5000 L L 7 5 D in 5 4 L 40 150 125 °, .50 85 .00 3000 L L 7 5 n B 1 5 5 L 30 75 100 7.00 70 7.00 1 500 L 75PR157 L L 7C 100 ISO 10. 0" 70 7.00 2000 L L C O «« «Ti O iri O »A tri O O O O O«« «^» OOOOO OOingOOO O O O O >A O O O O O O O O O O OO Q «j »- »- «\» ^- KI - ^- «<"» » w> «r» »A «\» «\» KI trt AJ C *+ O 6 u Q i a o 6 OOOCO OOOOO OOOOO OOO«n»n OO«nO«n OOOOO OOOOO OCOOO OO u Q tnintnOO COCOO o O «"> «n o O O O r>- r>- o »n ^ O r>- O O c C C OCOOO m »n G O O CC O * > O fc o c £ M >«" > cOOOOC e o o o oooooOOOOO OCOOCocomo oocooOOOOC cOOOCO w o o c cooooOCOOO cooooOOOCO cooccOCOOO OCcc «- in 1/1 K> »n re in (M (\j O O OOCecO O O * 6 OOOOO OOOOO OOOJ«^ OOOOO OOOOO OOOOO OOOOJ OOOCiA OC C CCOC'tr CCO*AkT CCO ^ OCOOf- CC»^C.«/^ OC»T>(/iW~. Cu-O"^ CC^CfC E _l -1 -) _) _l _l _) _l _1 _J _l _l _i _l _l _) _J _J _1 _l _!_)_!_)_) _l _) _l _) _1 _)_!_(_)_) _!_!_)_)_' _l_l a Q S mmir. vni/\ ir> OCCO Cmvnir. to CCoC'&.oo Cjo^OCO OOOOC t/~. O C O O Otnw. oir CC CL ^ ^~ ^ ** *^ ^~ ^* ^vj f"- **j v^ ^" f\* fv» < fo (w^ ^» i»» ^ f\» ^ rvj ^% *>'^ ^". ^o sj i»o "*j fv fo K" r* ^O i"*t ^v fv.' f > "" ^ i^* Q "O e I IOOO OOCOO OK>J/>OCO K> _J iri f^. O ir>-JOCtri OOOOOO OOOCO OOt^CO c£ »-»-r-»-^ ^>, ^^ VI 3 J2 o c. t E c ^ 6 CC'OCO Oi/^CiAO iAi/^vn»/>O OOO^OOO O l/^ l/^CO OOOiAO ir>iAi/%o"> mi^i/>Oi/^ Q CCCCC- COOC-C OOOCC O C. -«- - ^ T- r~ r- r- ^ *.,-*.,. ^.^-^^^. ^.^.^^.^ ^^. to K* H* H* H* H* H" ^~- ^** c^ cc GJ cr co *^ *^ *^ B-103 f e * 0 * 9 9 * t t i ^ 3 Table B- 5. --Anomalous and distinctly anomalous stream-sediment samples collected by the Geological Survey.-continued Sample Zn (ppm) Z r (pom) Au (opm) Cu' (0pm) Hq (ppm) Pb (ppm) Zn 1 (ppm) 66TOC13 L 200 L 75 8 10 50 <* 66T0014 L 150 L 30 B 15 55 66T0023 L 50 B 50 B 20 100 6610024 L 150 L 80 B 25 85 m 66TOP31 L 100 L 45 n 20 100 66TOP41 L 500 0. 10 10 B 5 25 * 66TOP49 L 150 B B B B B 66TOP91 L 150 0. 10 30 B 15 40 75BJC61 L 250 L 120 0.15 20 115 m 75BJ066 L 200 L S3 0.07 15 68 75BJ067 L 200 L 63 0.15 38 1 35 75BJ081 L 500 L 25 0.04 5 25 m 758J084 L 600 0. 11 ?3 0.02 8 30 75CC065 L 175 L 48 0.15 25 150 m 75CC068 L 325 L 30 0.27 15 93 w 75CC085 L 650 L 1 5 0.04 10 20 H 75CC089 L 500 L 18 0.09 8 20 0 its. 75CC111 L 150 L 25 0.30 13 63 75CC114 L 150 L 1 8 0.27 15 53 75CC116 L 175 L 28 0.33 8 50 75CC11P L 100 L ?8 0.25 10 53 75CC122 L 25 L 38 0.27 13 53 + 75CC124 L 18 0. 27 30 0.37 58 88 75DR129 200 200 L 108 0.03 35 165 750B131 L 200 L 53 0.03 78 * 23 75DB134 200 200 L 320 0.05 15 165 * 75DP138 L 400 L 63 0.03 25 95 750P140 500 400 0. 17 75 L 40 200 75DB141 L 300 0. 19 43 n.os 23 70 750B142 400 300 L 75 0.04 20 103 * 75DBU3 L 250 0. 06 45 0.02 20 78 75DB145 L 300 L 58 0.10 28 00 * 75DB147 L 300 L 30 0.12 ?0 75 750B148 L 300 L 53 0.05 18 58 75DB149 300 300 L 73 0.05 35 1 70 + 75DP150 L 225 L 40 0.04 30 68 75DP151 L 225 L 40 0.06 33 68 * 75DB152 L 250 L 50 0.04 38 73 750B153 1 500 200 0. 06 80 0.05 90 475 75DP154 L 250 L 50 0.08 25 88 ^ 75DH155 L- 500 L 48 o.ns ?5 78 75DIM 57 L 400 L 43 0.04 15 53 Table 9-5\. --Anoma t ous and distinctly anomalous stream-sediment samples collected by the Geological Survey ,-contt nued Samnle Latitude Longitude Aq (ppm) As (oom) Au ' (oom) B (oom) Ra (pom) Be (pp«) Ri (ppm) Ca (X) 750B158 58 34 57N 135 27 18W L L L 1 SO 1000 1 L 6.00 750B159 58 34 56N 135 27 06W L L L 150 1250 1 L 15.00 7508160 58 35 01N 135 28 14U L L L 150 850 1 L 12.50 750B161 5 8 34 55N 135 29 32W L L L 200 850 1 L 12.50 A 7508162 58 33 49N 135 31 32W L L L ?nn 1250 1 L 12.50 750B163 58 35 49N 135 32 34W L L L 300 1000 2 L >20.00 * 750B164 58 36 4«N 135 3^ 58W L L L 350. 1500 L L 20.00 75DB165 58 36 57N 135 33 24W L L L 300 1250 1 L 15.00 750B166 58 36 54M 135 33 22W L L L 250 1250 1 L >20.00 * 750B170 53 37 14N 135 25 59W L L L 300 1000 1 L 5 '.00 75DB171 53 37 24M 135 27 08U L L L 150 700 1 L >20.00 7500172 58 36 40N 135 28 43W L L L 150 700 2 L 3.00 41 75DB174 58 42 02N 135 54 53W L L L ion 325 L L >20.00 75DB175 58 41 55N 1 35 54 20W L L L *5 200 L L >20.00 54 40 * 750P176 58 41 53N 135 22W L L L 200 L L >20.00 ro 750B177 58 41 57N 135 53 42W 0.5 L L 12S 300 L L >20.00 i 75DB179 58 41 44N 135 53 20W L L L 85 200 L L 20.00 * o 75DB180 58 41 47N 1 35 53 29W L L L 125 500 L L >20.00 <-n 750B181 58 41 47N 135 53 1 4W L L L ?no 490 1 L 11.00 750B1?2 58 41 09N 135 52 59W L L L mo. 250 L L >20.00 * 750B183 58 41 46N 135 52 39W 1 .7 L L 175 250 L L 3.00 75DB1R4 58 41 33N 135 54 30W L L L 60 325 L L >20.00 <4> 750B1R5 58 41 13N 135 54 28W L L L 60 250 L L 18.50 750B191 58 44 16N 135 54 48W L L L 1 75 ?00 1 L 20.00 7506193 58 44 25N 135 53 30W L 150 1 75 L >20.00 * L L L 750B194 58 44 SON 135 53 39W L L L 250 400 1 L 6.00 75DB197 58 44 24N 135 52 37W L L L 300 500 1 L 2.50 * 75DB204 58 43 58C 135 53 19W L L L 175 200 L L 6,00 75DD206 5* 45 0°N 135 57 09W L L L 200 600 L L >20lOO 750P209 5« 46 251*.' 135 55 49W L L L 200 500 L L 8.50 * 75DP211 58 46 35N 135 54 50W L L L 200 1 75 L L >20.00 75DB213 5.Q 46 09K' 135 58 53W L L L 125 22'50 L L 5.00 W 750B215 58 46 4QN 135 59 29W L L L 300 700 1 L 7.00 750B225 5« 55 1 IN 136 31 1 3W L L L 60 200 L L >20.00 750B229 58 55 1/.N 136 28 OOW L 150 L >20.00 * L L 250 L 7 SOP 231 58 55 24N 136 28 32W L L L 75 250 L L >20.00 750B232 58 53 47N 136 30 29W L L L ;M 100 L L >20.00 *rf 7 50 R 234 58 5? 45N 136 29 54U L L L 20 100 L L >20.00 7506235 58 53 It *N 136 29 29w L L L 23 100 L L >20.00 75DB2<7 58 53 33fi 136 29 09W L L L IP 1 0" L L >20.00 * i 75DP238 51 5 7 31N 136 29 1 2W L I. L 75 1 75 L L >20.00 75DP242 *»? 51 18N 136 27 25W 100 >20.00 W L L L 1 50 L L Table 0-5.--Anomalous and distinctly anomalous stream-sedircent samples collected by the Geoloqical Survey.-continued Sample Cd < ppro) Co (ppm ) Cr (ppir.) Cu (ppm) Fe (X) La (ppm) *9 (X) Mn (pom Mo (ppm) Nb (ppm) 75DB158 L 60 110 1 75 8.50 70 7.00 1750 L L 75DP159 L '.0 85 1 ? 5 10.00 70 7.00 1500 L L 75DB160 L 25 60 125 8.50 70 7.00 1500 L L 7506161 L 30 60 1 ?5 8.50 70 7.00 1500 L L 75DR162 L 30 125 100 1 0.00 70 7.00 1500 L L 75DB163 L 30 85 70 8.50 mo 6.00 1500 L L 75DB164 L 40 100 100 10.00 70 6. no 1500 L L 75DB165 L 50 150 125 12.50 75 7.50 1000 L L 75DB166 L 60 100 70 12.50' 70 7.00 1500 L L 75DB170 L 125 150 10.00 70 7.00 2000 L L 750B171 L 1 3 60 70 5.00 85 4.00 1500 L L 75DB172 L 25 50 175 8.50 85 3.00 1750 L L 75DB174 L 15 35 50 5.00 60 3.00 1500 L L 75DB175 L 13 20 50 4.00 50 2.50 1500 L L 750B176 L 18 20 60 5.00 40 4.00 1500 L L 750P177 L 30 R5 70 6. on 70 2.00 1500 L L 75DP179 L 13 18 60 3. 00 50 ?.oo 1000 L L 75DB180 L 25 50 60 6.00 60 3.00 1500 L L 75DB1P1 L 40 85 100 6.00 70 3.00 1750 L L 75DB182 L 13 35 60 4.00 50 3.00 1000 L L 75D61R3 L 60 100 100 8.50 70 3.00 2500 L L 75D6184 L 30 43 125 6.50 60 3.00 2000 L L 75DB1R5 L 23 18 60 6.00 50 2.50 1500 L L 75DB191 L 40 85 70 6.00 60 3.00 2500 L L 75DB193 L 30 85 60 7.00 40 4.00 1000 L L 75DB194 L 40 110 125 8.50 60 6.00 1500 L L 75DB197 L 70 150 200 12.50 70 4.00 1500 L L 75DB204 L 40 100 70 8.50 35 3.00 1000 L L 75DB206 L 60 150 85 15. 00 50 5.00 2000 L L 75D6209 L 70 225 100 m.oo 60 4.00 1750 L L 75DB211 L 70 110 1 10 «.50 60 6.00 1750 L L 75DB213 L 85 250 150 1 ?.50 50 5.00 ?000 L L 7509215 L 70 12S 17S 12.50 60 6.00 1750 L L 750B225 L 10 30 '.0 4.00 50 4.00 1500 L L 75DB??9 L 9 25 100 4.00 60 6.00 1500 L L 75DB231 L 18 25 70 3.50 40 6.00 1250 L L 75DPP32 L 5 1 3 1 3 2.00 25 10.00 1000 L L 75DP234 L 8 1 8 1 fi 2.00 25 8.50 1000 L L 75DB235 L 5 1 R 3? 2.00 25 7.00 700 L L 75DB237 L 5 1 3 1 5 1.50 *5 10.00 1000 L L 75DR238 L 13 '.0 SO 2.50 40 3.00 1250 L L 7 5 D P 2', 2 L 20 20 50 7.50 40 6.00 1750 L L 0- S.-^nomalous and distinctly anomalous s t re am-spd i «» Same Ie N i ( pp m ) Pb (pom) Sh (ppnt) Sc < nom ) Sn (oom) S r (ppm ) T i (X) V (ppm) W (ppm) Y (ppm) 85 L 30 L 700 >1 .000 too 70 '0 L 50 50 L L mon > 1 .000 300 L 50 750R1.SO 70 60 L 30 L f»50 > 1 .000 300 L 40 7 5 D B 1 6 1 70 70 L 30 L *5Q >1 .000 300 L 40 75DP162 70 L 30 L 850 >1 .000 400 L 40 75DH16? inn 45 L 30 L 1000 >1 .000 400 L 75DF164 150 50 50 L 30 L 700 >1 .000 700 L 60 75DR165 1?5 60 L 40 L 500 >1 .000 600 750H166 L 60 85 35 L <0 L 1500 >1 .000 400 L 75Db17(j 135 40 m 60 L 40 L 200 > 1.000 700 L 60 75DP171 60 75 L L 1 500 1.000 250 L 75DR172 70 30 50 L 30 L 700 >1 .000 300 L 75DP174 45 30 30 L 18 L 1 500 0.300 150 L 75DB175 40 20 40 L 1 5 L 1 100 0.300 150 L 75DB176 25 15 30 L 1 3 L 2500 0.400 175 L 18 75DB177 do 85 30 L ?0 I. 600 0.400 75DB179 200 L 25 30 25 L 1 3 L 1500 0.300 150 75D8130 L 15 o 60 25 L 18 L 1500 0.400 -j 75DP181 100 ?00 L 25 50 L 30 L 175 >1 .noo 300 L 75DB182 40 ?5 40 L 1 5 L 1 500 0.300 175 L 18 75DB133 100 100 L 30 L 125 >1 .000 300 L 40 75 DO 184 45 40 L ?0 L 135Q 0.900 225 L 75DR1S5 23 40 40 L 15 L 1750 0.650 ?50 L 23 75DB191 100 50 L 25 L 400 0.750 250 L 25 75DP193 100 20 L 25 L 400 0.850 250 L 35 75DH194 135 50 L 40 L 200 > 1.000 400 L 50 75DP197 1 50 50 L 50 L L >1 .000 500 L 60 750B204 150 40 L 30 L L >1 .000 300 L 30 75DB206 150 20 L 50 L 700 >1 .000 500 L 70 75DB2°9 150 25 L 40 L 350 > 1 .000 400 L 40 75DB211 1PO 35 L 40 L 850 >1 .000 300 L 30 75DB213 175 60 L 60 L 400 >1 .000 600 L 60 75DB215 125 ?0 L 40 L 600 >1 .000 500 L 50 750B??5 40 18 L 15 L mno 0.400 175 L 20 75DB2?9 40 20 L 1 5 L «5Q 0. 300 175 L 30 75DP231 60 18 L 1 5 L 1500 0. 300 175 L 20 75DPP32 15 L L 6 L 700 0.200 100 L 13 75DBP34 ?5 L L 8 L 600 0.200 110 L 10 75DH?35 20 L L 9 L 850 0.200 125 L 13 7 5 D P ? 3 7 10 L L 5 L 600 0. 200 100 L 13 75 DP?38 60 25 L 1 5 L 1 ?50 0. 300 175 L 20 75DPP42 25 15 L 25 L 600 0.750 400 L 25 Table B-f$ --Anoma I ous and distinctly anomalous stream-sediment samples collected by the Geological Survey, -cont i nued I Sample Zn (ppm) Zr (pom) Au (ppm) Cu (ppm) Hq (ppm) Pb (ppm) Zn (ppm) 750B158 L 300 68 0.05 30 145 75DB159 L 400 55 0.03 25 90 75DB160 L 300 55 0.04 28 95 75DB161 L 300 50 0.06 25 90 75DB162 L 600 55 0.07 28 90 75DB163 L 300 0.07 2.3 75 75DP164 L 300 45 0.09 ?3 105 75DB165 L 300 50 0.10 25 90 75DB166 L 250 40 0.08 30 60 75DB170 L 200 ' 65 0.15 28 125 75DB171 L 150 40 0.05 20 55 75DF172 L 250 65 0.07 20 83 750B174 L 425 28 0.07 ?0 40 75DB175 L 100 ?8 0.04 33 40 75D0176 L 125 35 0.08 40 65 ro 75DB177 L 125 43 0.05 30 55 75DB179 L 85 35 0.08 33 48 00 75DB180 L 150 33 0.04 33 40 75DR181 L 250 58 0.09 38 105 750B182 L 100 40 0.07 33 50 75DB183 200 200 78 0.08 60 145 75DB1P4 L 185 38 0.16 35 60 75DB1P5 L 100 40 n .14 38 63 75DP191 L 125 68 0.35 38 85 750B193 L 175 0.11 30 50 75DP194 L 300 55 0.06 25 80 75DP197 L 300 68 0.23 30 85 75DP204 L 300 38 0.17 20 60 750P206 L 250 38 0.12 25 70 75DB209 L 250 48 0.09 25 83 75DB211 L 150 50 O.H9 28 65 75DB213 L ?50 60 0.22 38 145 75DP215 L 200 °,0 0.08 ?3 93 75DB225 L 125 25 0.01 38 40 75DB229 L 150 30 0.1? 30 50 75DB231 L 125 35 0.07 33 45 75DB232 L 25 20 0.06 35 20 75t>B?34 L ?5 20 0.04 40 23 L 100 1 8 0.07 40 30 75DH237 L 90 18 0.04 40 20 75f)E!23F L 100 35 0.11 38 105 L 0.1 1 30 90 Table 0- -5. --Anoma lous and distinctly anomalous stream-sediment samples collected by the Geological Survey, -cont i nued Sample La t i tude Longitude Aq (ppm) As (DOIT) Au (opm) B (ppm) Ba (ppm) Be (pom) Bi (ppm) Ca (X) 750B244 58 51 47N 136 27 12W L L L 85 250 L L >20.00 * 750B245 58 51 44M 136 27 08W L L L 75 200 L L > 2 0.00 75DB249 58 49 45N 136 24 47W L L L ?0 300 L L >20.00 750B251 58 50 13N 136 23 41 W L L L 125 250 L L >20.00 ift 75DH254 SR 51 27M 136 23 OOW 1.2 L L 125 600 L L >20.00 750P257 5 * 51 3PN 136 22 45W 0.6 L L 70 500 L L >20.00 75DR267 58 53 34N 136 23 53W L L L 60 700 L L >20.00 750R275 58 57 17N 136 48 1 1W L L L S7 500 L L 10.67 7500276 *»8 58 09 ft 136 48 21W L L L 30 600 L L 12.50 * 750P27f 58 58 5HJ 136 48 36W L L L 35 600 L L 10.00 750B?05 58 38 39N 135 29 1 2W L L L 250 850 L L 3.00 75oe?07 58 38 47fJ 135 32 55W L L L 175 850 L L 5.00 m 750B709 5H 41 1 5N 135 36 30W 0.6 L L 200 1000 1 L 15.00 750R310 5-? 41 17N 135 36 23W L L L 250 1000 L L 10.00 a 75DB111 58 40 35N 135 36 12W 0.8 L L 200 850 L L 17.50 W 750P312 58 4P 31 N 135 36 21U L I. L 300 1000 1 L 7.00 75DPM3 58 40 18N 135 35 59w L L L 250 850 L L 20.00 * s 750P315 58 40 09N 135 35 47U L L L 350 1000 1 L >20.QQ vD 7506*17 58 39 37 N 135 35 16U L L L 200 700 1 L 11.00 7506719 58 38 31 W 135 36 31W L L L 200 850 L L 2.00 * 75DH340 58 20 45N 136 17 32W L L L 150 500 L L 15.00 750B344 58 24 09N 136 27 30U L L L 125 300 L L 8.50 * 750G504 58 40 15N 137 41 38W L L L 10 100 L L 3.00 75KBP.01 58 28 06 N 135 30 30W L L L 1 50 400 1 L 3.00 75KB005 58 26 51 M 135 29 3?W L L L 175 300 1 L 2.00 * 75ff>009 S8 25 37N 135 28 31 W L L L ' 100 250 L L 6.00 75KBP10 58 25 0»N 135 28 09W L L L 1?5 2?5 1 L 5.00 75KROS9 5? 22 45N 136 33 32W L L L 60 1 00 L L 3.00 75KPC60 5« 22 4»M 1 36 33 50W L L L 40 85 L L 3.00 ^ 75KRT62 S^ 22 58fv 136 34 20W L L L ?0 75 L L 4,00 75KEIP65 ST 23 Q ?, M 1 36 33 40W L L L 3S 1 50 L L 3.00 S a m r I e (com ) Co ( pom ) C r (pom ) C u ( n D m) La (oom) Mq (X) Mo (opm) Nb 75DF 244 L 1 *o1 30 60 50 6.00 1500 L L 75DD245 L 35 70 7.00 25 6.00 2000 L L 75DR249 L 20 2S 40 c> .on ?5 >10.00 1000 L L L 25 60 70 s.fjo 35 >10.00 1000 L L 75DP254 L 15 70 4. on 60 4.00 1500 L L 750B257 L 23 25 75 7.50 45 3.00 2000 L L 75DP267 L 13 ?5 185 s.oo 30 3.00 1500 L L 750H275 L 27 62 183 10.67 50 1.83 1667 L L 75DP276 L 20 25 50 7.00 75 2.50 T500 L L 75DB278 L 25 50 40 8.50 60 2.00 1500 L L 75DB705 L 90 65 100 7.00 60 6.00 1500 L L 75DB?07 L 150 40 85 7.00 50 5.00 1?50 L L 7500309 L 25 125 70 6.00 70 4.00 1000 7 L 75DR310 L 25 100 70 5.00 75 4.00 1250 L L 750831 1 L 65 60 70 5.00 85 4.00 1000 7 L 75DB312 L 30 100 70 5.00 P5 3.00 1500 L L 7506313 L 30 85 70 5.00 75 4.00 1250 L L 75D6315 L 25 125 85 6.00 85 4.00 1250 L L 75DR317 L 85 50 70 5.00 50 3.00 1000 L L 7500319 L 30 100 100 5.00 70 3.00 1500 L L 75D634G L 40 85 110 7.00 50 4.00 3000 L L 75DP344 L 60 50 40 7.00 60 2.50 2500 L L 75DG504 L 60 400 50 8.50 L 3.00 2500 L L 75KPP01 L 40 70 70 7.00 70 1.50 >5000 L L 75KB005 L 25 265 100 7.00 60 1.50 2000 L L 75KB009 L 25 50 70 6.00 70 1.75 2000 L L 75KBP1C L 20 50 70 5.00 70 1.75 1750 L L 75KPC14 L 23 85 100 5.00 50 1.75 1500 L L 75KHP17 L 25 50 225 6.00 60 3.00 2500 L L 75KBOie L 25 45 100 7.50 70 2.50 1500 L L 75KPP59 L 50 150 40 5.00 L 2.50 1500 L L 75KDP60 L 70 17S 60 s.on L 3.00 1750 L L 75K8062 L 60 110 110 7.00 L 3.00 1000 L L 75KGP65 L 40 150 45 6.00 23 2.00 1000 L L 75KBP66 L 18 40 25 1 .50 1000 L L 75KQP67 SO 1SO 125 s.oo 20 2.50 1500 L L 75KPP70 10 10 40 1 .75 40 1 .00 700 L L Table 8- 5.--Anomalous and distinctly anomalous stream-sediment samples collected by the Geological Survey.-continued Sample Ni (pom) Pb (ppm) Sb (ppm) Sc (ppm) Sn (ppm) S r (ppm ) Ti CD V (pom) W (ppm) Y (ppm) 75DB244 50 20 L 15 L 1000 0.300 ?00 L 25 75D8245 50 18 L 30 L 700 0.700 300 L 30 75DBP49 25 L L 1 5 L 350 0.350 175 L 18 75DB251 60 15 L 1 8 L 500 0.300 175 L 18 750B254 70 25 L 25 L 1 500 0.700 400 L 40 75DB257 23 13 L 30 L inoo > 1.000 350 L 40 7508267 50 18 L 20 L 1500 0.400 400 L 30 750B275 15 L L 20 L 733 >1 .000 700 L 43 7508276 13 L L ?5 L 750 0.850 250 L 40 750B278 25 L L 25 L 850 > 1.000 400 L 50 7508305 70 AO L 30 L 400 >1 .000 300 L 50 75DB307 85 30 L 30 L ?50 > 1.000 300 L 30 75D8309 100 50 L 30 L 600 > 1.000 300 L 40 750B310 85 50 L 30 L 200 1.000 300 L 50 75DB311 £5 60 L 25 L 500 0.850 250 L 30 w 75D8312 100 50 L 25 L 175 1.000 300 L 40 75DB313 100 50 . L 25 L 400 0.850 ?50 L 40 750B315 100 50 L 30 L 600 1.000 350 L 10 750B317 85 40 L 25 L 350 0.700 200 L 25 750B319 85 60 L 30 L 1 25 1.000 300 L 40 7508340 70 18 L 50 L 600 1.000 300 L 50 750B344 40 13 L 30 L 500 0.850 250 L 40 750G504 85 L L 60 L 100 > 1.000 300 L 60 75KB001 100 18 L 30 L 125 1.000 300 L 50 75X8005 70 20 L 25 L 100 1.000 300 L 75KB009 70 15 L 23 L 350 > 1.000 250 L 30 75KB010 70 50 L 25 L 175 0.850 200 L 40 75KB014 60 23 L 23 L 700 0.650 175 L 25 75KB017 70 20 L 25 L 700 1.000 250 L 30 75KB018 85 20 L 23 L 500 > 1.000 250 L 30 75KBO?0 70 30 L 25 L 500 0.850 250 L 30 75KB022 R 5 23 L ?3 L 450 0.750 250 L 40 75KB026 38 108 L 30 L 850 > 1.000 400 L 40 75K8057 65 10 L 30 L 175 0.600 250 L 5 75K8058 135 L L 50 L ?50 0.500 250 L 8 75K8C59 70 L L 25 L 1 75 0.300 175 L 5 75KBC60 85 10 L 30 L 200 0.250 175 L 5 75KB062 85 L L 40 L 200 0.400 300 L 5 75KBOA5 85 L L 40 L ?50 0.650 250 L 20 75KB066 18 L 15 L 200 0. 200 125 L 20 75KB067 85 13 L 18 L 300 0.650 175 L 20 75KB070 8 25 L 10 L 1 75 0.225 100 L 30 Table B- 5,--Anoma lous and distinctly anomalous stream-sediment samples collected by the Geological Su rvey.-cortt < nued I Sample Zn (ppm) 1r (pom) Au (oprn) Cu' (ppm) Hq* (pom) Pb" (ppm) Zn' (ppm) 75D82AA L 200 L 30 O.OR 30 115 75DB2A5 L 125 L ?3 0.08 33 105 75DB2A9 L 175 L 23 0.18 33 28 750B251 L 65 L AO 0.15 33 AO 75DBP5A L 175 L A3 0.10 ?3 103 75DP257 L 175 L 28 0.08 20 AO 75DP267 L 150 L 33 O.OA 23 103 75DB275 L A67 L 28 0.06 12 22 75DB276 L 825 0.21 25 0.03 10 25 75DB278 L 300 0.15 25 0.05 fi 25 75PB305 L 250 L 58 0.10 20 85 750B307 L 200 L 53 0.10 23 88 75DP509 L 250 L 50 0.13 *0 1 AO 75DB310 L 175 L 55 0.11 28 95 750B31 1 L 250 L 50 0.13 30 135 td 75DB312 L 250 L A8 0.12 23 120 750B313 L 175 L 55 0.16 33 155 75DB315 L 225 L 50 0.15 28 115 75DB317 L 150 L A3 0.11 30 103 75DB319 L 175 L 68 0.15 25 100 75DB3AO L 225 B A3 0.26 18 50 75DB3AA L 500 L ?5 0.27 13 A3 75DG50A L 18 L 30 0.03 5 18 75KB001 L 175 L 33 0.35 15 A5 75KP005 L 200 L 50 0.28 15 93 75KB009 L 175 L AO 0.36 15 65 75KBP10 L 150 L 53 0.58 33 93 75KD01A L 1?5 L 108 0.27 38 65 75KD017 L 250 L 230 0.17 15 180 75KB018 L 200 L 85 0.11 20 165 75KB020 200 175 L 73 0.12 23 1 AS 75KP022 L 125 L AO 0.33 8 38 75KB026 L AGO L A3 O.OA 20 83 75KB057 L 35 L 25 0.26 5 30 75KB058 L 10 B 0 0.32 B R 75KBC59 L 13 B 0.30 L 23 75KB040 L 15 B B 0.31 B B 75KB062 L 5 L 155 0.33 13 55 75KB065 L 40 L ?8 0.31 8 AO 75KB066 L 25 L 10 0.28 8 18 75KB067 L 65 B 70 0.29 10 38 75KB070 L AO L 5 0.?5 L 5 Table (3- 5.--Anomalous and distinctly anomalous stream-sediment samples collected by the Geoloqical Survey.-cont i nued Samnle Latitude Longitude Ag (pom) As (ppm) Au ' (ppm) Ra (opm) Be (ppm) Bi (opm) Ca (X) 75KBP71 58 26 2 8N 136 31 12U L L L L 400 5 L 0.70 76AF091 58 23 59N 137 04 30U L L L 30 20 L L 8.50 76AFP92 58 23 57.N 137 04 34U L L L 30 20 L L 7.00 76AFP93 58 25 06N 137 05 35W L L L 20 L L L 00 76AFP94 58 25 06N 137 05 28W L L L L L L 7.00 76AFP95 58 28 02N 137 07 41U L L L. 25 30 L L 7.00 76AF096 58 28 33N 137 06 05U L L L 30 30 L L 6.00 76AFP97 58 24 33.M 137 05 OOU L L L ?5 L L L 7.00 76AF102 58 25 43M 137 10 24U L L L 18 L L L 7.00 76AF103 58 26 15N 137 11 34W L L L 50 L L L 1.10 76AF106 58 26 15N 137 08 12W L L L 40 30 L L 6.00 76AF107 58 26 25N 137 09 46W L L L 15 45 L L 7.00 76AF113 58 29 1 2N 137 10 OOW L L L ?0 25 L L 6.00 76AF11 7 58 29 48N 137 13 22U L L L 85 700 L L 0.70 76AF119 53 27 07N 137 13 46U L L L 30 20 L L 3.00 w 76BJ019 58 13 44M 136 37 42U L L L 50 700 L L 1.75 76BJ042 58 18 32N 136 43 35W L L L 40 250 L L 7.00 76BJ116 58 38 45N 137 27 58W 0.6 L L 20 50 L L 2.50 OJ 76BJ118 58 37 32N 137 25 56W L L L 175 700 L L 1.35 76BJ120 58 39 04N 137 26 49W L L L 15 100 L L 5.00 76PJ121 58 39 07N 137 26 58U L L L 15 125 L L 4.00 763J122 58 39 52N 137 ?8 1 7W L L L 18 200 L L 3.00 76BJ126 58 40 3?N 137 31 09W L L L 18 85 L L 5.00 76BJ128 58 40 57N 137 34 36W L L L 85 400 L L 3.00 76PJ1 35 58 41 09 f.' 137 41 46U L L L 35 125 L L 3.00 76CN119 58 39 OAN 137 28 19W L L L 10 1 50 L L 5.00 76DRP32 58 17 32N 136 35 28W L L L P5 500 L L ,00 76DBT33 58 16 31N 136 34 1 6U L L L 100 850 L L ,00 76DB036 58 17 5CN 136 37 OOW L L L 50 600 L L ,00 76DB04? 58 20 03N 136 43 52U L L L 25 400 L L ,00 760BP52 58 18 50N 136 46 17W L L L 20 700 1 L ,50 760B053 5* 18 22N 1 36 46 40U L L L ?5 600 L L ,50 76DB058 58 2? 59N 136 47 06U L L L 60 500 L L ,00 760B063 58 25 1PN 136 46 35W L L L 30 400 L L ,00 760P067 58 27 0«N 136 50 10U L L L 10 700 L 3.00 76DBC7C 58 27 13N 136 52 40W L L L 400 L 00 76DRT74 58 24 43N 136 48 5fiW L L L 15 200 L 00 76DBC84 58 25 15N 136 52 22W L L L 13 1 50 L , 00 7 6 D B p 8 5 58 23 45N 1 36 54 07W L L L 1 50 L 00 76DPP86 SK 2? 59K' 136 54 54W L L L L L 10 76DHOP7 5* 24 4?K/ 136 53 57W L L L 35 30 L 5.00 7 6 D P 0 8 fr ^8 25 18N 136 53 1 3W L L L 25 30 L 6.00 w Table Q- 5.--AnomaIous and distinctly anomalous stream-sediment samples collected by the Geological Survey.-continued Sample Cd (ppm) C o (opm ) C r (ppm ) Cu (ppm) Fe (%) La (ppm) Mg (X) Mn (ppw) Mo (ppm) Nb (ppm) 75KB071 L 5 10 L 1 .00 60 0.10 500 L 76AFP91 L '.00 L 30 !", 5 6.00 L 5.00 1500 L 76AF092 L 50 ?no <<5 L 10.00 L 5.00 1750 L L 76AF093 L 35 600 75 6.00 L 4.00 2000 L 76AF094 L '.5 600 L 7.50 L 4.00 2500 L L 76AFC95 L 30 400 7.00 L 4.00 2000 76AF096 L L L 35 500 110 7.50 L 5.00 1750 76AF097 L L L 40 700 85 8.50 L 5.00 1750 76AF102 L L L 25 500 85 5.00 L 5.00 1750 76AF1P3 L 70 1500 L L 60 15.00 L 2.25 3250 L L 76AF106 L 60 400 185 7.00 L 3.00 76AF107 3000 L L L 25 400 50 5.00 20 5.00 1750 76AF113 L L L 40 300 '00 7 0^ L 3.00 2000 76AF117 L 25 175 L L 70 s!oo 20 1.50 1500 L 76AF119 L 60 850 L 30 8.50 L 5.00 1750 L L 76BJ019 L 15 100 50 ?.50 60 1.50 1500 tt» 768J042 L L L 20 300 25 5.00 20 5.00 4000 76BJ116 L 100 L L 600 300 10.00 L 2.00 2000 L 76BJ118 L 25 250 L 300 ,50 20 1.50 1500 L L 76BJ120 L 30 300 125 00 L 2.00 1500 L L 76BJ121 L 30 300 125 00 L 2.00 1500 L 76BJ122 L 20 L 125 150 00 20 1 .50 1750 L 76BJ126 L 35 200 L 85 3.50 L 2.00 1500 L L 76BJ128 L 9 10 ?0 1 .50 L 1.50 1750 9 L 76BJ135 L 50 300 125 S.50 L 2.00 3000 L L 76CN119 L 30 500 100 .00 L 3.00 1500 760BC32 L 25 L L POO 60 .00 ?5 3.00 3250 5 * 76DBP33 L 25 L 200 60 .00 30 2.50 ?000 L 760Bf)36 L L 20 150 50 .50 30 1.75 2000 L 760P048 L 20 175 L * 60 ,00 ?0 2.00 1750 8 L 76DBP52 L 15 85 40 ,00 70 1.75 1750 9 76DBP53 L 20 L 110 60 .00 25 2.00 3500 5 76DBOS8 L ?5 L 300 70 ,00 ?5 4.00 ?000 L L 7606063 L 85 100 70 ,00 25 1.75 >5000 L 76DB067 L 18 60 L 40 2.00 70 1 .50 1500 L L 76DBP70 L 15 85 40 3.25 70 1.50 3?50 L L 76DPP74 L 25 350 50 5.00 L 3.00 1750 L I 760BP84 L 25 150 1 50 5.00 20 2.50 3000 L L 760B085 L 35 450 70 7.50 L 5.00 4000 L L 760BOR6 L 325 1 5 12.50 L 3.00 4000 L L 760B087 L 50 150 150 L 4.00 1500 L 76DI3088 L 40 L 175 150 7.00 L 3.00 2000 L L Table B-S.--Anoma lous an-J riistinctly anomalous stream-sediment samples collected by the Geological Survey.-cont i nued Sample Mi (ppm) Pb (pom) Sb (ppm) Sc Cppm) Sn (pom) Sr (ppm) Ti (X) V (pom) W (ppm) Y (ppm) 75KB071 5 50 L L 76.AF091 L L 0.070 L L 40 L L 30 25 L 100 > 1.000 200 L 76AF092 60 L L SO 20 L 100 > 1.000 250 L 76AF093 40 L L 30 25 76AFP94 L mo 0.900 135 L 15 50 L L 25 L 100 > 1.000 125 L 20 76AF095 60 L L 40 76AFT96 L 200 > 1.000 150 L 40 L L 30 25 L 300 > 1.000 150 L 13 76AF097 60 L L 40 L 200 >1 .000 200 L 76AF102 50 L L 30 20 L mo > 1.000 150 L 76AF103 60 L L 25 20 L 200 > 1.000 175 L 15 76AF106 70 L L 30 L 200 >1 .000 200 L 76AF107 50 L L 30 13 76AF113 L 200 1.000 150 L 110 L L 40 20 76AF117 L 100 > 1.000 200 L 60 18 L 1 5 30 76AF119 L 100 > 1.000 150 L 70 L L 30 25 L L > 1.000 200 L 20 76BJ019 30 20 L 20 500 W 76BJC42 L 1.000 150 L 20 50 L L 30 76BJ116 L 400 0.900 150 L 150 L L 50 20 76BJ118 L 150 > 1.000 150 L 85 13 L ?5 30 76BJ120 L 300 >1.000 150 L 25 100 L L 30 L 200 1.000 175 L 30 76BJ121 100 L L 40 76BJ122 L 200 1.000 200 L 50 10 L 30 30 76BJ126 L 300 1.000 150 L 85 L L 40 30 76BJ128 L 200 0.850 225 L 25 18 L L 15 L 500 0.500 100 L 18 76BJ135 85 L L 40 L 150 >1.000 200 L 40 76CN119 70 L L 25 760B032 L 1 75 >1 .000 150 L 20 50 10 L 20 760BC33 L 500 > 1.000 175 L 30 60 18 L 20 76DRT36 L 300 >1.000 150 L 30 25 18 L 25 76DB048 L 500 > 1.000 175 L 25 60 18 L 20 L 500 0.850 200 L 18 76DP052 40 25 L 18 7606053 L 400 1.000 200 L 25 50 20 L 18 76DB058 L 250 > 1.000 200 L 25 60 L L 40 7606063 L 300 > 1.000. 175 L 40 60 20 L 18 76DB067 L 300 0.750 200 L 18 18 30 L 15 L 300 0.500 150 L 25 76DB070 35 15 L 18 76D8074 L 300 1.000 175 L 25 50 L L 30 760PCR4 L 300 > 1.000 200 L 50 L L 30 23 760PPS5 L 300 > 1.000 200 L 30 75 L L 50 76DBOR6 L 1 75 >1 .000 225 L 45 50 L L ?3 L L >1 .000 200 L 25 760B087 L L 40 760B088 L 1 75 >1.000 200 L 30 f 5 L L 30 L 1 50 >1.000 250 L 30 Table 8- '5. --Anomalous and distinctly anomalous stream-sediment samples collected by the Geological Survey. -cont i nued Sample Zn (ppm) Zr 76AF106 L 15 L 68 * 76AF107 L 30 L 0.05 10 25 83 O.OA 76AF113 L 60 L 5 10 280 0.05 76AF117 L 70 L 5 25 ?,o 0.06 £ 76AF119 L AO L 18 215 50 0.05 5 15 td 76BJ019 L 125 L 23 0.31 18 70 0 I 76BJOA2 L 60 L 1F 0.03 8 35 £ 76BJ116 L 9Q L 120 0.03 C* 76BJ118 L 85 L 7 23 75 0.06 18 0 768J120 L 70 L 1 25 160 0.03 L 15 768J121 L 70 L 8S O.OA A 768J122 L 125 L L 20 73 O.OA L 30 w 76BJ1P6 L 60 L 150 76BJ1PS L AO L L L 10 8 L L 20 $ 76BJ135 L 25 L 85 0.05 8 AO 76CU119 L 70 L 115 0.02 L 18 (A 76PB032 L 125 C.A1 A3 0.09 V 7600033 L 150 L 8 A5 25 0.28 13 76Dpp 56 L 125 L 70 28 0.29 8 A3 . 76DBD48 L 60 L *5 0.07 8 53 L 125 L 20 0.37 10 ,* 76D&053 L 150 L AO ?8 O.A3 15 W 76DBC58 L 175 L 73 28 0.09 L 76D6P63 L 85 L 25 63 0.1? 13 7» ^ 760P067 L 1?5 L 33 0.07 13 95 76DP070 L 125 L 38 0.0*5 10 AO «| 76DP07A L 100 L 33 0.09 76Pnf°A L 85 L 10 33 1 AO 0.10 3 20 76DB0R5 L 65 L 55 O.OA 76nOf«6 L 10 L 5 25 25 O.OA L 10 7 L ?0 L 175 0.07 L 23 76DHPPE L 60 L 1 AO O.OA L 8 Tatle B-5.--Anoma I ous and distinctly anomalous stream-sediment samples collected by the Geoloqical Survey.-c ont i nuerl Saroole. La t i t ude Lonqitude Aq (pom) As (ppm) A u (o p m) B (ppm) 8a (ppm) Be (ppm) 8i (ppm) Ca (Z) 76DB089 5« 25 54N 136 5? 55W L L L ?5 40 L L S.OO 76DBC95 58 26 27N 136 55 51W L L L 10 60 L L 5.00 76DB101 59 25 04N 136 58 26W L L L m 1 25 L L S.OO 76DB102 58 26 44N 136 57 30M L L L 10 150 L L 5.00 A 76D6103 58 27 07N 136 57 27W L L L 10 60 L L S.OO 76DB104 58 27 48N 136 56 59W L L L L 75 L L 5,00 76DB105 58 24 45N 137 00 48W L L L 10 20 L L 50 m 76DB106 53 25 22N 136 59 23W L L L 10 60 L L 00 76DB110 58 25 46N 137 01 49W L L L 18 50 L L 00 m 76DB1 11 53 25 58K' 137 04 43W L L L 30 L L 00 76DB112 58 26 01N 137 04 41W L L L 85 25 L L 5.00 760R177 53 45 47N 137 42 05W L L L 150 700 L L 3.00 ** 760B179 58 45 03N 137 40 19W L L L 85 400 L L 3.00 76DB180 58 43 34N 137 42 19W L L L 100 300 L L 3.00 m 76DB1R1 58 44 08N 137 41 22W L L L 40 50 L L 6.00 7 6 D B 1 P. 2 58 43 28N 137 41 09W L L L 60 1 50 L L 5.00 f 76DB184 58 45 55N 137 45 41W L L L 100 1 75 L L 6.00 m M 760B185 58 45 53N 137 43 57W 1.3 L L 100 700 L L 5.00 I^ 76DB199 58 30 37N 137 23 56W L L L 20 1 50 L L 7.00 m 76DBPOO 58 31 25N 137 25 01W L L L 55 700 L L S.OO 760B202 58 32 18N 137 26 44U L L L 50 1 50 L L 76DB204 58 33 06N 137 28 29W L L L 50 400 L L ,00 0 76DB21 2 53 44 27N 137 49 44W L L L 70 125 L L ,00 76DBP17 . 58 40 21N 137 41 42W L L L 35 58 L L ,85 76DB220 53 48 35N 137 39 51W L L L 18 20 L L ,00 » 76DB2P3 58 45 37N 137 35 31W L L L 13 30 L L 7.00 76DD224 53 47 01 N 137 36 19W L L L 13 L L L 7.00 4^ 760BP47 58 52 33N 137 44 43W L L L 20 40 L L 7,00 76DB248 58 53 10N 137 46 1 7W L L L 1ft 50 L L 7.00 76DP249 58 53 4/.N 137 46 57W L L L 45 1 00 L L 5.00 » 76Dfc?50 5« 54 07N 137 45 40W L L L 100 70 L L ,00 76DBP52 53 52 3?N 137 49 36W L I. L 50 1 50 L L 00 ^ 76DB256 58 53 UN 137 53 25W L L L 10 85 L L ,00 7600257 58 52 26N 1 37 55 38W L L L 1 3 60 L L ,00 76DFP5? 58 47 07N 137 55 44W L L L 50 700 L L ,00 76DP26C 5« 51 ?4N 137 51 52W L L L 50 300 L L 5.00 58 51 46H 137 5? 59W L L L 60 1 75 L L 3.00 « 00*2 OO'S GO'S 0V 292HU9Z OSZl 00 '^ 001 S2V OS (J92U09Z OOSl OO'l OO'Z OOS 00 V Oi 3S2J09Z 0091 OO'S 00' OSl OSZ Of ^S2'd09Z 0001 00*5 00' SZ2 OOZ OS 9S2 309Z S8'0 OOOS< 00'2 00*9 09 01? 0V 00' OS2 o/ 0002 00*2 1 SZl SZl 00* 09 OOS2 OS'l Ot S21 S8 ov OSZl O0'£ 1 00' 001 001 S2 2113Q9/ OSZl 00*£ GO'V OSl S22 UIQ09/ OOSl 00*£ 1 OO'Z OU2 S21 OS 01 1009Z 0002 00'^ 02 OS'S Sbl OS2 cs OSZl OO'i 1 oo'si OS OOS 09 SG1009Z OSZl OO't 02 Cti'Z S2I. S22 Of 0002 UO* V 1 00'Z 002 OS OOSl 00'^ 1 OS'Z OSl OS2 09 201Q09/ os*i UO* V GS'fc s.21 OSJ 09 OStf UO'S GO'V OO'V Wl S22 OS 0002 00 ' i SZl GJ2 GS (u»dd) ow (mad) (ji n a ) 03 ( moo > 03 1*3100,0*9 Xq sno, c -Q Table D- 5. -- Anoma I ous and distinctly anomalous stream-sediment samples collected by the Geological Survey. - corit 1 nued Sample (prm) Pb (ppm) Sb (ppm) Sc (nom) Sn ' (opro) Sr (opm) m V (ppm) W (pom) Y (ppm) 76DROP9 mn L L 30 L 1?5 >1 .000 200 L 30 ?5 L L 40 L ?no 76W101 125 > 1.000 200 L 30 L L SO L 175 >1.000 760P102 100 L 200 L 30 L 50 L 175 > 1.000 200 L 76DB103 mu L L 70 30 L 1 ?5 > 1.000 200 L 50 760P104 70 L L 50 L 125 > 1.000 200 L AO 60 L L 40 L L > 1 .000 175 L 40 760B106 70 L L so L 100 > 1.000 175 L 60 760B110 70 L L 70 L 100 >1 .000 200 L 70 760811 1 70 L L 50 L 100 > 1.000 175 L 25 76DB112 30 L L 70 L 100 0.850 ?00 L 30 760B177 70 25 L 30 L ?00 76DP179 60 0.750 300 L 30 L L 40 L ?00 1 .000 76DB180 60 10 300 L 30 L 50 L 400 0.850 200 L 76DD181 150 L L 30 60 L 300 0.575 225 L 25 760B182 125 L L 60 L 300 0.500 760B184 60 175 L 25 L L 60 L 3CO 1 .000 250 76DB185 100 L L 40 L 30 L 1000 1.000 250 760B199 125 L L 40 L 60 L 250 > 1.000 200 L 40 760BPOO 100 10 L 50 L 500 > 1.000 200 L 30 7600202 30 L L ?5 L 150 76DB2C4 > 1.000 150 L 25 18 10 L 15 L 400 760B212 > 1.000 150 L 20 60 L L 50 L 1 75 760B217 53 > 1.000 ?00 L 50 L L 39 L L >1 .000 175 L '760RP20 70 L 20 L 50 L 100 0.700 ?00 L 30 760B?23 75 L L 50 L 100 0.600 150 L 30 76D0224 70 L L 60 L 100 760B247 100 0.600 175 L 30 L L 60 L 100 1.000 250 76DB248 35 L 30 L L 50 L 100 1.000 250 7600249 100 L L 30 L 40 L 150 1.000 ?00 L 30 76DB250 60 L L 40 L mo 0.750 175 L 30 760B252 40 L L 1 8 L 150 760B?56 150 0.200 125 L 18 L L 50 L 125 >1.000 150 760B257 150 L L 25 L SO L 1?5 >1.000 200 L 30 7600258 175 L L 50 L 225 >1.000 200 L 25 76DP?60 100 L L 50 L 400 >1.000 200 L 30 76DB262 85 L L 30 L ?00 M.OOO 200 L 30 Table U- 5. --AnomaIous and distinctly anomalous stream-sediment samples collected by the Geological Survey.-continued Saroole 7n 2 r (PPTI ) Au (opm) Cu (pom) HO (pom) Pb 760P089 70 L 1 ?5 0.06 L 5 76DP095 100 L 1 50 o.os L 10 mo L 0.06 10 20 76DP102 100 L 14H 0.13 8 25 76DP103 85 L 110 0.04 L 760P104 100 L 160 0.04 5 15 76DB1P5 10 L 63 0.05 L 13 760P136 85 L 1 25 0.04 L 10 7609110 70 0.29 0.05 L 30 760B111 30 L 100 n.04 L 8 760B11 2 L 40 L 165 0.06 L 15 76DB177 L 85 L 93 0.25 20 135 760P179 L 100 L 135 0.22 15 85 760B1PO L 150 L 43 0.27 13 60 7608181 L 35 L 55 0.18 5 25 76081P2 L 30 L 100 0.09 10 60 760P184 225 70 L 33 0.17 10 48 760R1P5 300 P5 L 75 0.30 15 180 10 O 760B199 L 60 L 93 0.05 L 10 760B200 L 85 B 140 0.08 10 45 760B202 L 33 L 20 0.0? L 18 76DR204 L 110 L 1 5 n.02 5 38 76DP212 L 30 0.21 38 0.05 10 38 760B217 L 105 L 15 0.09 L 8 76DB220 L 50 L 115 0.04 5 10 760D223 L 60 L 93 0.03 5 13 760B224 L 30 L 95 0.03 L 5 76PB247 L 50 L 190 0.04 L 23 7608248 L 50 L 140 0.04 5 18 760P249 L 85 L 65 0.02 L 30 760B25C L 60 L 150 0.0* L 25 76DR252 L 40 L 70 0.23 18 175 7606256 L 40 L 11 5 L 5 13 7608257 L 85 L 120 0.0? L 13 760825P L JOO L ?55 0.12 13 78 760B260 L 100 L 63 0.07 10 73 76DB262 L 150 20 0.15 10 35 ® L * Analyses oy atomic absorption/ all others by semi quantitative spectrograohic methods. Rocks The geochemical analyses of a given bedrock unit reflect the background metal composition of the unit; that composition may differ markedly from rock unit to rock unit. Thus, a certain value for a given element in a sample in one rock unit may be anomalously high, but would be only average in another rock unit. Because of this variation in the background level from unit to unit, it is desirable to treat and interpret the elemental abundance pattern for each rock unit separately. Due to the poor bedrock geochemical sample distribution (plate 2), there were too few samples in many rock units to treat them separately. A comparison of histograms and statistical summaries indicated some of the map units were geochemically similar. Therefore, the 20 rock units shown on the geologic map were consolidated into six bedrock geochemical units. These six units are 1) hornblende-bearing metamorphic rocks, 2) layered gabbros, 3) granitic rocks, 4) graywacke and argillite, 5) mafic dikes, and 6) others. The relations between these bedrock geochemical units and the map units shown on plate 1 are given in table B-6. Treatment of rock data was similar to the procedure described TABLE B-6 NEAR HERE above for stream-sediment data, except that each rock geochemical unit was treated individually. B-121 Table B- 6. Rock units from plate 1 contained in rock geochemical units Rock geochemical unit Rock units Description Hornblende-bearing mg Schist and gneiss with dominant metamorphic rocks hornblende Layered gabbro gb Layered gabbro bodies Granitic rocks Tg, TKg, Kg All granitic intrusive rocks plus granitic portions of associated migmatites Graywacke and argillite DSsg Devonian-Silurian graywacke and argillite units ro H* Mafic dikes DSsg Mafic dike samples within DSsg Others Ty, Ttc, Ky, Pap, Pirn, Pug, Remaining rock units; most with Pzh, Pzm, Pzg, DSug, DSc, few bedrock geochemical samples mgp, ms "Descriptions of individual rock units shown on plate 1. An anomalous level was then defined for each element in each of the bedrock geochemical units; these threshold levels (table B-7) were TABLE B-7 AND FIGURES B-8 to B-19 NEAR HERE determined by a process similar to that used for the stream-sediment samples at the 95th percentile. The histograms used to determine those levels are shown in figures B-8 to B-19 . Table B-8 contains the analytical data and brief descriptions of 410 bedrock geochemical samples which TABLE B-8 NEAR HERE meet or exceed the threshold level in one or more elements. These sample locations are plotted and identified by sample number on plate 2. Plots of all the analytical data for each individual element are available in Johnson (1978). Following these manipulations, distribution patterns of important elements were analyzed to determine their economic significance, if any; these interpretations are given below. B-123 Table B-7. Anomalous levels in parts per million for selected metals in bedrock geochemical samples as used on plate 2 and figures B- 8 to B-19 Hornblende -bearing Layered Granitic Graywacke and Mafic Element metamorphic rocks gabbro . rocks' argil lite dikes Others Ag 1 1 1 ! Co 100 150 100 100 Cr 800 700 300 300 300 Mo 15 ___ __ 15 Ni 200 950 70 100 200 100 Pb 30 50 70 40 Sn 15 15 ___ 1 c. W 150 150 Au1 . 05 .05 .05 Cu1 300 800 100 100 100 150 Hg1 .1 .1 .1 .1 Zn1 150 150 150 Analyses by atomic absorption, all others by semiquantitative spectrographic method. t§.«- -i Granitics Layered (Jabbro 1 - to Hornblende Graywacke & Meta. Argillite .38 m o .5 I Mafic Dikes Others too .78 .8 .3 10 CON C. (PPM) Figure B-8. Histograms of the distribution of silver in each rock-geochem- ical unit. Analysis by semiquantitative spectrographic methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-125 Granitic Layered Gabbro 35 JTJI 10 20 10 1 5 100 too 1000 Hornblende 40- Graywacke & Meta. Argillite 30-1 m to £0 o 10 B 6 100 5 30 Others 40 Mafic Dikes ts to 10 5 100 * too CONC. (PPM) Figure B-9. Histograms of the distribution of cobalt in each rock-geochem- ical unit. Analysis by semiquantitative spectrographic methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-126 c 4 20* 10 10 too 1000 10 too 1000 Hornblende Graywacke & Meta. Argillite 50- 20- Ln 10 100 1000 B 10 100 Mafic Dikes to- Others 25- 20 10 10 too a to too IOOO CONC. (PPM) Figure B-10. Histograms of the distribution of chromium in each rock-geochem- ical unit. Analysis by semiquantitative spectrographic methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-127 Granitic Layered 7.1 loo- Gabbro i- 5 10 B 5 Hornblende Graywacke ft Meta. too Argillite m o n B 5 10 Mafic Dikes too Others &< / ^ 4 - too CONC. (PPM) Figure B-11. Histograms of the distribution of molybdenum in each rock-geo- chemical unit. Analysis by semiquantitative spectrographic methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-128 Granitic Layered Gabbro 30- 30- 20' I zo- 10 10 J-U-] B 5 100 100 1000 6 Hornblende Grqywacke S Met a. Argillite 30- 30 m 20- 20- Ln o 10 10 B 9 100 1000 B 10 100 Mafic Dikes Others 30' 30- £0- 20- 10 10 too 100 1000 CONC. (PPM) Figure B-12. Histograms of the distribution of nickel in each rock-geochem- ical unit. Analysis by semiquantitative spectrographic methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-129 "T3 Granitic too- Layered Gabbro SO 10 10 IOO 10 Hornblende 6.7- Graywacke 8 t L5--i Meta. ! Argillite 4 jl i * : rh 'f i 15 - 2.' 10- 5- B 10 30 a 10 100 Mafic Dikes 47.t Others IS 10 Ul iio too t 10 CONC. (PPM) Figure B-13. Histograms of the distribution of lead in each rock-geochemi- cal unit. Analysis by semiquantitative spectrographic methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-130 Granitics Layered Gabbro 100- n B 10 too Hornblende Graywacke ft 100--f Meta. 100--I Argiilite m o Mafic Dikes Others IOO-H I. - n 8 100 CONC. (PPM) Figure B-14. Histograms of the distribution of tin in each rock-geochemi- cal unit. Analysis by semiquantitative spectrographic methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-131 Granitic Layered ice- IOO--T Gabbro 150 Hornblende Graywapke B too--i Meta. Argillite KX> 30 m o Mafic Dikes Others too- -i too 3OO CONC. (PPM) Figure B-15. Histograms of the distribution of tungsten in each rock-geochem- ical unit. Analysis by semiquantitative spectrographic methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-132 Granitic Layered Gabbro K>0 S J05 J Hornblende Graywacke 8 Met a. too Argillite m o .06 .1 t .os Mafic Dikes Others 96.6 3 -I .1 - B .09 .1 CONC. (PPM) Figure B-16. Histograms of the distribution of gold in each rock-geochemi- cal unit. Analysis by atomic absorption methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-133 Granitic Layered Gabbro 50 40 20 BT52 B .02 Hornblende Graywacke 8 5« Meta. Argjllite 50- -n 40 7 PM m O 25 20 1 n B .02 .1 .02 .1 Mafic Dikes Others 50 40 ton B .02 . I O2 CONC. (PPM) Figure B-17. Histograms of the distribution of mercury in each rock-geochem- ical unit. Analysis by atomic absorption methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit" of detection. B-134 20' Granitic Layered Gabbro so 10 J1 20 10 B 5 too IOOO 10 too IOOO Hornblende Graywocke B Argiliite Tl :U rn o 25' Jiif n n 100 i 1000 B 5 100 B 5 Mafic Dikes 20- Others 50- \]\ 23 1 n 10 100 B 5 lOO IOOO CONC. (PPM) Figure B-18. Histograms of the distribution of copper in each rock-geochem- ical unit. Analysis by atomic absorption methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detection. B-135 - .r u Granitic Layered n Gabbro 90 15 ' 10 § s 10 too 510 160 Hornblende Graywacke S Meta. Argitlite t5 25 m o 10 10 B 5 10 100 B 5 10 100 Mafic Dikes Others 50- _n 25 10 B 5 K> too f 10 100 CONC. (PPM) Figure B-19. Histograms of the distribution of zinc in each rock-geochemi- cal unit. Analysis by atomic absorption methods. Values to the right of the vertical dashed line are anomalous as defined in this report (see table B-7). Samples plotted as "B" were below the limit of detec tion. B-136 Table 9-^.--AnomaIous bedrock qeochemical samples collected by the Geological Survey. Sampl e Lati tude Longi t ude Aq (ppm) As (pi Au (ppm) B (ppm) 8a (ppm) Be (pom) Bi (ppm) Ca * 66AF312 58 24 48N 136 33 12U N* N N L J 300 7 N 0.15 66CH5138 58 25 32N 136 37 01U N N N L 20 N N 1.50 * 66CH575B 58 34 43N 136 34 34W N N N L L N N 2,00 66JS052 58 54 48N 136 35 48U N N N L ?n N N 1.50 - 66T0282 58 47 18N 136 04 24W N N N 10 L L N 0.70 75BJ0620 58 44 14N 135 59 38W N N N 30 300 N N 3. 00 75BJ064A 58 43 19N 136 02 48U N N N 50 700 N N s. no & 758J064B 58 43 19N 136 02 48W N N N 70 700 N N 5.00 75BJ0688 58 41 55N 136 24 10W N N N N 150 N N 15.00 75BJ068C 58 41 55N 136 24 10W N N N L 100 N N 3.00 ® 75BJ0680 58 41 55N 136 24 10W N N N L 100 N N 3.00 75BJ069B 58 41 47N 136 24 45W N N N 50 500 N N 3.00 $> 75BJ071A 58 42 32N 136 25 40W N N N 30 1000 L N 3.00 753J072C 58 55 UN 136 55 45W N N' N 5n 200 L N 3.00 m 75BJ0720 58 55 14N 136 55 4SW N N N sn 3 on L N 3.00 75BJ074A 58 58 20N 136 56 40W N N N ?o 500 L N 2.00 ta 75BJ0748 58 58 20N 126 56 40W N N N 20 700 L N 3.00 © i 1 75BJ078A 59 00 42N 137 00 15W N N N 3n 700 1 N 1.00 U) 75BJ078B 59 00 42N 137 00 15W N N N 50 1000 1 N 1.no 75BJ078C 59 00 42N 137 00 15W 15.0 >ionon L 10 100 1 70 0.30 ^ 758J0780 59 00 42N 137 00 15W 20.0 >iooon L in ino 150 0.50 75BJ100A 59 04 15N 136 11 45W N N N 15 700 N 5.00 & 75BJ1008 59 04 15N 136 11 45W N N N ?o 700 N 10, on 75BJ122I 58 28 44N 137 04 40W N N N m 30 N 5.00 75BJ1238 58 32 57N 136 59 38W N N N L 20 N 7.00 75BJ123C 58 32 57N 136 59 38W N N N L 20 N 7.00 75BJ1230 58 32 57N 136 59 38W N N N m 50 N 7.00 75CC077B 58 51 SON 135 58 SOW L N N inn 300 N >20.no 75CC0770 58 51 SON 135 58 SOW 1.0 N N ion 100 N 2.00 £ 75CC078B 58 51 32N 136 00 30W N *l N 10 1500 N 10.00 75CCP948 59 05 DON 136 49 59W N N N 50 700 N 15.00 75CC094D 59 05 DON 136 49 59W N M N ?n 700 N m.oo 0 75CC095A 59 03 49N 136 48 19W N N N 70 300 N 15. nn 75CC096A 59 03 18N 136 46 55W K< N N 70 300 N ?n.oo » 75CC0968 59 03 18N 136 46 55W N N N 70 200 N 7. no 75CC097B 59 03 03N 136 46 19W N N N sn 200 N >20.00 75CC097C 59 03 03M 136 46 19W N M Sample Cd (ppm) Co (ppm) C r (ppm) Cu (pnm) Fe La (opffl) Mg (X) (ppm) M o (ppm Nh (ppm) 66AF312 N 5 N L 0.50 N 0.03 700 N N 66CH513H N 30 30 100 s.oo N 3.00 500 N N 66CH575B N 30 150 50 5.00 N 3. on 1000 N N 66JS052 N 30 30 150 5.00 N 1 .50 700 N N 66T0282 M 15 300 1 5 ?.oo N 3.00 500 N N 75BJ062D N 70 100 50 7. on L 3.00 1500 N N 758J064A N 50 2C 70 5.00 N 3.00 1500 N N 75BJ064B N 30 ?0 70 3.00 ?0 3.00 1000 N N 75Bjn688 N N 10 5 0.50 20 1.00 500 N N 758J068C N 50 300 70 3.00 N 3.00 1000 N N 75BJ0680 N 20 100 50 2.00 L 3.00 1000 N N 75BJ0698 N 50 10 50 7.00 L 3.00 1000 N N 758J071 A N 30 20 SO 5.00 20 2.00 1000 N N 75BJ072C N 10 1 5 50 2.00 20 2.00 1000 N N 75RJ0720 N 30 20 30 5.00 20 3.00 1500 N N 75BJ074A N 15 30 20 ?. on 20 2.00 700 N N 75BJ074B N 30 30 30 7.00 20 3.00 1000 N N 758J07RA N 5 20 20 1 .50 L 1.50 700 N N 00 75BJ0788 N 10 20 15 1 .50 20 1.50 ?no N N 759J078C N 200 L 150 5.00 N 0.50 300 N N 75BJ0780 N 200 10 150 5. on N 0.50 3no N N 75BJ100A N 15 150 30 5.00 20 3.00 1000 N N 758J100B N 30 100 70 3.00 30 2.00 1000 N N 758J122I N 70 200 100 7.00 L 3.00 1500 N N 75PJ1238 N 100 700 70 s.oo N 5.00 mno N N 753J123C N 100 700 70 7.00 N 5.00 inno N N 75BJ1230 N 100 1 500 150 3. no N 5.00 1500 N N 758J123E N 50 700 70 ?.oo 20 5. on 1500 N N 75BJ125B N 70 1000 150 7.00 L 5.00 1000 N N 75CC077.A N 100 300 100 7. on 30 5.00 ?000 N N 75CC0770 N 70 200 70 7.00 50 3.00 2000 N N f* 75CC0770 N 150 70 150 >?o.on L 1 .00 500 50 N 75CC0788 N 10 10 L 3.00 50 3.00 1500 N N 75CC0948 N 30 150 L 7. no 50 5.00 2000 N N 75CCP94D M 70 10 100 10.00 L 3.00 2000 N N 75CC095A N 20 1 5 30 5.00 30 3.00 ?onn N N 75CC096A N 30 30 50 5. on 20 3.00 1500 N N 75CC096Q N 30 1 5 70 7.nn 20 3.00 2000 N N 75CC097B N 20 70 50 5.00 30 3. on 1500 N N 75CC097C N I 20 10 1 .on N 1 .50 1000 N N 75CC097H N 10 L 150 1 .50 L 0.70 7no N N 75CC101C N 70 ?on 100 10.00 50 7.00 2ono N N Table B-8.--AnomaIous bedrock qeochemical samples collected by the Geological Survey.-continued Sample Ni (ppm) Pb (opm) Sb (opm) Sc (opm) Sn (ppm) Sr (com) Ti (X) V (pom) U (ppm) Y (ppm) 66AF312 L 10 N L N N 0.015 L N 15 66CH513B 50 N N 30 N 200 0.300 200 N 10 66CH575B 100 N N 20 N 300 0.300 150 N 15 66JS052 70 N N 15 N 300 0.500 150 N 15 66T02S2 70 N N 15 H L 0.150 70 N 10 75BJ062D 100 L N 30 N 500 0.700 200 N 30 . 75BJOA4A 30 L N 15 N 700 0.300 150 N 10 75BJC64B 20 L N 20 N 700 0.300 200 N 15 75DJ068B 5 10 N N N 300 0.020 10 N L 75BJ068C 150 N N 20 N 300 0.300 150 N 15 75BJ068D 70 N N 20 N 300 0.200 100 N 10 75BJ069B 15 L N 20 N 700 0.500 200 N 20 75BJ071 A 10 L N 15 N 500 0.500 150 N 30 75BJ072C 5 10 N 15 N 700 0.200 100 N 15 75BJ0720 15 30 N 20 N 1000 0.500 150 N 30 W 75BJ074A 10 N N 15 N 500 0.300 150 N 15 M 75BJ074B 30 L N 20 N 700 0.500 150 N 20 {g 75BJ07PA 5 10 N 5 15 500 0.150 70 N 10 753J078B 10 10 N 5 15 700 0.150 50 N 10 75BJ078C 20 100 N 5 15 N 0.100 20 N N 75BJP78D 20 150 N 5 30 N 0.100 20 N N 75BJ100A 100 20 N 20 N 500 0.300 200 N 20 75BJ 100B 150 20 N 30 N 700 0.500 300 N 30 75BJ122I 150 N N 50 N 200 1.000 300 N 20 75BJ123B 150 N N 50 N 200 0.300 300 N 10 759J123C 150 N N 70 N 200 0.300 700 N V 10 75BJ1230 200 N N 150 N N 0.700 1000 N 20 75BJ123E 100 N N 70 N N 0.300 300 N 15 75BJ125B 200 N N 50 N 200 0.500 300 N 15 75CC077A 100 20 N 50 N 1000 1 .000 300 N 50 75CC077B 150 15 N 50 N 1000 1.000 300 N 50 75CC077D 200 70 N 20 N ?00 0.500 200 N 10 75CC07PB 5 10 N 30 N 1000 0.500 150 N 20 75CC094B 70 L N 50 N 1000 1 .000 300 N 30 75CCO'UD 70 N N 50 N 1000 1.000 500 N 30 75CC095A 5 L N 30 N 1000 0.700 200 N 20 75CC096A 20 L N 30 N 1500 0.700 200 N 20 75CC096B 30 L N 30 N 1000 1 .000 300 N 30 75CC0978 30 70 N 20 N 1500 0.300 150 N 30 75CC097C 10 20 N S N >5000 0.050 30 N 10 75CC097H L 20 N 5 N 7HO 0.200 50 N 10 75CC10U 200 N N SO N 1500 >1 .000 300 N 30 Table P-8.--AnomaIous bedrock oeochemical samples collected by the Heoloqical Survey.-continued Sample Zn (ppm) Z r (ppm ) Au (ppm) Cu (DPT) Hq (pom) Pb (ppm) Zn (pom) Li tholoqy 66AF312 N 20 L R 10 25 alask i te 66CH513B N N 160 R 10 10 hornblend i te 66CH575B N 50 90 R 10 15 unclass. dike 66JS052 N 30 23C P 10 A5 Iamprophyre 66T0282 N 10 25 R 15 AO unclass. dike 750JP62D N 100 35 0.1A 15 65 andes i te 75PJ06AA N 20 N 65 0.12 10 25 diori te 753J06AB N 20 N 85 0.1 A 10 20 d i o r i t e 75BJ068B N 10 N 10 0.10 55 H 20 Ii mestone 75BJ068C N 20 N «5 n.16 5 10 hornfeIs 75BJ0680 N 20 N 75 0.18 5 10 hornfeIs 75BJ069B N 20 N 25 0.12 5 35 hornfels 75BJ071 A N 200 N 35 0.10 5 10 di ori te 75BJ072C N 70 N AO 0.1? 15 75 hornfeIs 75BJ0720 N 100 N 25 0.12 15 85 hornfeIs W 75BJ07AA N 50 N 25 0.10 5 A5 di or 1te M 75BJ07AB N 100 N 1 5 0.1? 5 A5 diori te £ 75BJ078A N 100 N 15 0.2? 10 60 quartz diorite 75BJ078B N 20 N 20 0.20 15 50 ouart z di ori t e 75BJ078C N 10 0.55 1 AO 0.20 ?AO 1 30 aoli te 759J0780 200 10 1.00 1AO 0.12 ?90 190 aoli te 75BJ100A N 150 N 35 0.06 10 10 argillite 75BJ100B N 150 N 60 O.OA 10 20 arciillite 75BJ122I N 50 0.05 85 0.04 H L amphiboli te 75BJ123B N L N 65 0.06 10 20 qabbro N* 75PJ123C N 10 55 O.OA 5 15 qabbro 75BJ1230 N 10 N 1?0 O.OA L 10 ult rama fi c 75BJ1?3E N 10 N 120 0.06 L 15 ultrama fie 75BJ125B N 15 N 130 0.06 5 5 qabbro 75CCP77A N 150 N 50 0.08 ?0 25 greenstone 75CC077B N 150 N A5 0.16 15 15 unclass. volcanic 75CC0770 N 30 N 85 0.10 60 30 hornfeIs 75CC078B N 200 N L 0.10 5 20 tonalite 75CC09AB N 150 N N 0.06 10 35 ouartz diorite 75CC09AO N 150 N 65 0.08 5 30 diori te 75CCO<*5A N 20 N 10 0.12 10 50 quartz diorite 75CC096A N POO N 20 0.12 10 35 diori te 75CC096B N 150 N 30 0.1? 10 30 diorite 75CC097B 300 100 N 25 O.OP 65 H 130 cale-siIicat* 75CC097C N 10 N 10 0.10 A5 H 10 marble 75CC097H N 150 N 90 O.OA 10 20 alask i te 75CC101 C N 300 N 55 0.1? 10 50 unclass. dike m 41 Table B--8.--Anoma I ous bedro * Samp I e Lat i tude Longi tude Ag (ppm) As (pom) Au (ppm) (ppffl) Ra (ppm) Be (opm) Bi (com) Ca (*> 75CC102B 58 24 24N 135 27 20U N N M 20 300 L N 7.00 41 75CC105F 58 56 46N 136 18 28U N N N 200 50 L N >?0.00 75CC105J 58 56 46N 136 18 28U N N N 100 200 1 N 10,00 75CC105L 58 56 46N 136 18 28U N M N L 300 L N 1.00 75CC1050 58 56 46N 136 18 28W N N N 100 500 N N 10.00 75CC105P 58 56 46N 136 18 28W N N N 100 200 N N 7,00 75CC105R 58 56 46N 136 18 28U N N N 50 300 L N 15.00 75CC106C 59 01 23N 136 57 02W N N N ?n 500 L N 10.00 75CCin7C 58 54 02N 136 15 40U N N N 50 100 L N 15.00 <* 75CC1070 58 54 02N 136 15 40U N N N 100 30 N N 20.00 75CC130D 58 20 18N 136 44 SOW N N N 50 1500 1 N 3.00 0 75CN106A 58 53 57N 136 16 29W N N N 15 300 L N 5.00 75CN108A 58 54 01N 136 15 32W 10.0 N N L 20 N 100 L 75CN109A 58 53 59N 136 15 26W N N N 150 700 1 N 0.50 * 75CN113A 58 53 43N 136 12 41W N N N 10 700 1 N 3.00 tn 75CN118C 58 41 17N 136 42 38U N N N 50 200 N N isloo M 75CM127A 59 00 44N 135 52 56W M N N N 1000 2 N 1.50 M 75CN1278 59 00 44N 135 52 56U N M N N 700 1 N 0.70 75CN131A 58 52 SON 136 33 49W N N M 15 30 N N 10,00 75CN131B 58 52 SON 136 33 49W N N N 10 70 N N 5.00 75CN134C 58 27 03N 136 51 20U N N L 300 L N 5.00 41 75CN143A 58 29 02N 136 48 12U N N sn 1500 L N 2.00 750B220A 58 43 39N 135 55 01U 1.0 N L 20 N N >20.00 750B294A 58 33 34N 136 33 OfiW N N 15 700 L N 7.00 * 75DB294C 58 33 34N 136 33 08W N N L 100 N N 15.00 750B295A 58 33 20N 136 32 40U N N 30 500 N N 10.00 * 75DB299C 58 32 18N 136 31 12W N N 15 3000 L N 3.00 . 75DB301A 58 31 40N 136 30 29W M N 30 500 N N 5.00 75DB325A 58 29 54N 135 33 38W N N 150 200 1 N 20.00 0 75083?5C 58 29 54N 135 33 38W N M 150 200 L N 20.00 75DB325D 58 29 54N 135 33 3SW N N 150 200 L N 15.00 * 75DB3?6B 58 30 39N 135 35 43U N N 150 300 L N 10.00 75DB327A 58 32 32N 135 36 03W N N 150 500 L N 7.00 75DB3278 58 32 32N 135 36 03W N N mo 300 L N 7.00 * 75DP330C 58 59 37N 136 24 34U N N 10 20 N N 7.00 75DB33CO 58 59 37N 136 24 34W N M L 20 N N 10.00 & 75DB330G 58 59 37N 136 24 34U N N 10 200 N N 10.00 750B33CH 58 59 37N 136 24 34U N M 10 150 N N 7.00 750B354H 58 25 S8N 136 47 58W N 10 200 N N 7.00 * 75DB354L 58 25 58N 136 47 58W N m 50 N N 7.00 75DB355A 58 25 4CN 136 47 44U N ?o 1500 1 N 2.00 & 75DB355G 58 25 42N 136 47 44W N 50 200 L N 7.00 GO'S OO'Z N N OOSl 02 OOS 002 0£ N o N N ouz OS' I 0£ OS' I s oos s N VSSfQdSZ N N (JUS I. 00*01 N 00*01 OO'S oz ooz OSl N > N N oosi 00*01 N 002 ooz oz N HVS£80SZ N N 0001 oo*z 1 UO'Z OS 001 N oo*z OO'Z ooz HO££80SZ N N OUS I N OS ooz N oo*z UO'Z oz N N 0001 N OS ooos 001 N aoiseosz OO'Z N N 0001 oo*z 1 OS 0002 N O0'£ U0*£ 001 N N 0001 01 OS N O0'£ OO'Z 001 01 N N 0001 02 oz OSl 01 N VZ2Z80SZ 00*£ OO'Z N N OOSl OS 02 N 00*£ UO'Z oz oz N N OOSl 02 oz OS 0£ N N N 00*£ 01 uo't oust 00*£ OO'S OS oz z N 3S2£8QSZ N N OOSL ot oz 02 02 N VS2£80SZ N N OOSl 00*£ 02 00*01 OS*l uu*z 001 S I ot N viotaasz N OOZ OOSl oo*s OS oz 02 Ok N 36o280SZ C N N OOSl ot OO'St OSl 1 001 N VS6280SZ UO'Z N N 0002 oo*z 02 OSl 002 OS N OO'Z OO'Z N N OOSl 02 02 ooz oz N W6290SZ N N OOSl 00*2 0£ OO'S 00*2 OO'S OOU02< 01 01 N V02280SZ N SI 000 I ot oz 001 01 N VSVIN3SZ 00*2 OO'S N N ooz 0£ 001 oz 0£ N oo*£ OU'Z N 0001 1 S I 001 OS N 8l£lN3SZ 00*£ OO'Z N OOSl 02 s USl OS N Wl£lN3SZ N 01*0 OS*G ooz 0£*0 OS 1 1 s N 8Z21N3SZ N ooz oo*s 001 00* I 1 01 N N VZ21N3SZ N OOSl N 00*02 oz oz 001 N 33UN3SZ OQ OS'l uO*£ N OOSl oz S I 1 N os*o 00*2 01 V£UN3SZ N N OOSl OS 1 1 s N V601N3SZ N 20*0 oz*o OOZ 1 OO'Z N OS 1 N N V801N3SZ N N OOSl 02 OO'Z OO'Z oz 001 OS N V901N3SZ N N OOSl 00 *£ oz OS 0£ 01 N 00£133SZ OO'S N N OG02 N OO'Ul GO'S OSl oz OS N CZ0133SZ N N 0002 02 OO'Z OSl O0'£ OO'Z oz OS N 3Z0133SZ N N 0002 02 oz OS oz N 390133SZ N N OOSl oo*s OS OO'Ol 00*£ oz OS oz N HS013DSZ N N 0001 02 uo'oi oz 001 oz N psnui juoa- 'X«A jn$ Xq sajdwes ) BD i uisq DOdb )(DOjpaq sno i euiouy-- g-a Table P-8.--Anomalous bedrock qeochemical samples collected by the Geological Survey.-continued Sample Ni (ppm) Pb (pom) Sb (opra) Sc Sn (OPT>) Sr (onm) Ti <*) V (pom) W 75CC102B 150 N N N 700 > 1.000 300 N 30 75CC105F 50 15 N 20 N 700 0.500 300 N 50 75CC105J 15 30 N 70 N 1000 >1 .000 300 N 100 75CC105L L 50 N N N 100 0.200 30 N L 75CC1050 100 15 N 50 N 500 > 1.000 3nn N 30 75CC105P 100 10 N 50 N 700 > 1.000 300 N 50 75CC105R 100 N N 50 N 1000 >1 .000 300 N 50 75CC106C 70 N N 50 N 1000 >1.000 ^00 N 30 75CC107C 100 N N 70 N 700 > 1.000 500 N 30 75CC107D 100 N N 50 N 500 >1.000 . 500 N 50 75CC130D 20 50 N N 7CO 1.000 300 N 20 75CN106A 70 N N 30 N 500 > 1.000 200 N 30 75CN108A N 30 N N N N L L 300 N 75CN109A L 30 N 5 N 300 0.500 mo N 15 75CN113A L 15 N 7 N 700 0.300 100 N 10 w 75CN118C 50 N N 50 N 1500 > 1.000 300 N 50 75CN127A L 50 N L N 200 0.150 30 N 10 CO 75CN127B 5 50 N 5 N ?00 0.200 20 N 10 7 5 C N 1 3 1 A 100 N N 30 N 200 0.700 300 N 30 75CN131B 100 N N N 200 0.500 200 N 20 75CN13AC 100 L N 15 N 1000 0.500 150 N 10 75CN1A3A 15 30 N 20 N 500 0.700 200 N 20 750R220A 10 10 N 20 N 500 0.150 100 N 15 750R29AA 200 N N 30 N 1000 0.500 200 N 20 750B29AC 150 N N 50 N 200 1.000 200 N 20 750B295A L N N 30 N 1500 0.500 200 N 30 750B299C 15 15 N 10 N 700 0.500 150 N 20 75DB301A 15 L N 30 N 500 1.000 200 N 50 750B325A 50 70 N 20 N 1000 0.300 200 N 20 750B325C 30 70 N 15 N 700 0.200 100 N 15 75DB3250 70 70 N 15 N 1000 0.200 150 N 30 750B326B 100 L N 30 N 300 1.000 300 N 50 75DB327A 100 N N 2P N 1 50 0.700 200 N 30 750B327B 70 N N 15 N 500 0.200 150 N 30 750B330C 300 N N 70 N 150 0.200 200 N 10 750B3300 300 N N 100 N 200 0.300 150 N 10 75DB330G 200 N N 30 N 700 0.700 300 N 20 750B330H 200 N N 50 N 700 0.500 200 N 20 750B35AH 300 N N 30 N N 0.100 150 N L 750B35AL 300 N N 70 N N 0.150 300 N 10 750B355A 5 30 N 7 N 500 0.200 70 N 10 750B355G 100 L N 30 N 200 0.200 500 N 15 * m Table B-8 . Anomalous bedrock geochemicaI samples collected by the Geological Survey.-continued m Sample Zn (ppm) Zr (opm) Au (oom) Cu 1 (ppr) Hq 1 (pom) Pb' (ppm) Zn' (pom) litholoqy 75CC102B N POO N 85 0.04 10 50 unclass. dike 75CC105F N 150 N 10 0.10 10 15 calc-silicate 75CC105J N 300 N 75 n.04 15 ?0 qabbro 75CC105L N 50 N 10 0.06 10 10 grani te 75CC1050 N 150 N 70 n.os 10 20 amphiboli t e 75CC105P N 300 N 55 0.02 10 25 amph i hoii t e 75CC105R N ?00 N 45 0.08 15 50 lamprophyre 75CC106C N 150 N 65 0.04 10 20 diori te 75CC107C N 150 N 140 0.02 10 45 greenstone 75CC107D N 150 N 150 0.10 10 40 qreens t one 75CC130D N 200 N 30 0.06 10 70 qne i s s 75CN106A N 150 N 75 n.io 10 70 unclass. dike 75CN108A N N N 1 5 0.10 50 L nuartzite 75CN109A N 150 N 10 0.24 15 30 qranodiori te 75CN113A N 150 N 10 0.10 10 40 qranodi or i te to 75CN118C N 50 N 40 0.06 10 45 diori te 75CN127A N 150 N L L 10 20 andesi t e 75CN1278 N 70 N 10 0.04 10 25 andes i t e 75CN131 A N 30 N 5 0.04 10 L di abase 75CN131B N 20 N 20 0.02 10 10 di aba se 75CN134C N 150 N 70 0.04 5 35 Quartz diorite 75CN143A N 150 N 35 0.04 15 70 gnei ss 75DB220A N 10 N 12000 0.10 15 H 10 ma rble 75DB294A N 70 N 1 5 0.02 5 10 anphiboli te 75DB294C N 100 N 100 0.02 10 50 lamprophyre 75DB295A N 10 N 60 0.02 m 30 di ori te 75DB299C N 100 N 55 0.04 15 30 cataclast i te 75DB301 A N 100 N 35 0.02 5 45 tonaIi te 75DB325A N 100 N 40 0.04 40 H 65 si ate 75DB325C N 50 N 25 0.04 35 H 45 si ate 75DB32SD N 100 N 30 0.04 35 H 45 slate 75DB326B 200 150 N 50 0.02 15 H 60 qraywacke 75DB227A N 200 N 35 0.04 15 H 130 qraywacke 75DB327B N 100 0.05 30 0.06 15 H 100 qr aywack e 75DB330C N 20 N 30 0.04 15 25 qabbro 75DB330D N 10 N 30 0.02 15 25 qabbro 75DB330G N 70 n 35 0.04 10 30 qabbro 75DB330H N 30 N 35 0.04 10 30 aabbro 75.D6354H N L N 170 0.04 5 10 qabbro 75DP354* N N H 50 0.02 5 15 qabbro 75DB355A N 30 N 10 0.06 10 45 qnei ss 750B355G N 20 N 300 0.02 10 20 qnei ss w m m Table B-8..--Anomalous bedro m Sample La t i tude Longitude Ag (ppm) As (opm) Au (ppm) 6 (ppm) 8a (pom) Be (ppm) Bi (ppm) Ca (X) 75DB360A 58 25 30N 136 45 32W N N N 70 500 L N 5.00 ft 750B360B 58 25 30N 136 45 32W N N N 200 1500 1 N 3.00 750B363A 58 30 24N 136 46 22W N N N L 1500 1 N 2.00 750B363B 58 30 24N 136 46 22W N N N L 1500 2 N 1.00 ft 750B365A 58 29 57N 136 45 39W N N N L 1000 2 N 2.00 75DB365B 58 29 57N 136 45 39W M N N L 1500 2 N 5.00 ft 75DG501 A 58 51 48N 136 56 41W L N N L 500 L N 3.00 75DG503A 58 33 12N 136 55 48U 0.5 N N 15 100 N N 5,00 75DG503A 58 33 12N 136 55 48U 3.0 N N 10 200 N N 5.00 ft 750G503B 58 33 12N 136 55 48U L N N L L N N 0.70 75DG503C 58 33 12N 136 55 48U 2.0 N N L 20 N N 5.00 ft 750G503C 58 33 12N 136 55 48U 1.0 N N 10 30 N N 10.00 75DG5030 58 33 12N 136 55 48U L N N 10 30 N N 7.00 75DG5030 58 33 12N 136 55 48U 1.0 N N L 20 N N 7.00 ft 75DG503E 58 33 12N 136 55 48U 2.0 N L 70 L N N L 03 75DG503E 58 33 12N 136 55 48U 2.0 N N 150 N N N ., t- ^ 75KB007A 58 26 18N 135 29 19W N N N 10 300 L N 3.00 75KB023B 58 36 57N 135 54 18W N N N 50 20 N N 15.00 Ui 75KB0388 58 55 42N 136 17 40U N M N 10 700 1 N 0.70 ft 75KB046A 58 32 OON 136 24 45W N N M 30 1000 L N 3.00 75KB046B 58 32 OON 136 24 45W N N N 50 1000 L N 0^70 ft 76AF031B 58 13 03N 136 40 1 2U 1.5 N N 100 700 L N 2.00 76AF0468 58 20 OON 136 43 53W N N N 10 1000 1 N 3.00 76AF050A 58 23 41N 136 47 04U L N N 100 1500 1 N 3.00 ft 76AF056A 58 26 21N 136 46 55W N N N 10 200 N N 7.00 76AF0568 58 26 21N 136 46 55W N M N 10 200 N N 7.00 ft 76AF0648 58 17 44N 136 47 21W L N N L 100 1 N 5.00 76AF064C 58 17 44N 136 47 21W N N N L 100 1 N 3.00 76AF069C 58 19 56N 136 51 10W N N N 10 L N N 3.00 ft 76AF0690 58 19 56N 136 51 10W N N N 10 L N N 2.00 76AFG69E 58 19 56N 136 51 10W N N H m 30 N N 7.00 * 76AF069F 53 19 56N 136 51 10U N N N 10 20 N N 7.00 76AF078A 58 17 43N 136 38 10W N N N L L N 1.00 76AF078B 58 17 43N 136 38 10W N N N L L 2 N 1.00 ft 76AFC79A 58 17 32N 136 38 17W N N N L 700 2 N 2.00 76AF079B 58 17 32N 136 38 17W N N N L 1000 2 N 3.00 * 76AF082A 58 16 43N 136 38 10U N M N L 1000 3 N 2.00 76AF082B 58 16 43N 136 38 10U N N N 15 1000 1 N 3.00 76AF088B 58 22 05N 136 53 25W N N N 10 L L N 10.00 * 76BJ025A 58 19 18N 136 37 29U N N N 30 700 1 N 2.00 76BJ025B 58 19 18N 136 37 29W N N N 30 700 1 N 2100 ft 76BJ027B 58 12 OON 136 38 1 AW N N N 10 1000 1 N 3.00 Table B- 8. --Anomalous bedrock geochenHcal samples collected by the Geological Survey.-continued Sample Cd (ppm) Co (ppm) Cr (ppm) Cu (ppm) Fe (X) La (pom) Mg (X) (pom) Mo (ppm) Nb (p D n) 75DB360A N 20 100 200 5.00 100 1.50 1000 N N 75DB360B N 10 100 70 5.00 30 2.00 1500 N N 75DB363A N L L L 1 .50 30 0.20 500 N N 75DB3638 N N 10 L 1.00 30 0.20 1000 N N ft 75DB365A N N 10 L 1 .00 1 50 0.30 700 N N 75DB3658 N 10 10 L 5.00 50 1.50 1500 N N * 75DG501A N 7 15 100 1 .50 30 1 .50 1000 N N 75DG503A N 150 200 1500 7.00 N 3.00 1000 N N 75DG503A N 200 150 3000 7.00 N 5.00 1000 N N 75DG503B N 70 150 500 3.00 N 5.00 1000 N N 75DG503C N 50 200 700 2.00 N 5.00 700 N N 75DG503C N 150 300 1000 5.00 N 7.00 1000 N N 75DG503D N 70 300 700 5.00 L 7.00 1000 N N 75DG503D N 70 300 700 5.00 N 5.00 1000 N N 75DG503E N 1500 20 1 5000 >20.00 N 0.07 10 N N CO 75DG503E N 1000 15 10000 >20.r»0 N 0.30 L N N I 75 75KB0468 N 5 70 20 0.70 30 1.50 100 20 N 76AF031B N 20 100 30 3.00 20 2.00 1500 N N 76AF046B N 15 70 20 5.00 30 2.00 1500 N N 76AF050A N 15 100 100 5.00 30 2.00 1500 N N 76AF056A N 30 1500 30 5.00 ?0 5.00 1500 N N 76AF056B N 30 1500 30 5.00 L 5.00 1500 N N 76AF064B N 7 15 500 1 .50 30 1 .50 1000 N N 76AF064C N 7 10 150 1 .50 30 1 .50 1000 N N 76AF069C N 70 3000 70 7.00 N 7.00 2000 N N 76AF069D N 70 5000 300 10.00 N 10.00 2000 N N 76AF069E N 50 50 300 7.00 L 3.00 1500 N N 76AF069F N 70 70 300 7.00 N 3.00 1500 N N 76AF07&A N N 70 L 0.50 L 0.02 1500 N N 76AF078B N N L L 0.50 L 0.03 1500 N N 76AFD79A N N 10 L 0.70 50 0.30 700 N N 76AFP79B N L 15 L 1.00 70 0.50 700 N N 76AFOP2A N 5 10 L 1.50 50 0.70 1500 N N 76AF082B N 5 10 L 1 .50 70 0.50 700 N N 76AFOBCB N 20 20 1500 1 .50 20 3.00 1500 N N 76BJP25A N 15 70 30 ?.oo 50 1.50 1500 N L 76RJ025R N 20 100 50 3.00 30 1.50 1500 N L 76BJ027B N 15 150 50 3.00 50 2. no 1500 N N A * Tab B-8.--Anomatous bedrock qeochemical samples collected by the Geological Survey.-continued A Sampl p Ni (ppm) Pb (ppm) Sb (ppm) Sc (pom) Sn (ppm) Sr (opm) Ti <*> V (pom) U (oom) (com) 750B360A 50 30 N 15 N ?00 0.300 150 N ?0 750B360B 50 50 N 20 N 200 0.700 POO N 20 75DB363A L 50 N 10 N 100 0.070 10 N 30 750B363B L 70 N 5 N 1SO 0.050 10 N 15 II 750B365A L 50 N 5 N ?00 0.100 10 N 30 7508365B 5 50 N 15 N 200 0.500 50 N 15 75DG501 A 10 20 N 10 50 soo 0.200 70 N 15 750G503A 3000 L N 30 N 200 0.150 ?00 N 10 750G503A 5000 10 N 30 N 500 0.200 150 N 10 750G503B 300 N N 7 M N 0.030 50 N N 750G503C 700 L N 30 N 150 0.150 ?00 N 10 750G503C 3000 L N 50 N 200 0.200 300 N 10 750G5030 1000 N N 50 N 100 0.200 300 N 10 750G5030 700 L N 70 N 200 0.200 N 750G503E 300 15 >5000 N N N ?0 N 0.003 L N L w 750G503E >5000 N N N N 75KB007A L L N N « i 200 N N 20 500 0.700 150 N £> 20 75KB023B 50 10 N 15 300 150 -J 75 76AF056B 100 20 N 150 0.300 500 N 15 76AF06«0 10 L N 7 700 0.500 100 N L 76AF06AC 15 10 N 5 700 0.500 100 N L 76AF069C 2000 N N 20 N 0.150 70 N 10 76AF0690 * 2000 N N 15 N 0.150 70 N 10 76AF069E 150 N N 30 POO 1.000 300 N 15 76AF069F » 150 N N 30 200 1 .000 700 N 15 76AF078A 5 50 N 5 N 0.005 L N 30 76AF078B L 70 N 5 N 76AF079A 0.003 L N 30 0 5 70 N 7 100 0.070 10 N 50 76AF079B 5 50 N 7 100 0.150 76AF082A 15 N 30 W 5 70 N 7 1 50 0.150 30 N 30 76AF082B 5 70 N 10 150 0.150 76AF0888 20 N 30 300 N N 10 POO 0.150 50 N 10 TableTab B-8. Anomalous bedrock geochemical samples collected by the Geoloqical Survey.-continued ** Sample Zn (ppm) Zr (ppm) Au (ppm) Cu (ppm) Hq' (pow) Pb (ppm) Zn' (pom) Lithology 75DB360A N 150 N 110 0.06 10 45 qneiss 75DB360B N 200 N 40 0.9'. 10 85 qnei ss 750B363A N 100 N L 0.02 5 30 grani te 75DB363B N 100 N 5 0.0? 5 25 granite 75DB365A N 100 N 5 N 5 25 granite 750B365B N 150 N 5 0.04 10 30 qrani te 75DG501A N 70 N SO 0.04 15 60 skarn 750G503A N 10 N 1600 0.04 10 5 pyrox*nite 75DG503A N L B B 9 B B pyroxeni te 75DG503B N L N ROO 0.02 15 65 pyroxenite 750G503C N N N 830 0.02 10 5 pyroxenite 750G503C N L B B B B B oyrox^ni te 75DG5030 N L B B 8 B B pyroxeni te 750G503D N 10 N 870 0.04 10 5 pyroxeni te 750G503E N L B B B B B oeridoti te TO 750G503E N N N 6500 0.02 25 10 peridoti te I 75KB007A N 150 N 45 0.04 10 35 unclass. dike £ 75K6023B N 100 0.15 35 0.02 30 H 15 si Its tone 00 75KB038B N 50 N L 0.1ft L 20 granodiorite £ 75KB046A N 100 N 30 0.02 5 25 horn feIs 75KB0468 N 150 N 45 L 10 75 hornfelS £ 76AF031B N 100 N 20 0.0? 10 85 met agraywacke 76AF046B N 150 N 20 0.02 10 100 schist 76AF050A 200 100 N 70 - 0.02 10 140 schist 0 76AF056A N 30 N 30 0.04 L 10 qabbro 76AF0568 N 30 N 25 0.02 L 10 gabbro 0 76AF0648 N 150 N 1RO 0.02 5 40 andesi te 76AF064C N 150 N 210 0.02 5 45 andes i te 76AF069C N 10 N 70 0.02 5 25 hornblendi te 0 76AF0690 N 10 N 190 0.02 5 25 hornblendi te 76AF069E N 20 N 320 0.04 5 10 nneiss 0 76AF069F N 20 N 300 0.02 5 10 Qneiss 76AF078A N 20 N L 0.02 L 10 alaskite 76AF078B N 15 N L 0.02 L 10 alaskite Q 76AF079A N 30 N 5 0.02 5 35 granodior i te 76AF079B N 70 N 5 0.02 5 35 granodi ori te 0 76AF082A N 70 N L 0.02 10 55 qranodi orite 76AF082B N 150 N L 0.0? 5 45 qranodiori te 76AF088B N 10 N 1500 0.02 10 30 qabbro <§ 76BJ025A N 150 N 20 0.02 15 05 qraywac ke 769J025B N 150 N ?0 6.02 15 95 qraywacke ^ 768J027B N 100 N 35 0.02 30 R5 schist Table B- 8. --Anornalous bedrock qeochpmical samples collected by the Geological Survey.-continued Sample Latitude Longitude Aq (ppm) As (ppm) Au (ppm) R (ppm) Ba (ppm) Be (ppm) Pi (-ppm) Ca (X) 76BJ030B 58 16 27N 136 41 18W N N 15 1000 N 2.00 Hi 768J030C 58 16 27N 136 41 18U N N 15 700 M 3.00 768J038A 58 17 34N 136 40 SOW N N N 150 N 1.50 763jn38B 58 17 34N 136 40 SOW N N N 700 N 1.50 0 76BJ057A 58 25 54N 136 51 43W N N 1S L N 10.00 76BJ057B 58 25 54N 136 51 43U N N 15 L N 10.00 0 76BJ062B 58 13 47N 136 38 52W N N 100 1500 N 3.00 76BJ069A 58 21 29N 136 43 30W N N I5n 1500 N 5.00 76BJ069B 58 21 29N 136 43 30W N N 100 1500 N 5.00 0 76BJ077A 58 27 17N 136 54 13W N N 10 150 N m.oo 76BJC77B 58 27 17N 136 54 13W N N 10 1 50 N 10.00 0 76BJOP3A 58 27 53N 136 53 41U N N in 50 N 7.00 76BJ083B 58 27 53N 136 53 41W N N 10 50 N 7.00 0 ' 76BJ083C 58 27 53N 136 53 41U N M 10 50 N 7.00 76BJ099A 58 40 40N 137 32 27W N N so 150 N 7.00 tx) 76BJ099B 58 40 40N 137 32 27W N N so 100 N 5,00 0 M 76BJ142C 58 24 37N 137 00 56W N M 20 L N 7.00 »£> 76BJ154A 58 44 14N 137 37 25W N N 70 ion N 5.00 & 769J154B 58 44 14N 137 37 25W N N so 100 N 5.00 0 76BJ169B 58 52 13N 137 47 13W N N 20 50 N 3.00 76BJ173A 58 44 28N 137 38 15W N N 50 100 N 3.00 0 76BJ174A 58 33 27N 137 13 49W N N m 20 N 5.00 76BJ174B 58 33 27N 137 13 49W N M 15 20 N 5.00 76CN002A 58 20 29N 136 43 11W N N in 700 N 3.00 0 76CN002B 58 20 29N 136 43 1 1W N N m 1000 N 5.00 76CN003B 58 21 59N 136 42 08W N N 30 L N 7.00 0 76CN005C 58 24 49N 136 45 08U N N 15 1500 N 3.00 76CN0050 58 24 49N 136 45 08U N N 15 1500 N 3.00 76CN0068 58 23 08N 136 48 22U N M 10 2000 N 5.00 0 76CN011B 58 27 OON 136 52 47W N N 20 2000 N 5.00 76CNm3B 58 26 37N 136 40 09W N N inn 2000 N 5.00 0 76CN014 A 58 26 41N 136 48 03W N N i5n 2nn N 7.00 76CN014B 58 26 41N 136 48 Q3W N N 100 2on N 7.00 76CN014C 58 26 41N 136 48 03U N N 50 2no N 7.00 0 76CN0140 58 26 41N 136 48 03U N N 50 3no N 7.00 76CNOUE 58 26 41N 136 48 03W N N so 2no N 7.00 tf 76CN015A 58 27 23N 136 47 46W N N 50 300 N 7.00 76CNP15B 58 27 23N 136 47 46U N N SO 200 N 7. 00 76CNC16A 58 28 42N 136 50 44U M N ?0 1500 N 7.00 0 76CN0168 58 28 42N 136 50 44W N N 30 2000 N 5.00 76CN017A 58 31 04N 136 50 38W N N 30 2000 N 7.00 Ufr 76CN019B 58 15 SAN 136 41 22W 0.5 N 20 1500 N 3.00 * in Table B-8. Anomalous bedrock geochemlcal samples collected by the Geological Survey.-continued Sample Cd (ppm) Co (ppm) Cr (ppm) Cu (opm) Fe La (opm) Mg (X) Mn (pom) Mo (com) Nb (ppin) 76BJ030B N 15 100 70 2.00 30 2.00 1500 N N 76BJ030C N 15 70 70 2.00 70 1.50 1500 N L 76BJ038A N L L L 0.70 L 0.05 700 5 N 76BJ038B N L L L 0.70 L 0.05 500 5 N 76BJ057A N 50 ?00 15 7.00 L 5.00 2000 N N 76BJ057B N 50 200 15 5.00 L 5.00 2000 N N 76BJ062B N 15 150 50 5.00 20 2.00 2000 L L 76BJ069A N 15 100 20 2.00 70 1.50 1000 N L 76BJ069B N 15 100 20 2.00 70 1.50 1500 N N 76BJ077A N 30 100 50 3.00 20 3.00 2000 N N 768J077B N 20 150 50 3.00 ?0 3.00 1500 N N 76BJ083A N 50 700 50 5.00 N 7.00 1500 5 N 76BJOK3B N 50 700 50 5.00 N 7.00 1500 N N 76BJ083C N 50 700 100 5.00 N 7.00 1500 N N 76BJ099A N 70 500 10 7.00 N 5.00 2000 N N 76BJ099B N 50 300 1 5 5.00 L 5.00 2000 N N 7 76BJU2C N 50 200 5.00 L 5.00 2000 N N M Ul 76BJ154A N 30 10 150 7.00 L 2.00 2000 N N O 76BJ154B N 30 10 200 7.00 L 3.00 2000 N N 76BJ169B N 15 L 70 5.00 20 1.50 2000 N N 76BJ173A N 50 200 70 7.00 L 2.00 1500 N N 76BJ174A N 50 300 50 7.00 L 2.00 1500 N N 76BJ174B N 50 300 50 7.00 N 2.00 1500 N N 76CN002A N 5 10 70 1 .50 50 1.00 1500 N N 76CN002B N 5 15 10 1.50 mo 1.00 1500 N N 76CNOP3B N 30 100 150 5. On 20 5.00 2000 N N 76CN005C N 10 70 20 2.00 70 2.00 1500 N N 76CN0050 N 15 100 50 2.nn 70 2.00 1500 N N 76CN006B N 15 100 70 2.00 70 2.00 1500 N N 76CN011B N 20 300 15 3.00 20 3.00 >5000 N N 76CN013B N 7 150 100 2. no 50 2.00 2000 N N 76CNOUA N 50 1000 150 5.00 L 5.00 2000 N N 76CNOUB N 30 700 50 3.00 L 5.00 2000 N N 76CNOUC N 30 500 10 2.00 L 5.00 2000 N N 76CNOUD N 10 300 70 2.PO 20 3.00 1500 N N 76CNOUE N 20 300 150 3. on ?0 5.00 2000 N N 76CN015A N 30 300 50 3. on 20 5.00 1500 N N 76CN015B N 30 ?00 20 3.00 L 5.00 1500 N N 76CN016A N 7 150 70 2.00 50 2.00 1500 N N 76CN016B N 10 ?00 100 ?.oo 30 3.00 2000 N N 76CN017A N 15 150 50 2. on 50 3.00 ?oon N N 76CN019B N 7 150 70 ?.on 50 1 .50 1500 N N Table B-Q.--AnomaIous bedrock geochemical samples collected by the Geological Survey.-continued Sample Ni (pom) Pb (ppm) Sh (ppn) Sc (ppm) Sn (ppm) Sr (opn) Ti (X) V (ppin) W (ppn) Y (pp*> 76BJ030B 30 50 N 15 N 3 no 0.700 150 N 15 76BJ030C 20 50 N 15 N 700 1.000 150 N 20 76BJ038A 5 70 N 7 N N 0.010 L N 30 76PJ0383 5 70 N 7 N 100 0.002 L N 30 76BJ057A 150 N N SO N ?oo 1.000 150 N 30 76BJ057B 150 N N 50 N 200 1.000 200 N 30 76PJ062B 30 50 N 20 N 500 1.000 200 N 20 76BJ069A 30 50 N 20 N 700 1.000 150 N 30 76BJ0698 30 50 N 20 N 700 1.000 150 N 30 76BJ077A 100 L N 30 N 500 1.000 200 N 30 76BJ077B 100 L N 30 N 500 0.700 150 N 30 76BJ083A 150 N N 50 N 500 0.150 200 N 10 76BJOR3B 150 N N SO M 300 0.150 150 N 10 76BJ083C 150 N N SO N 300 0.150 200 N 10 76BJ099A 100 N N 70 N 100 0.500 200 N 30 ro 76BJ099B 70 N N 70 N 100 0.300 200 N 30 76BJU2C 70 N N 50 N 100 0.500 200 N 30 76BJ15AA 7 15 N 30 N 500 0.700 200 N 30 76BJ154B 7 N N 30 N soo 0.700 300 N 20 41 76BJ169B 7 N N 30 N 300 1.000 150 N 30 763J173A 70 N M 50 N 200 0.500 300 N 20 76BJ17AA 100 N N 50 N 150 0.500 200 N 20 76BJ174B 100 N N 50 N ISO 1 .000 200 N 30 76CN002A 5 50 N 10 N 200 0.500 30 N 30 76CN002B 5 50 N 10 N 300 0.500 30 N 30 76CN003B 30 N N 30 N L 0.300 1SO N 20 76CN005C 20 SO N 15 N soo 1.000 100 N 20 76CNC050 30 50 N 15 N 500 1.000 150 N 20 76CN006B 20 50 N 15 N 500 1.000 150 N 20 76CN'ni18 50 30 N 15 N 300 1.000 150 N 30 76CN013B 20 50 N 15 N 300 1.000 150 N 30 76CN014 A 200 L N 15 N 300 0.200 200 N 10 76CN01 AB 50 L N 20 N 300 0.200 200 N 10 76CNOUC 30 L N 20 N 200 0.150 200 N L * 76CNOHD 10 L N 15 N ?oo 1.000 200 N 15 76CNOUE 30 10 N 15 N 300 >1.000 200 N 15 * 76CN015A 70 L N 20 N 200 0.150 200 N L 76CN015B 50 L N 20 N 200 0.150 200 N 10 76CN016A 10 50 N 15 N 300 1.000 ISO N 30 0 76CN016B 20 50 M 1 5 N 300 1.000 150 N 30 76CN017A 30 70 N 15 N 300 1.000 1SO N 30 * 76CN019B 10 SO N 15 N 500 1 .000 150 N 20 Table B- 8. --Anomalous bedrock geochemical samples collected by the Gealoqical Survey.-continued Sample In (ppm) Zr (DPIA) (opm) Cu (ppm) Hg 1 (pom) Pb (opm) Zn (ppm) L i tholoqy 76BJ030B L 70 N 75 0.02 15 1AO schist 76BJ030C N 100 N A5 0.02 10 85 qr aywack e 76BJ038A N 100 N N 0.02 L 20 qrani te 76BJ038B N 70 N N O.OA N AO qr anodior i te 763J057A N 100 N 10 0.02 L 10 qreens tone 768J057B N 100 N 15 O.OA L 15 qr eens tone 76BJOA2B N 100 N 35 n.OA 25 110 schist 76PJ069A N 150 N 15 O.OA 10 80 grayuac he 763JOA98 N 150 N 15 O.OA 10 80 qraywacke 768JC77A N 100 N 40 O.OA L 10 dior i t e 76BJ077B N 100 N 40 0.02 L 10 dfori te 76BJ083A N L N 55 L 5 20 qabbro 766J083B N L N AO 0.0? 10 20 qabbro 76BJ083C N L N 100 L 10 20 qabbro 76BJ099A N 30 N L 0.0? L 15 di ori te 76BJ099B N 30 O.?0 10 0.02 L 15 diori te I 763J1A2C N 30 N 310 O.OA N L schist ui 76BJ15AA N 10 N 130 L 10 35 di ori te to 76PJ15AB N 10 N 160 0.02 10 AO diori te 76BJ169B N 100 N 55 L 10 150 qnei ss 763J173A N 30 N 75 0.0? 10 ?5 qnei ss 76BJ17AA N 50 N 30 0.0? L 30 schist 76BJ17AB N 70 N ?0 O.OA L 25 schist 76CN002A N 150 N 5 0.02 10 55 qranodior i t 76CN003B N N 180 O.OA L L schist 76CN005C N 150 N 1 5 0.0? 10 65 qnei ss 76CN0050 N 150 N 30 O.OA 10 75 qnei ss 76CNP06B L 100 N AO OiO? 10 1?0 schist 76CN0118 N 100 N 10 O.OA 10 35 schist 76CNni3B N 100 N 80 O.OA 10 85 schist 76CN01AA N 10 N 1AO L 10 A5 hornf el s 76CN01AB N 30 N A5 0.0? 10 A5 hornf el s 76CNOUC N 10 N 10 0.02 5 AO qneiss 76CN01AO N 100 N 95 O.OA 5 AO qnei ss 76CN01AE 100 1 AO 0.0? 5 AO qnei ss 76CN015A N 30 0.0? 10 25 diori te 76CN015B N 20 o.o? 5 20 di ori te 76CNP16A 100 30 O.OA 10 60 qnei ss 76CN016B 100 50 O.OA 10 90 one i ss 76CN017A 100 30 O.OA 10 95 qneiss 76CKT19I3 100 55 O.OA 10 70 schist Table 0- 8. --Anomalous bedrock geochemical samples collected by the Geological Survey.-continued Sample Lati tude Longitude Ag (ppm) As (pom) Au (pom) 9 (ppm) Ra (ppm) Be (ppm) fH (ppm) Ca (X) 76CN023A 58 18 AAN 136 51 OOW N N N 30 100 N N 7.00 76CN025C 58 19 05N 136 52 33W M N N 7 L N N 10.00 76CN026A 58 20 50N 136 50 A7W N N N 30 1000 1 M 5.00 76CN026B 58 20 50N 136 50 A7W N N N 15 1000 1 N 5. on 76CN032B 58 17 13N 136 39 AOW N N N 10 1500 2 N 3.00 76CN036B 58 18 29N 136 39 SOW N N N L 500 2 N 3.00 76CN036C 58 18 29N 136 39 50W N N N L 700 2 N 3.00 76CNOA5A 58 27 03N 136 55 13W N N N L 1000 1 N 1.00 76CNOA5B 58 27 03N 136 55 13W N N N L 1000 1 N 1.00 76CNOA5C 58 27 03N 136 55 13W N N N 1000 1 N 1.00 76CNOA7B 58 30 A1N 136 50 51W N M 50 1 50 L N 10.00 * 76CNOA8B 58 31 16N 136 50 32W N N m 1500 1 N 5.00 76CN052A 58 31 10N 136 53 A5W N N 30 L M N 10.00 76CNC52B 58 31 10N 136 53 A5W N N 30 20 N N 10.00 76CN059A 58 36 25N 136 26 26W 0.5 N 15 ?00 L N 1.00 td 76CN059Q 58 36 25N 137 26 26W L N so 300 L N 1.00 ' 76CN059C 58 36 25N 137 26 26W 3.0 M 50 300 L N 0.15 en 76CN070B 58 33 26N 137 20 11W N M 30 70 N N 3.00 w 76CN07AA 58 33 57N 137 20 26W N N 50 L N N 5.00 76CN07AB 58 33 57N 137 20 26W N N 50 20 N N 7.00 76CN07AC 58 33 57N 137 20 26W N N 50 L N N io.no 76CN079A 58 38 12N 137 3A 27W N N 100 100 N N 3.00 76CN0799 58 38 12N 137 3A 27W N N 150 100 N N 3.00 76CN088C 53 38 3AN 137 30 35W N N 30 L N N 7.00 76CN101C 58 3A OAN 137 18 31W N N 15 L N N 10.00 76CN1010 58 3A OAN 137 18 31W N N 15 L N N 10.00 76CN106C 58 A2 DON 137 27 10W L M 15 150 L N 3.00 76CN107A 58 A3 03N 137 29 01W N M m L N N 7.00 76CN1078 58 A3 03N 137 29 01W N 10 L N N 7.00 76CN109B 58 A3 52N 137 29 32W N L L N N 7.00 76CN109C 58 A3 52N 137 29 32W N 10 L N 3^00 76CN109D 58 A3 52N 137 29 32W N 10 L N 7.00 76CN111 A 53 23 57N 137 06 A6W N 50 700 N 2.00 76CN116A 58 39 15N 137 29 AOW N 150 1000 N 1.50 76CN116C 58 39 15N 137 29 AOW 0.5 200 2000 N 1.50 76CN117A 58 39 21 N 137 29 3AW N 10 100 N 7.00 76CN117B 58 39 21N 137 29 3AW N 10 70 N 7.00 76CN121 A 53 AA 37N 137 39 21W N ?on 70 N 7.00 m 76CN121B 53 AA 37 N 137 39 21W N 5P 1 50 N 5.00 76CN123A 58 AA 33N 137 AO 37W N ?0 100 N 5.00 76CN1230 58 AA 33N 137 AO 37W L ?n L N 7.00 Table P-8.--Anoma I ous bedrock g«»oc h«"n ica ( samples collected by the Geological Survey.-corvt inued Samplc Cd (ppm) Co (ppm) C r ( ppm) Cu (nom) Fe La (pom) Mrv (ppm) MO (pom) Nb (ooffl) 76CN023A N 50 1000 100 5.00 20 5.00 1500 N N 76CN025C N 50 200 1 5P 15.00 N 5.00 5000 N N 76CK026A N 15 150 70 5.00 50 2.00 1500 N N 76CN026B N 10 100 20 3.00 50 2.00 2000 N N 76CN0328 N 5 30 1 5 1.50 70 1 .50 1500 N N 76CN036B N L L 5 n.50 50 0.03 700 N N 76CN036C N L L L 0.50 30 0.03 700 N N 76CN045A N N L L 0.70 30 0.15 1500 N N 76CNOA58 N N L L 0.50 30 0.15 1500 N N 76CN045C N N L 20 0.50 30 0.10 1500 N N 76CN047B N 30 500 50 2.00 20 5.00 2000 N N t 76CN0488 N 5 700 15 1.50 70 1.50 1500 N N 76CN052A N 30 500 150 5.00 N 5.00 2000 N N 76CN052B N 70 700 200 7.00 N 5.00 2000 N N 76CN059A N 20 100 100 2.00 30 2.00 1500 N N w 76CN0598 N 20 200 70 ?.oo 30 2.00 1500 N N 76CN059C N 7 50 70 2.00 30 1.00 700 15 N tn 76CN070B N 30 300 70 7.00 L 3.00 2000 5 N 76CN074A N 70 700 50 7.00 N 5.00 1500 N N 76CN07A8 N 70 100 ?no 7.00 N 3.00 1000 N N 76CN074C N 50 20 300 7.00 N 3.00 1500 N N 76CN079A N 50 500 100 7.00 L 3.00 2000 N N 76CN079B N 200 300 100 7.00 L 2.00 2000 N N 76CN088C N 20 100 L 2.00 20 2.00 1000 N N 76CN101C N 70 1500 L 5.00 N 5.00 1500 N N 76CN101D N 70 1500 L 5.00 N 7.00 1500 L N 76CN106C N 20 10 200 5.00 L 1.50 3000 L N 76CN107A N 50 700 200 3.00 L 5.00 1500 L N 76CN107B N 70 1 500 50 5.00 L 7.00 HOO N N 76CN1098 N 30 700 L 2.00 L 5.00 1000 5 N 76CN109C N 70 3000 50 5.00 N >10.00 1500 L N 76CN1090 N 70 2000 30 7.00 N >10.00 1500 5 N 76CN111A N 15 150 30 3.00 50 1.50 1000 15 N 76CN116A N 50 150 150 3.00 30 ?.oo >5000 L N 76CN1168 N 30 200 70 5.00 ?0 2.00 >5000 5 N 76CN116C N 20 150 200 5.00 100 1 .50 5000 20 N 76CN117A N 50 700 50 3.00 20 2.00 1500 L N 76CN117B N 50 700 70 3.00 20 3.00 1500 5 N 76CN121A N 30 30 100 5.00 L 2.00 2000 L N O 76CN1218 N 50 70 1 50 7.00 N 2.00 3000 L N 76CN123A N 50 300 ?no 7.00 L 2.00 1500 N N 76CN123B N 70 500 150 7.00 N 2.00 1500 L N Table B-8 .--Anoma I ous bedrock qeoche 76CN023A 100 N 30 N 700 > 1.000 150 N 20 * 76CN025C 70 N SO N N >1 .000 700 N 15 76CNP26A 20 50 20 N 500 1.000 150 N 20 76CN0266 30 50 15 N 500 1 .000 150 N 20 ft 76CN0328 7 50 15 N 300 0.300 70 N 20 76CNP36B 5 100 5 N 100 0.002 10 N 20 9 76CN036C 5 70 5 N 100 L L N 15 76CNOA5A 5 50 5 N L 0.003 L N 20 76CNPA5B 5 50 5 N L 0.003 L N 10 ft 76CNOA5C 5 50 N L 0.002 10 N 10 76CNOA7B 70 20 30 1 50 0.500 200 N 20 * 76CN048B 10 30 10 700 0.500 100 N 20 76CN052A 70 N 50 100 0.500 200 N 20 76CN052B 100 N 50 100 0.700 300 N 30 76CN059A 30 L 20 100 >1 .000 150 N 30 76CNP59B 50 L 20 300 > 1.000 150 N 20 I 76CN059C 10 L 20 L >1 .000 150 N 20 on 76CN070B 50 N 70 200 > 1.000 200 N 20 On 76CN074A 150 N 30 150 0.500 150 L L 76CN074B 30 N 30 500 0.700 500 10 76CN074C 30 N 50 500 1.000 700 10 ft 76CN079A 100 N 30 700 1.000 200 20 76CN079B 100 N 50 300 >1.000 200 30 76CN088C 50 30 200 0.500 150 20 ft 76CN101 C 300 50 N 0.100 100 10 76CN1010 300 N 50 N 0.150 100 10 ft 76CN106C 7 10 50 500 >1.000 300 70 76CN107A 200 N 50 700 0.500 150 15 76CN107B 300 N 50 500 0.700 ?00 ?0 ft 76CN1093 200 N 20 L 0.150 100 10 76CN109C 2000 N 1 5 N 0.100 50 10 ft 76CN1090 2000 N 20 N 0.500 70 10 76CN111A 70 10 ?0 500 1.000 150 30 76CN116A 100 50 30 200 1.000 200 30 ft 76CN116B 100 10 30 7.00 >1 .000 ?00 30 76CN116C 150 20 20 100 1.000 *00 50 49 76CN117A 70 N 50 700 1 .000 300 ?0 76CN1'178 50 N 50 700 1.000 ?00 20 76CN121 A 30 N 50 200 0.500 300 15 ft 76CN121B 30 N 70 500 0.700 500 ?0 76CN123A 100 50 200 1 .000 200 30 y> 76CN123B 150 50 200 > 1.000 200 30 Table B-8. Anomalous bedrock geochemical samples collected by the Geoloqical Survey.-continued Sample Zn (ppm) 2r (ppm) Au ' (ppm) Cu ' (ppm) Hq' (ppm) Ph ' 76CNP47B N 50 N 35 0.04 10 25 diori te ^ 76CN0488 N 100 N 15 0.02 10 55 gneiss 76CN052A N 20 N 160 0.04 5 L qnei ss 76CN052B N 30 N ?1 0 0.02 5 L qneiss <9 76CN059A N 100 N 85 0.14 10 55 qr aywack e ro 76CN059B N 100 N 50 0.16 10 45 qravuacke 9 ' 76CNP59C N 100 N 40 0.30 5 15 qraywacke 76CN070B N 20 a*Ul N 65 0.02 10 75 diori te 76CN074A N N N 45 0.02 15 40 qreenschi st 76CN0748 N N N 180 0.02 10 55 qr eenschi s t 76CN074C N N N 270 0.0? 10 50 qreenschist 4£ 76CN079A N 50 N 95 L 15 80 qraywacke 76CN0798 N 30 N 75 0.06 15 80 qraywacke 76CNC8F C N 100 N L 0.10 10 15 di ori te 76CN101C N N N L N L 10 qneiss 76CN101D N N N N N N 5 qnei ss O 76CN106C N 150 N 180 0.04 5 80 schist 76CM107A N 70 N 3PO 0.04 N 5 gneiss 76CN1078 N 50 N 55 0.04 N 5 qnei ss <» 76CN109B N N N 5 0.02 L L schist 76CN109C N N N 35 P.02 5 10 qne i ss * 76CN1090 N 10 N 40 0.04 L 5 aneiss 76CN111 A N 150 N 1 5 0.02 10 80 sandstone 76CN116A N 100 N 85 0.02 30 1 20 phyllite «* 76CN116B N 150 N 50 0.04 15 1?0 phylIite 76CN1 16C 300 150 N 150 L 15 730 phyllite 4* 7 6 C N 1 1 7 A N 70 N 40 0.02 10 45 chert 76CN117B N 70 N 45 0.02 15 40 ohyllite 76CN121 A N 15 N 65 0.04 10 60 diori te * 76CN121B N L N 100 0.04 10 65 diori te 76CN123A N 70 N 220 0.0? 5 60 qreenstone & 76CN123B N 100 N 130 0.02 5 55 greenstone Table B-8. Anomalous bedrock geochewical samples collected by the Geological Survey.-continued Sample Lati tude Longitude Aq (pom) As (pom) Au (pom) B (DPffl) Ba (ppm) Be 76CN124B 58 44 04N 137 40 32W N N N m L N N 20.00 £ 76CN125A 58 43 33N 137 40 17W N N N 50 20 N N 7.00 76CN132A 58 54 06N 137 44 44W N N N 20 L N N 10.00 76CN137B 58 48 04 N 137 43 09W N N N 50 700 L N 2.00 76CN138A 58 48 02N 137 43 27W N N N 50 50 N N 7.00 76CN138B 58 48 02N 137 43 27W N N N 50 20 N N 7.00 0 76CN141A 58 47 53N 137 44 27U N N N 50 50 N N 7.00 76CN141B 58 47 53N 137 44 27W N N N 50 70 N N 7.00 76CN141C 58 47 53N 137 44 27W N N N 30 150 N N 15.00 e 76CN1410 58 47 53N 137 44 27W N N N 30 70 N N 15.00 76CN141E 58 47 53N 137 44 27U N N N 50 100 N N 7 R 00 £ 76CN141F 58 47 53N 137 44 27W N N N 50 100 N N 7.00 76CN142B 58 43 15N 137 42 22U N N N 50 300 L N 5.00 76CN1520 58 30 41N 137 12 10W N N N 10 N N N 10.00 76CN153A 58 42 19N 137 35 12W N N N 150 20 N N 10.00 to 1 76CN153B 58 42 19N 137 35 12U N N N 100 100 N N ioloo ~ 01 76CN154E 58 43 31N 137 39 37W N N N 20 1000 N N 7.00 76CN154F 59 43 31N 137 39 37W N N N 20 700 N N 7.00 760B116B 58 16 22N 136 43 23W N H N 10 1 50 N N 3.00 760B116C 58 16 22N 136 43 23W N N N 10 150 N N 5.00 760B1160 58 16 22N 136 43 23U 0. 5 N 10 700 1 N 2.00 41 760B119A 58 16 42N 136 42 19W N N 20 1000 1 N 3.00 760B119C 58 16 42N 136 42 19W 0. 7 N L 500 L N 1.00 760B120A 58 15 29N 136 37 52W N N ?0 700 L N 1.50 9 760B121C 58 16 07N 136 37 32U N N 200 1000 1 N 1.00 76DB129A 58 24 07N 136 48 43U N N N 700 2 N 2.00 9 760B129B 58 24 07N 136 48 43W N N N 1000 2 N 3.00 760B133G 58 23 53N 136 54 40W N N 10 L N N 5.00 760B1370 58 32 16N 136 54 20W N N 10 70 N N 5.00 760B140B 58 31 28N 136 51 26U N N 10 200 L N 7.00 760B150C 58 32 15N 136 55 40U N N 10 70 N N 5.00 41 760B157E 58 37 34N 137 29 24W 2. 0 N 70 700 1 N 1.00 760B159C 58 37 SON 137 28 13W 1. 0 N 30 700 L N L 76DB166A 58 43 23N 137 35 35W N N 50 500 L N 7.00 76DB166B 58 43 23N 137 35 35U N N 30 200 L N 7.00 76DB169A 58 42 ION 137 34 16U N N 50 70 N N 3.00 * 760B172A 58 41 16N 137 35 59W N N 30 20 N N 7.00 760B172B 58 41 16N 137 35 59W N N 30 20 N N 7.00 760B191C 58 36 42N 137 20 19w N N 20 L N N 7.00 * 760B192A 58 36 42N 137 20 48W N N 30 L N N 7.00 760B192C 58 36 42N 137 20 48U N M 30 L N N 7.00 m 760B1920 58 36 42N 137 20 48U N N 30 L N N 7.00 Table P-8. Anomalous bedrock geochemical samples collected by the Geological Survey.-cont inued Sampl e Cd (ppm) Co (ppm) Cr (ppm) Cu (ppm) Fe La (ppm) (X) M n (opm) Mo (pom) Nb (ppm) 76CN12AB N 20 100 70 00 20 1.50 2000 in N 76CN125A N 70 150 70 00 N 3. on ?nno L N 76CN132A N 20 300 30 no L 3.00 1500 N N 76CN137B N 10 30 15 50 30 1.50 1500 N N 76CN138A N 30 200 50 on 20 5.00 isno N N 76CN138B N 50 300 50 3.00 20 5.00 isno N N * 76CN1A1A N 30 150 20 00 20 3.00 2000 N N 76CNU1B N 30 200 50 00 ?0 5.00 1SOO N N 76CN1A1C N 15 100 300 on 20 1.50 3000 N N 76CN1A10 N 15 100 200 so 20 1.50 ?noo 5 N 76CN1A1E N 50 300 70 5.00 L 5.00 1500 N N 76CN1A1F N 30 300 70 5.00 20 5. 00 i5on N N 76CNU2B N 20 50 70 5.00 ?0 2.00 ?non N N 76CN1520 N 30 1500 70 ?.on L 5.00 1500 N N 76CN153A N 30 700 50 ?.on L 5. on 1500 N N td 76CN153B 30 1000 70 .no N 5.00 1500 N N 76CN15AE 50 70 300 ,nn L 2.00 3000 N N Ul 76CN15AF 30 500 00 50 ,00 N 3.00 3000 N N 760B116B 30 1000 L ,00 N 3.00 1500 N N 760B116C 50 1000 L .00 N 3.00 1500 N N 760B116D 15 70 150 2.00 20 1 .50 moo N N 76DB119A 20 150 70 5.00 20 ?.oo 1500 N N 760B119C 70 30 200 7.on 20 n.7n toon N N 760B120A ?0 300 L 3.00 ?0 1.50 7no N N 0 760B121C 30 100 70 3.00 30 1 .50 1000 N N 760B129A L 10 L 0.70 L 0.30 500 N N * 760B129B 5 10 L 00 L 0.50 500 5 N 760B133G 70 700 300 00 N 5. on 1500 N N 760B1370 50 300 70 on L 5.00 1500 N N 760B1ACB 30 300 30 nn L 5.00 ?ono N N 760B15CC 50 500 70 oo L 5.00 1500 L N 760B157E 15 100 50 on 30 1.50 7on L N 760P159C 7 100 100 oo 30 1.00 2noo L N 760B166A 30 300 100 oo 70 3.00 1500 N N 760B166B 30 300 L 3.no L 3.00 2000 N N 760P169A 30 50 70 nn 20 2.00 ?nnn N N 760B172A 50 70 200 no L 3.00 *noo N N 760B172B 20 50 150 on 20 3.00 sonn N N 760B191C 30 100 300 nn 20 3. on *ono N N 760P192A 50 200 150 7.no ?0 3. on 3nnn N N 760P192C 30 150 500 ?.no 20 3.00 3nnn N 760B1920 30 150 300 7.no ?0 3.nn 3nno N w Table B- 8.--Anomalous bedrock qeochemical samples collected by the Geological Survey.-continued Sample Ni (ppm) Pb (oom) Sb (ppm) Sc (pom) Sn (oom) Sr (com) Ti (X) V (ppm) W (pom) Y (pom) 76CN124B 30 N N N 100 0.100 100 N 10 fy 76CN125A 100 N N 70 N ISO 1.000 500 N 30 76CN132A 30 N N 30 N 1 on 0.200 150 N 20 76CN137B 10 L N 15 N soo 0.500 70 N 30 * 76CN138A 70 N N 30 N 300 0.300 100 N 15 76CN138B 100 N N 30 M ?no 0. 300 150 N 15 0 76CN141 A 50 N N 30 N 300 0.300 150 N 20 76CNU1B 70 N N 30 N 200 0.300 200 N 20 76CNU1C 30 N N 30 N 200 0.300 200 N 30 76CNU1 D 20 N N 30 N 1 50 0.500 200 N 30 76CNU1E 70 N N 50 N 200 0.500 200 N 30 76CNU1F 70 N N 50 N ?00 0.500 200 N 30 76CNU2B 10 10 N 30 N 500 0.700 150 N 50 76CN1520 150 N N 50 N 100 0.100 100 N 10 76CN153A 70 N N 30 N 100 0.500 150 N 20 dd 76CN153B 100 N N 30 N 200 0.700 150 N 30 0 *! 76CN154E 50 N N 50 N 1 50 1.000 300 N 50 en <£> 76CN154F 30 N N 50 N 100 1.000 300 N 50 760B116B 150 L N 30 N 1 00 0.200 150 N 20 760B116C 150 L N 50 N 150 0.300 150 N 30 76DB116D 20 20 , N 15 N 500 1.000 100 N 20 41 76DB119A 50 50 N 1 5 N 700 1.000 150 N 30 76DB119C 150 L N 7 N 150 0.150 50 N 15 760B120A 50 10 N 15 200 1.000 100 N 20 760B121C 70 20 N 20 150 0.700 100 N 30 760B129A 5 50 N 5 300 0.100 10 N L H 760B129B 5 50 N 5 500 0.150 15 N L 76DB133G 100 N N 70 N 1.000 150 N 20 76PB137D 150 N N 50 100 1.000 150 N 30 * 760BUOB 50 L N 50 100 0.300 200 N 20 760B150C 70 N N 50 200 0.500 700 N 15 « 760B157E 30 10 N 15 200 0.700 150 N 20 76DB159C 30 10 N 30 100 1.000 100 N ?0 76DB166A 70 N N 50 300 0.300 200 N 20 * 76DP1668 50 N N 50 200 0.500 200 N 30 760P169A 20 N N 50 100 >1 .000 300 N 70 w 760B172A 70 N N 50 150 0.700 ?00 N 30 760B172B 20 N N 50 200 0.500 300 N 30 76DB191 C 50 N N 30 100 0.500 300 N 30 * 76DB192A 70 N N 50 100 1.000 300 N 70 76DB192C 30 N N 30 N 1 .000 300 N 30 & 760B1920 50 N N 50 L >1 .000 300 N 50 Table P-8.--Anoroa I ous bedrock qeochemical samples collected by the Geological Survey.-cont Sampl e Zn (ppm) Z r (ppm) Au (ppm) Cu (npm) Hq' (pom) Pb (ppm) Zn ' 76CN12A8 N 10 0.10 ?n H 15 chert 76CM125A N 50 50 0.10 10 80 qreenstone 76CN132A N 20 40 n.?? N L qne i ss 76CN137B N 1 50 10 0.10 5 30 di orite 76CN138A N 30 50 n.i? 10 AO qreenstone 76CN1388 N 30 40 0.08 10 50 greenstone 76CN1A1 A N 30 15 0.1A 15 H 50 qreenstone 76CN1A1B N 30 AO 0.28 10 A5 qreenstone 76CN1A1 C N 30 330 1.50 15 H AO rhyoli te 76CN1A1D N 50 220 1.20 15 H 30 rhvoU te 76CN1A1E N 70 55 0.2A 15 50 phyllite 76CN1A1 F N 50 65 0.?A 15 60 phyllite 76CN1A2B N 100 15 0.1A 5 35 areenstone 76CN1520 N N 35 O.OA 10 L qneiss 76CN153A N 30 50 0.02 20 AO qreenstone 76CN1538 N 50 td 55 O.OA 15 A5 qreenstone i 76CN15AE N 100 250 O.OA 10 A5 hornfels H 76CN15AF N 100 O.OA 5 55 hornfels 0 76DB1168 N 20 L 0.02 5 30 qr eenschis t 76DB116C N 30 N 0.1?. 5 20 qreenschist 760B1160 L 150 110 O.OA 10 80 semi schist 760B119A L 150 ?5 D.OA 10 95 semi schist 760B119C N 50 170 0.06 10 35 auartzite 760B120A N 100 5 0.02 10 75 semi schist 760B121C 200 150 60 O.OA 10 150 si ate 760B129A N 70 N 0.12 5 50 qrani te e 760B1 298 N 100 N 1.0A 5 50 qrani te 760B133G N 20 AOO 0.02 L 5 pyroneni te 760B1370 N 50 50 0.02 10 10 rti or i te 760B1AOB N 30 25 O.OA 10 15 qabbro 760B150C N 50 50 H.OA L L di ori te 76DB157E N 100 AO 0.06 15 85 silts tone 760B159C N 100 80 0.06 25 25 brecc ia 760B166A N 30 130 0.0-A 5 20 schist 76DB166B N 20 L 0.02 5 35 schist 760B169A 200 150 55 O.OA 15 180 phylIi te 76DB172A N 30 2AO N 10 50 cataclastite 760B172B N 20 1 AO 0.06 5 AO catacIast i te 76DB191C N 30 ABO 0.0? N 5 schist 760B192A N 70 110 O.OA N 5 schist 760B192C N 70 A50 O.OA N 15 schi st 760B1920 N 70 380 O.OA L 15 schi st Table B-8.--AnomaIous bedrock geochemical samples collected by the Geological Survey.-continued Samp I e Lati tude Longitude Ag (ppm) As (opm) Au (pom) fl (ppm) Ba (ppm) Be (ppm) Bi (ppm) Ca (X) 76DB233A 58 42 48N 137 27 46U 1.0 N N 15 20 N N 5.00 760B237A 58 45 33N 137 27 07W 0.7 N N 15 500 2 N 3.00 760B237B 58 45 33N 137 27 07W L N N 15 300 2 N 3.00 760B265A 58 45 37N 137 39 35W N N N 50 150 N N 3.00 760B2678 58 46 07N 137 40 43W N N 70 150 N N 7.00 760B273A 58 43 22N 137 34 21U N N 10 50 N N 7,00 760B273B 58 43 22N 137 34 21W N N 10 20 N N 5.00 760B276A 58 50 07N 137 37 58W N N 10 50 N N 5.00 760B276B 58 50 07N 137 37 58W N N 10 50 N N 5.00 760B280A 58 42 20N 137 28 52W N M 10 L N N 7,00 76DB280C 58 42 20N 137 28 52U N N L 50 1 N 2.00 76DB282B 58 42 24N 137 30 14U N N 10 20 L N 5.00 76DB285A 58 47 12N 137 30 14U N N 10 20 N N 7.00 760B2858 58 47 12N 137 30 14W N N 10 L N N 7.00 760B285C 58 47 12N 137 30 14W N N 10 L N N 5.00 760B2850 58 47 12N 137 30 14W N N 15 50 L N 5.00 760B286D 58 46 23N 137 29 42W N N so 1000 1 N 1.50 760B286E 58 46 23N 137 29 42U N N 15 200 L N 5.00 760B286F 58 46 23N 137 29 42W N N 15 300 L N 5.00 760B288C 58 45 51N 137 44 01U N N 30 100 L N 3.00 760B2880 58 45 51N 137 44 01U N N 30 300 L N 3.00 760B289A 58 45 48N 137 44 46U M N 30 150 L N 20.00 760B2898 58 45 48N 137 44 46U N M 20 1 50 L N >20.00 760B289C 58 45 48N 137 44 46W N H 15 L 1 N 20.00 760B2890 58 45 48N 137 44 46U N N 15 200 L N ?0.00 76DB292A 58 45 01N 137 44 27W N N 20 20 N N 5.00 7608294A 58 49 03N 137 38 28U N M 10 L N N 7.00 7608?940 58 49 03N 137 38 28U N N 10 L N N 7.00 760B296E 58 39 30N 137 29 13W 0.7 N 20 50 L N 3.00 760B296F 58 39 30N 137 29 13W 0.7 H 30 1 50 L N 3.00 76DG001 A 58 28 35N 136 58 OOU M N 20 20 N M 7.00 760G003A 58 27 35N 136 59 SOW N N 30 L N N 7.00 760G007B 58 37 08N 137 27 25W 1.0 M 70 100 L N 5.00 76DG008B 58 37 12N 137 27 05U L N 100 700 L N 5.00 76DG012A S8 36 08N 137 25 33W N N 100 700 L N 1.00 760G015A 58 31 15N 137 16 13W N N 30 150 L N 7.00 760G016A 58 29 43N 137 12 44U 1.0 N 100 500 L N 1,00 760G032A 58 39 03H 137 21 37W N N 50 1000 L N 3.00 760G0360 58 39 47N 137 26 10W L N SO L N N 7.00 76DG038A 58 42 28N 137 31 28U N N 30 200 L N 5.00 760G044 A 58 40 13N 137 30 53W N M 70 700 L N 3.00 Table D-8.-Ano-i.loui bedrock geochemical samples collected by the Geological Survey, -cont i nued Fe (X) La (pom) (%) (ppm) Mo (pom) Nb Sample N i (ppm) Pb (opro) Sb (opro) Sc (oDffl) Sn (opm) Sr (ppm) n m V loom) W (pom) Y fppm) 760B233A 20 N N 30 N ino 1.000 300 N 30 *> 76DB237A 5 20 N 15 N ?00 0.300 30 N 30 760P237B 5 20 N 15 N 200 0.300 30 30 760R265A 10 N N 20 N 300 0.500 150 15 *% 760B267A 7 N N 30 N 500 1 .000 200 30 7.6DB267B 15 N N 50 N 500 1.000 ?00 30 *b 76DB273A 70 N N 50 N 1 50 0.300 150 15 760P273B 200 N N 100 N 100 1 .000 300 30 76DB276A 70 N N 100 N 150 0.700 300 50 760B280A 200 N N 100 N 100 0.500 200 20 760B280C 5 L N 5 N 100 0.100 30 L 760B282B 200 N N 30 N 100 0.700 150 20 76DP285A 70 N N 30 N 100 1.000 150 20 9 76DB285B 100 N N 50 N 100 >1 .000 200 30 03 76DB285C 70 N N 50 N 100 1.000 200 30 til ^ 76DB2850 70 N N 30 N N 0.700 200 20 cn 760B2P60 50 20 N 20 N 200 1.000 150 20 00 76DB2P6E 100 15 N 50 N 200 0.500 150 20 760B2R6F 100 L N 50 N ?oo 0.500 150 20 76DP2P8C 5 10 N N 200 0.700 150 20 76DB2890 50 L N 20 N 300 0.500 150 20 76DP292A 30 N N 50 N 300 > 1.000 150 30 76DB29AA 150 N N 70 N 1 00 1.000 200 30 760B2940 20 N N 70 100 1.000 300 30 <§ 76PB296E 2000 N N 10 1 50 0.150 50 L 76DB296F 2000 N N 1 5 1 50 0.150 70 L 49 76DG001A 70 N N 50 200 1.000 150 30 76DG003A 50 N N 50 L 0.700 200 30 760G007B 5 N N 10 100 0.150 50 20 ^ 76DG008B 20 10 N 1 5 200 0.700 150 20 76DGC12A 30 30 N 1 5 1 50 0.700 100 20 Hi 760G015A 30 N N 20 300 0.300 150 20 76DG016A 15 20 N 1 5 200 0.700 150 15 76DG032A 30 50 N 15 500 0.500 150 15 ^ 760G0363 30 N N 30 100 0.500 150 30 760GP38A 5 30 N 15 200 0.150 100 15 ^ 76DGOAAA 30 50 N 1 5 200 0.300 100 15 HI Table B-Ss.--Anoma I ous bedrock geochemical samples collected by the Geological Survey.-cont i nued Sample Zn (ppm) Zr (pom) Au (ppm) Cu' (ppm) Hg' (ppm) Pb 1 (ppm) Zn' (ppw) Lithology 76DB233A N 30 N S80 0.0? 5 80 gnei ss 760B237A N 150 0.15 17Q 0.0? 5 75 gneiss 760B?37B N 1SQ 0.10 150 0.04 10 85 onei ss 76DP265A N ?0 N 170 0.0? 10 85 greenstone 76DB267A N 30 N 140 0.02 10 80 di ori te 760B?67B N 30 N ?00 0.02 5 45 diori te 760B?73A N 10 N 5 P.O? L 10 cataclasti te 76DB?73B N ?0 N 30 0.02 5 ?5 cataclastite 76DB276A N 30 N 250 0.04 N 10 gnei ss 760B276B N 30 N 310 0.0? L 10 gnei ss 76t»B?80A N ?0 N 70 0.04 L L gneiss 760B?80C N 150 N 450 L N 15 aplite 76DB?82B N 50 N 65 0.02 N 10 gne iss 760B?85A N 30 N 190 0.0? L 25 greenstone 760B?85B N 50 N 100 0.0? L 30 greenstone td 76DB?85C N 30 N 130 0.0? 10 40 andes i te I 760B?850 N 20 N 160 0.0? 10 45 andesite 76DB?860 N 70 N 130 0.04 20 90 phyllite 760B?86E N 30 N 40 0.04 15 30 greenschist 760B?86F N 30 N 40 0.04 10 25 qreenschist 760B?88C N 70 N 15 0.30 5 20 ohylli te 76DB?880 N 50 N 35 0.18 15 85 phylIi te 760B?89A N 15 N ?5 0.50 ?0 H 60 phyllite 760B?89B N 15 N ?0 0.26 20 H 50 phyllite 76DB289C N 30 N 30 0.18 10 30 greenstone 76DB2890 N 20 N ?0 0.2? 10 35 greenstone 760B?9?A N 100 N 100 0.02 ?0 150 greenstone 760B?94A N 30 N ?20 0.0? L L schist 760B2940 N 70 N ?90 0.02 L 5 qnei ss 76DB?96E N N 0.30 1400 0.0? 15 30 sulfide 76DB296F N N 0.30 1400 N ?0 30 sul f ide 7606001 A N 100 N 180 0.04 L 10 amph i bo Ii t e 76DG003A N 50 N 310 0.04 L L amph iboli te 7606007B N 150 N L 0.06 L 10 ca rbonate 76DGOOP8 N 150 N 15 0.30 15 55 sands tone 760G012A N 70 0.20 50 0.0? ?0 85 met agrayuacke 76DGC15A N 20 N 190 L 10 45 greenstone 760G016A N 100 N 40 0.0? 10 50 gr aywac ke 760G032A N 70 N 25 O.C? 10 «5 phylli te 760G036B N 30 N 1000 0.04 L 10 schist 760GC38A N 70 N 25 0.0? L 35 gne iss 76DG044A N 70 N 65 0.0? 30 85 si Itstone * Table B-8<. Anomalous bedrock qeocheraical samples collected by the Geoloqical Survey.-continued m Sample Lat i tude Longitude Aq (pom) As (pom) A u ( p Dffl ) R (ppm) Ba (ppm) Be (ppin) Bi (ppm) Ca (X) 76DGP52A 58 38 31N 137 24 58W N N N w L N N 7.00 G& 760G052I3 58 38 31N 137 24 58U N N N sn L N N 7.00 76DG055A 58 47 03N 137 36 02W M N N 70 500 1 N 3.00 76DG063A 58 46 50N 137 42 OOW N N N 70 100 L N 7.00 76DGP65A 58 46 23N 137 43 20W N N N sn 700 1 N 3.00 76DG065B 58 46 23N 137 43 20W L N N 70 L L N 7.00 41 76DG066B 58 46 16N 137 44 OOW 3.0 N N 70 700 L N 20.00 760GP67A 58 46 40N 137 44 29W N N N 50 700 L N 0.50 76RL1D6A 58 34 56N 137 00 27W N N N 20 L N N 3.00 76RL106B 58 34 56N 137 00 27W N N N ?0 L N N 3.00 76RL117A 58 34 56N 137 00 27W N N N 15 100 N N 7.00 & 77AFP47B 58 29 37N 137 09 10W N N N L L N N 1.50 77AFP47C 58 29 37N 137 09 10W N N N L L N N 0.70 77AF047D 58 29 37N 137 09 10W N N N L L N N 1.00 77AF050A 58 51 48N 137 38 03W N N N L 70 N N 1.00 w 77AFP51 A 58 49 03N 137 37 34W N N N L 30 N N 1.50 ^ i-i N N a* 77AF051B 58 49 03N 137 37 34W N N N L L 2.00 Ln 77AF053A 58 46 43N 137 28 26W N N N L 50 N N 2.00 77AF0538 58 46 43N 137 28 26W N N N L 500 1 N 1.50 77BJP08A 58 45 55N 137 45 51W 30.0 N 70 30 100 N N 3.00 77BJ008B 58 45 55N 137 45 51W 7.0 N L 30 100 N N 3.00 0 778J008C 58 45 55N 137 45 51W 15.0 N 30 L 300 N N 7.00 778J008D 58 45 55N 137 45 51W L N N L 300 N N 10.00 77BJP09A 58 45 48N 137 45 1 7W 1.5 N L 15 300 N N 1.50 773JPP9B 58 45 48N 137 45 17W N N N 15 300 N N 1.50 779JP11 A 58 52 23N 137 47 48W N N N 10 20 N 2.00 * 77RJ016C 58 28 49N 137 07 OOW N N N L L N 1.50 77BJ0160 58 28 49N 137 07 OOW N N N L L N 1.50 779JP21A 58 32 36N 137 16 08W N N N 15 L N 5.00 * 77BJ024A 58 50 30N 137 18 12W N N N L 1000 N 1.00 77BJ028B 58 53 40N 137 19 OOW N N N in 500 N 2.00 0 779JP31C 58 53 48N 137 16 45W N N N L 70 N 1.00 77BJP310 58 53 48N 137 16 45U N N N L 70 N 1.50 77BJP33B 58 53 05N 137 11 30W N N N 20 300 N O.?0 » 77BJ033C 58 53 05N 137 11 30W N N N 3n 500 N 0.70 77BJP37B 59 02 22N 137 08 06W N N 10 300 N 1.00 * 779J045A 58 55 34N 136 46 43W L t! L 150 N 5.00 77BJ045B 58 55 34N 136 46 43W L N L 1 50 N 5.00 77BJ046A 59 00 44N 137 05 15W 0.5 N L 500 N 1.00 * 77BJP46B S9 00 44N 137 05 15W 0.5 N L 500 N 1.00 779J046C 59 00 44N 137 05 15W L N 15 700 B 0.50 i£ 77BJ0460 59 00 44N 137 05 15W L N 10 700 P n.so Table P-Q.--Anoma(ous bedrock qeochemical samples collected by the Geoloqical Survey.-continued Sample Cd (pom) Co (pom) C r (ppm) Cu (pom) La (nom) (pom) (npm) Nb 76DG052A N so ?on 700 s.nn L 2. on t5nn N 76DG052B n 70 20 son 7.nn L 2.00 ?onn N 76DG055A N 15 150 70 p. on 20 1 .50 1500 N 76DG063A N 20 70 POO 3. on 20 2. on 2onn N 76DG065A N 15 150 30 2.00 50 1.50 1SOO N 76DG065B N 30 200 100 3.00 L 3. on 2nno N 76DG066B N 5 300 50 1 .00 L 1.50 I5no ?0 760G067A N 30 300 70 5.00 20 1.00 mno N 76RL106A N 50 700 300 15.00 20 10.00 1500 N 76RL106B N 150 700 300 10.00 20 7.00 1500 N 76RL117A N 150 500 50 3.nn ?0 7.00 1000 N 77AF047B N 70 2000 10 7.00 N 7.00 1000 N 77AF047C N 70 1500 30 5.nn N 7.00 700 N 77AFOA70 N 70 1500 100 7. on N 7.00 700 N 77AF050A N 50 70 150 7.00 N 1.50 moo N 77AF051A N 70 1SO 100 7.00 N 2.00 1500 N 7 77AF0518 N 50 300 70 5.00 N 2.00 mnn N 77AF053A N CTt 50 70 30 5.00 N ?. 00 1000 N CTt 77AF053B N 15 L 20 3.00 L 0.30 1000 N 778JP08A 30 L 50 7.00 N 2.00 1500 N 77BJ008B 30 L 30 7.00 N 2.00 1500 N * 77BJ008C 7 20 20 1.00 20 0.50 700 5 77BJ008D 5 70 15 1.00 20 0.50 700 L 77BJ009A 30 L 150 5.00 N 1.50 1500 N 778J009B 20 L 100 5.00 N 2.00 1500 N 77BJ011A 10 10 50 2. on ?n 0.70 moo N 77BJ016C 70 1500 50 7.00 N >io.on 700 N 77BJ0160 70 2000 70 7. on N >10.00 700 N 77BJ021A 70 300 700 7.00 N 2.00 1500 N 778J024A 15 70 15 3. on 30 L5n 1500 N 77BJ02PB 15 50 50 3. on 30 1.50 1500 N 77BJ031C 30 1000 50 ?.oo N 3.00 700 N 77BJ0310 50 700 50 3. on N 3.00 700 N 77BJP33B 7 30 10 ?.. 00 20 0.70 ?nn N 77BJ033C 20 100 ?n 0.30 20 1 .00 700 N 77BJ037B 10 L 1 50 ?.oo L 0.50 700 N 77BJ0^5A 70 N POO in. oo N 5.00 1000 N 77BJOA58 50 N 500 7.00 N 5. no 1000 N 778J(H6A 7 L 700 1.50 ?0 0.50 ?on N 77BJ046B 10 10 7no i.5n 20 0.50 500 15 77BJ046C 5 L 150 o.5n N 0.15 300 N 779JOA60 5 L 150 0.50 N n.15 3no N TableTab B-g. Anomalous bedrock geochemical samples collected by the Geological Survey.-centinued Sample N1 (ppm) Pb (ppm) Sb (ppm) Sc (ppm) Sn (ppm) Sr (opm) Ti (X) V (ppm) W (ppm) Y (pom) 760G052A 50 N N 30 N 300 0.500 200 N 20 in 760G052B 20 N N 50 N 100 1.000 200 N 70 760G055A 50 50 N 15 N 500 0.500 150 N 20 760G063A 30 L N 30 N 700 0.700 200 N 30 760G065A 30 15 N 15 N 500 0.700 100 N 20 760G065B 50 N N 50 N 200 0.500 ?00 N 20 fll 76DG066B 50 20 N 15 N 500 0.200 700 N 30 760G067A 7 20 N 20 N 100 0.500 100 N 30 76RL106A 700 N N 20 N N 0.070 50 N L * 76RL106B 700 N N 20 N L 0.070 50 N L 76PL117A 70 N N 70 N 300 0.150 500 N L * 77AF0478 1500 N N 20 N N 0.150 50 N 10 77AF047C 1500 N N 1 5 N N 0.150 50 N 10 77AF047D 1500 N N 15 N N 0.150 30 N 10 0 77AF050A 150 N N 30 N 100 1.000 200 N 20 ^^ txJ 77AF051 A 100 N N 50 N 300 0.700 300 N 30 ^y 1 77AFC51B 100 N N 50 N 100 0.500 200 N 20 H (Ti 77AF053A 70 L N 20 N 200 0.500 150 N 15 -JI 77AF0538 50 L N 20 N 300 0.500 20 N 30 ^ 778J008A 5 N N 50 N 300 0.700 300 N 20 77BJ0088 5 N N 50 N 300 0.700 200 N 20 77BJ011 A 5 N N 1 5 N 200 0.200 70 N 15 a 77BJ016C 700 N N ?0 N N 0.150 30 N 10 779J016D 1500 N N 30 N N 0.150 50 N 10 77BJ021A 100 N N 50 N L 0.500 200 N 30 ^ 77BJO?4 A 30 50 N 1 5 N 300 0.700 150 N 15 77BJP28B 30 50 N 15 N 300 0.500 150 N 15 *3I 77BJ031C 200 N N 20 N 200 0.200 50 N 10 77BJ0310 300 N N 15 N 300 0.300 70 N 10 77BJ0338 30 15 N 20 N 150 0.500 100 N 15 77BJ037B 5 15 N 7 N 150 0.300 20 N 15 ^ 779J045A 50 N N 70 N 300 0.700 300 N 10 77BJ045B 30 N N 70 N 300 0.700 200 N 10 77BJ046A 10 10 N 7 N 150 0.200 30 N 20 (9 77BJ0468 10 10 N 7 N 150 0.200 30 N 30 77PJ046C 5 70 N 5 N 100 0.070 10 N 15 til 77BJOA6D 5 50 N 5 N 100 0.070 10 N 20 «ft Table B-8. Anomalous bedrock qeochemical samples collected by the Geological Survey.-continued Sample Zn (ppm) Zr (ppm) Au (ppm) Cu (ppm) Hg (ppm) Pb (ppm) Zn (ppm) L1tholoqy 76DG052A N 30 N 650 L L 5 schist 76DG0528 N 50 N ABO N L 5 qneiss 76DG055A N 100 N 60 0.02 5 30 schist 76DG063A N 70 N 230 0.02 10 70 andesi te 76DG065A N 150 N 35 0.10 15 55 qranodior1te 760G065B N 30 N 170 0.08 15 70 qreenstone 76DG0668 N 30 N 40 L 20 H 140 si Itstone 76DG067A N 150 N 45 0.08 10 100 sandstone 76RL106A N N N 160 N 20 90 gabbro 76RL106B N N N 170 0.04 15 80 gabbro 76RL117A N L N 40 N 5 5 gabbro 77AF047B N 10 N 10 B 10 40 ultramafic 77AF047C N 10 N 35 B 15 40 ultrama fie 77AF047D N L N 90 B 10 45 ultramafi c 77AF050A N 50 N 130 B 10 70 schist CO 77AF051A N 70 N 95 B 5 15 schist 77AF051B N 20 N 100 B 5 10 schist CT> 77AF053A N 50 N 35 B 10 45 quart z di ori te 00 77AF053B N 100 0.25 30 B 5 55 quartz diorite d 77BJ008A N 20 68.00 35 B 15 40 di ori te 77BJ0088 N 20 19.00 ?5 B 15 35 diori te a 77BJQOEC N 30 28.00 35 B 15 H 60 Iimestone 77BJ008D N 20 6.00 30 B 25 H 40 I imestone 77BJ009A N 20 4.50 140 B 10 40 tonali te 77BJ009B N 15 2.00 130 R 10 45 tonaIi t* 77BJ011A N 30 1.00 95 8 10 45 quart z i te 77BJ016C N 10 N 50 B L 20 schist 77BJG16D N 10 N 60 H 10 25 schist 77BJ021A N 20 N 1300 B 5 10 cmei ss 778J024A L 70 N 10 R 10 110 schist 77BJ028B N 100 N 40 R 10 95 oneiss 77BJ031C N 30 N 75 R 10 30 granodior i te 77BJ031D N 30 N 70 R 10 45 qranodiori t» 77BJfl33B L 30 N 30 B 20 270 phyllite 77BJ033C N 100 N 20 B 15 60 graywacke 77BJ037B N 70 N 230 R 10 90 qranodiori te 77BJ045A N 15 N 300 B 5 30 amphiboli t e 77BJ0458 N 10 N 660 B 5 25 amphibolite 773J046A N 100 N 390 R 5 45 qranodior i te 77BJ046B N 100 N 8ftO B 5 40 pranodi or i te 77BJC46C N 30 N 110 R 5 10 tonali te 77BJP46D N 50 N 1*0 fl 5 10 tonaIi te Table B-8.--AnomaIous bedrock geochemical samples collected by the Geological Survey.-continued Sample Lati tude longitude Aq (ppm) As (npm) Au (opm) B (pom) Ba 77BJ046E 59 00 44N 137 05 15W 7.0 N N 10 700 L 8 1.00 41 778J046F 5" 00 44N 137 05 15W 15.0 N N 10 700 L B 0.70 778J047A 58 56 47N 137 04 25W N N N 50 700 L B 0.50 77BJ047B 58 56 47N 137 04 25W N N N 50 700 L P 0.50 77BJ048A 59 03 02N 136 58 10U N N N 15 200 L B 2.00 77BJ0488 59 03 02N 136 58 10U N N N 15 300 L B 2.00 9 77BJ050A 59 06 26N 136 50 29U N N N L 20 N B 20.00 778J0508 59 06 26N 136 50 29W N N N L 70 N B 20.00 77BJC50C 59 06 26N 136 50 29W N N N 50 300 N B 10.00 77BJ050D 59 06 26N 136 50 29W N N N 15 L N B 15.00 77BJ050E 59 06 26N 136 50 29U N N N 15 300 N B 2.00 77BJ050F 59 06 26N 136 50 29U N N N 10 500 L B 2.00 77BJ050H 59 06 26N 136 50 29W N N N 50 L N B 3,00 77DB044A 58 51 35N 137 47 05W N N N 10 100 L N 1.50 77D80478 58 39 30N 137 22 05U N N N L 700 N N 0.50 Cd 77D8050B 58 42 17N 137 27 51W N N N 10 L N N 5.00 M 770B051A 58 42 21N 137 21 19W L N N L 70 N N 5.00 77DB052A 58 42 56N 137 18 43U N N N L 20 N N 7.00 IP 77080528 58 42 56N 137 18 43W N N N L L N N 5.00 77DB052C 58 42 56N 137 18 43W N N M L 20 N N 7.00 770B052D 58 42 56N 137 18 43W N N N L 30 N N 7.00 9 770B053A 58 44 39N 137 24 33U L N N 10 150 N N 5.00 770B053B 58 44 39M 137 24 33U L N N 10 100 N N 5.00 770B058F 58 47 52N 137 37 34U N N N L L N N 3.00 77DB058G 58 47 52N 137 37 34w N N N L L N N 3.00 770B059A 58 53 54N 137 46 48U N N N 10 100 N N 2.00 £ 77DB066A 58 45 01N 137 30 36U N N N 10 L N N 3.00 770B066B 58 45 01N 137 30 36U N N M 10 L N N 5.00 77DB066C 58 45 01N 137 30 36U N N N 10 L N N 5.00 77DB066D 58 45 01N 137 30 36W N N N 10 L N N 5.00 77PB0678 58 44 07N 137 31 07W N N 15 L N N 5.00 ft 770B068E 58 48 22N 137 29 30W N N ?0 300 N N 5.00 770B073A 58 52 07N 137 36 29W N N 10 20 N N 3.00 77DB074C 58 43 21N 137 19 48U 0.7 N 15 L N N 3.00 * 770B074D 58 43 21N 137 19 48U 1.0 N L N N 3.00 77DBC174E 58 43 21N 137 19 48W N N L L N N 3.00 » 77DB074F 58 43 21N 137 19 48U n N 10 L N N 2.00 77DB076B 58 39 42N 137 15 28W N N 10 L N N 3.00 770B087C 58 59 10N 137 03 now N N 10 30 N N 3.00 * 77DP087D 58 59 ION 137 03 OOU N N 10 50 N N 2.00 770B088B 58 59 33N 137 02 22U N N 10 20 N N 3.00 40 770B089A 59 00 OON 137 02 58U N N 10 50 N N 2.00 Table 8-$.--Anomalous bedrock geochemical samples collected by the Geological Survey.-continued Sample Cd (pom) Co (ppm) Cr (ppm) Cu (pom) Fe (X) La (opm) Mq (X) Mn (pom) Mo (opm) Nb (opm) 77BJ046E N 15 50 5000 3.00 L 1.50 500 N N 77BJ046F N 10 30 10000 2.00 L 1.00 77BJ047A 500 N N N 10 70 70 3.00 20 1.50 1000 77BJ047B N 15 N N 100 50 3.00 L 1.50 1000 N O 77BJ048A N 15 L 30 N 3.00 L 1.50 1500 N N 77BJ048B N 15 L 30 3.00 77BJ050A L 1.50 1000 N N * N 7 10 5 1.00 N 77BJ0508 2.00 200 N N N 5 L 10 0.30 N 1.00 77BJ050C N 10 10 300 N N 10 2.00 L 1.50 700 N 77BJ0500 N 10 10 5 N 3.00 L 1.50 700 N N 77BJ050E N 15 70 5 2.00 20 77BJ050F 1.50 1000 ft N 15 70 15 2.00 20 1.50 1000 V 77BJ050H N 15 10 30 N "J 3.00 L 1.00 1000 77DB044A N 30 30 100 7.00 77DB047B N 1.50 1000 N 50 70 15 5.00 20 1.00 3000 770B050B N 100 700 150 10.00 N 3.00 . 1500 770B051A N 100 300 700 10.00 N 77DB052A N 2.00 1500 N N 50 700 70 5.00 N 3.00 77DB0528 N 700 N 70 700 150 7.00 N 5.00 1000 77DB052C N 50 500 50 N 5.00 N 5.00 1000 N 770B0520 N 30 300 50 2.00 N 3.00 700 770B053A N 50 200 150 N 10.00 N 3.00 1500 N 770B053B N 70 300 200 10.00 77DB058F N 3.00 ?noo N N 50 300 500 5.00 N 2.00 1500 770B058G N 70 200 200 N 5.00 N 3.00 1500 N 770B059A N 50 30 500 '7.00 N 2.00 1500 770B066A N 100 3000 150 N 10.00 N 5.00 1000 N 770B066B N 70 2000 500 10.00 77DB066C N 5.00 1000 N N 70 2000 5 7.00 N 7.00 1500 77DB0660 N 70 2000 7 N 10.00 N 7.00 1000 N 77DB067B N 70 1500 150 7.00 N 5.00 1500 770B068E N 50 500 150 N 7.00 N 2.00 1500 N 77DBP73A N 100 150 150 10.00 77D6074C N 1.50 1500 N N 100 700 700 7.00 N 5.00 1500 770B0740 N 150 1500 3000 N 10.00 N 7.00 1500 N 77DR074E N 70 1500 50 5.00 77DB074F N 7.00 1000 N N 100 1500 150 7.00 N 770P0768 7. 00 700 N N 70 700 100 7.00 N 770B087C 3.00 2000 N N 50 200 70 5.00 H 1.50 1000 77080870 N 70 N 200 50 5.00 N 1.50 1000 N 770B088B N 50 300 70 7.00 N 2.00 1000 77DB089A N 30 300 N 50 s.oo N 2.00 1000 N Table B-0.--AnomaIous bedrock geochemical samples collected by the Geological Survey.-cootinued Sample Ni (ppm) Pb (pom) Sb (ppm) Sc (pom) Sn (opm) Sr (pom) M (ppm) W (pom) Y (po«) 77BJ046E 50 L N 10 15 200 0.300 50 L 15 77BJOA6F 15 10 N 10 70 150 0.200 30 150 15 779J047A 50 15 N 20 70 300 0.500 150 N 30 779J047B 50 L N 20 70 ?00 0.700 150 N 20 77BJ048A 5 L N 15 70 700 0.500 100 N 20 77BJ048B 5 L N 1 5 70 moo 0.500 100 N 20 778J050A 20 L N L 70 700 0.020 15 N L 773J050B 10 L N L 70 700 0.015 15 N L 778J050C 10 L N 7 70 500 0.150 50 N 15 77BJ0500 10 N N 7 70 300 0.150 30 N 15 77BJ050E 30 L N 15 70 500 0.300 70 N 20 77BJ050F 30 L N 15 70 500 0.300 70 N 20 77BJ050H 15 L N 20 N 100 0.500 200 N 30 770BOAAA 30 N N 30 N 300 0.300 200 N 10 77DB047B 100 10 N ?0 N 200 0.500 150 N 20 W 770B050B 150 N N 70 N L 0.500 200 N 20 770B051 A 100 N N 50 N 200 1 .000 300 N 30 770B052A 100 N N 50 N 150 0.200 300 N L 770B052B 200 N N 30 N 150 0.200 150 N 10 770B052C 100 N N ?0 N 200 0.200 150 N L 770B0520 70 N N 30 N 200 0.150 100 N L 770B053A 70 N N 50 N 200 > 1 . 000 " 100 N 30 770B053B 100 N N 20 N 150 > 1.000 200 N 30 770B058F 70 N N 70 N L 1.000 200 N 30 770B058G 70 N N 70 N L 0.700 200 N 30 770B059A 70 N N SO N 1 50 0.700 ?00 N 30 770B066A 1500 N N 30 N N 0.500 no N 15 770B066B 700 N N 50 N L 0.500 150 N 20 770B066C 1000 N N 50 N L 0.300 100 N 20 77DB066D 1500 N N 50 N 100 0.300 100 N 30 770B0678 300 N N 15 N 100 0.500 100 N 20 77DB068E 50 L N 50 H 300 0.500 150 N 30 770B073A 70 N N 70 N N 1 .000 200 N 30 77DB074C 500 N N 50 N N 0.100 70 N L 77DB074D 1500 N N 70 N N 0.200 100 N 10 77D8074E 300 N N 20 N L 0.100 30 N L 77DB074F 1000 N N ?0 N t 0.100 50 N L 770B076B 150 N N 100 N L 1.000 500 N 15 770BOR7C 150 L N 30 N 200 1.000 150 N 30 770B0870 150 N N 30 N 150 1.000 150 N 30 770B0888 70 N N 50 N 100 1.000 150 N 30 770B089A 100 N N 30 N L 0.500 100 N 20 Table 9- 8. --Anomalous bedrock aeochemical samples collected by the Geoloqical Survey.-continued Sample Z n (ppm) Zr (opm) An (ppm) Cu (ppm) Hcj (pom) Ph (com) 7n (ppm) Li t holoav 779J046E N 50 0.10 5SOO 10 70 quartz monzodiorite 779J046F N 50 n.25 14000 5 1 40 quartz monzodiorite 77BJP47A N 70 N 75 ?0 ' «575 DhylU te 77BJ047B N 70 N 40 15 phvtlite 779J048A N 70 N 40 5 70 quart z di ori t e 77BJP48B N 30 N AO 5 55 Quart z di ori te 77BJ050A N 10 N ?5 30 H 5 Ii mestone 77BJ050B N 10 N AO 35 H 35 I ines tone 779J050C N 30 N 20 20 H 10 chert 77BJ050D N 30 N 10 ?0 H ?0 chert 77BJ050E N 30 N 10 10 30 diorite 77BJ050F N 50 N ?5 10 ?5 dlori te 77BJ050H N 30 N ?5 15 45 quartzite 77DB044A N N N 60 15 50 di ori te 77DB047B L 70 N 15 20 120 diorite 770BP508 N ?0 M HO 10 10 schist 77DB051A N 30 N 640 5 10 schist 77DB052A N 10 N 60 10 10 gahbro 77DB052B N 10 N 170 5 15 qahbro 77DB052C N 10 N 75 10 5 gabbro 770BC520 M L N 35 10 5 qabbro 77DB053A N 70 N 1?0 5 10 schist 77DB053B N 70 N 260 L 10 schist 77DB058F N 50 N 430 L 10 qne i ss 77DB058G N 50 N 320 5 5 qne i ss 77DBP59A N 50 N 360 L 25 one i ss 77DB066A N 10 N 140 5 10 schi st 7708066B N 15 N ?QO 5 10 schist 77DBP66C N 20 N 5 5 20 schist 77DB0660 N 15 N 5 L ?0 schist 770B067B N 20 N 150 5 15 schist 770B068E t 30 N 65 25 an qr eenschist 770B073A N 50 N 200 L 10 qnei ss 770B074C N L N 1000 15 45 pyroxeni te 77DB074D N L N 240.0 10 60 py roxeni t.e 77DB074E N N N 110 15 40 qabbro 77DB074F N N M 75 15 25 qabbro 77DB076B N 10 N 60 L 10 qabbro 770B087C N 70 N 50 10 65 qreenstone 77DB087D N 70 N 40 5 80 qreenstone 770B088B N 30 N 70 10 60 qreenstone 77DB089A N 30 N 55 5 S5 qreens tone Table B-8. Anomalous bedrock geochemical samples collected by the Geological Survey.-continued Sample Latitude Lonqitude Aq (ppm) As (pom) Au (ppm) B (ppm) fla (ppm) Be (ppw) Bi (pom) Ca (X) 770B089B 59 00 OON 137 02 58U N N N L 70 N N sloo 770B090B 59 00 19N 137 03 09W N N N 10 700 N N 2.00 77DB097A 58 A3 A3N 137 03 59W N N N N 100 5 N 0.20 77DB097B 58 A3 A3N 137 03 59W N N N N 300 3 N 0,20 770B097D 58 A3 A3N 137 03 59W N N N 70 1500 L N 0.70 770B098B 58 58 01N 137 02 A1W N N N 20 1000 L N 1.00 770BC99C 58 59 30N 137 OA 13W N N N 50 500 N N 1.00 77DB0990 58 59 30N 137 OA 13W N N N ion 500 L N 1.00 770B101C 59 OA 16N 136 53 12W N N N N 700 5 N 0.50 770B101D 59 OA 16N 136 53 12W N N N N 700 7 N 0.20 770B102A 59 05 38N 136 56 10W N N N 10 300 5 N 2.00 77RM011 A 58 42 16N 137 2A 03U N N N 20 500 L N O f 70 77Rf013C 58 AO 01N 137 19 07W N N N 10 100 N N 2.00 77RM01 AA 58 29 08N 137 09 30W N N N L L N N 5.00 77RM030A 58 37 47N 136 21 39W N N N 15 500 N N 5.00 ttl 77RM030B 58 37 47N 136 21 39W N N N 1S 300 N N 3.00 77RM032C 58 39 51N 136 29 50W L N N L 300 N N 0.70 77RM032D 58 39 51N 136 29 SOW L N N L 700 L N 0.70 co 77RM033B 58 A2 A8N 136 25 A7W N N N L 1000 L N 2.00 77RM036B 58 A8 35N 136 A3 09W N N N 20 300 N N 2.00 77RM038C 58 21 26N 136 30 06W L N N 10 30 N N sloo 77RM0380 58 21 26N 136 30 06U N N N m 30 L N 3.00 77RM040B 58 50 17N 137 10 32W N N N 15 700 L N 1.00 77RM062B 58 58 52N 137 07 10W N N N 20 1000 N N 1.50 77RI«062C 58 58 52N 137 07 10W N N N 10 300 N N 3.00 77RM0620 58 58 52N 137 07 10U N N N 10 300 L N 00 77RH063B 59 01 03N 137 09 03W N N N L 700 L N 50 77RM069A 58 58 15N 137 01 15W N N N 30 50 N N 00 77RW069B 58 58 15N 137 01 15W N N N 20 100 N N 00 77RM071C 58 58 A7N 137 01 09W L N N 10 300 N N 00 77RW071D 58 58 47N 137 01 09U N N N 10 300 N N 1.50 77RM073C 58 59 14N 137 01 02W N N N 10 500 N N 7.00 * * Table B-#. Anomalous bedrock geochemical samples collected by the Geological Survey.-continued Sample Cd (pom) Co (ppm) Cr (ppm) Cu (oom) Fe (X) La (ppm) Mg (X) Mn (ppm) (ppm) Nb (pp») 77DB089B N 30 300 50 5.00 N 2.00 700 N N 77DB090B N 50 150 50 5.00 N 2.00 1000 N N ' N 770B097A N N L L 0.50 N 0.02 iono L 77080978 N N L L 0.50 N 0.02 700 N L 770B097D N 15 50 150 3.00 20 1.00 iono N N 77DB098B N 5 L L 1.50 20 0.70 1500 N N 770B099C N 20 50 70 5.00 L 2.00 1000 N N 77DBP99D N 50 200 70 7.00 L 2.00 1000 N N 770B101C N N L 5 0.70 70 0.07 700 N L 77DB101D N N L L 1.00 70 0.07 700 5 L 77DB102A N 20 L 7 5.on L 1.50 1500 N N 77RM011A N 15 50 150 3.00 ?0 1.00 2000 N N 77RM013C N 50 L ?00 on N 1.50 1500 N N 77RM014A N 70 30 150 00 N 2.00 1000 N N 77RM030A N 70 700 150 on N 2.00 1000 N N 77RM030B N 70 1000 100 7.nn N 3.00 1000 N N 77RW032C N 5 50 20 0.70 20 0.50 300 100 N 77RM032D N 5 50 20 0.70 ?0 0.70 500 100 N 77RM033B N 10 L 30 1.50 20 0.70 700 N N 77RM036B N 50 300 70 5.00 L ?.oo 1000 N N 77RM038C N 15 L 700 1 .50 N 0.70 700 N N 77RM038D N 15 L 700 1.00 L 0.50 700 N N 77RM040B N 30 300 20 5.00 20 1.50 1000 N N 77RI»062B N 30 70 150 5.00 20 3.00 2000 N N 77RM062C N 50 700 150 7.on N 3.00 1500 N N 77RW062D 50 500 150 7.00 N 1.00 1500 N N 77RMC63B 30 50 50 no 20 1.00 1000 N N 77PM069A 30 150 150 00 N .50 1000 N N 77RM069B 50 150 150 no N .50 1500 N N 77RM071C 30 70 200 nn N .50 1000 N N 77RM071D 30 L 150 7.on N .50 1500 N N 77RM073C 15 100 L ?.no L .50 1000 N N * * Table B-8. Anomalous bedrock geochemical samples collected by the Seoloqical Survey.-eontinued Sample Ni (ppm) Pb (ppir) Sb (ppm) Sc (ppm) Sn (ppm) Sr (ppm) Ti (X) V (ppm) W (ppm) V (ppm) 770B0898 100 N N 30 N 100 0.500 100 N 20 77D8090B 100 N N 30 N L 0.700 150 N 30 770B097A L 50 N 5 L N 0.015 10 N 20 770B0978 L 50 N 5 L N 0.015 L N 30 770B0970 30 30 N 20 N ?00 0.700 150 N 20 770B0988 L L N 7 N 300 0.300 20 N 15 770B099C 100 L N 20 N 200 0.500 100 N 15 77DB0990 150 N N 20 N 300 1 .000 150 N 30 770B101C L 30 N 5 L L 0.100 L N 20 77DB1010 L 20 N 7 L L 0.150 L N 30 770B102A 30 L N 20 N 700 0.700 150 N 20 77RM011 A 70 10 N 15 N 300 0.500 100 N 20 77RM013C 20 N N 30 N 100 0.700 150 N 20 77RMOUA 70 N N 50 N L 0.070 100 N L 77RM030A 150 N N 50 N 500 0.500 150 N 20 tx» 77RM030B 150 N N 50 N 500 0.500 150 N ?0 77RM032C 30 L N 10 N 100 0.300 700 N 15 77RM032D 20 L N 10 N 100 0.200 1000 N 15 77RM033B 70 L N 15 N 500 0.500 150 N 15 77RM036B 70 N N 30 N 500 0.700 150 N 20 77RM03BC 15 N N 15 N 1000 '0.150 50 N 10 77RMP38D 10 N N 10 N 1000 0.150 50 N 10 77RM0408 100 15 N 20 N POO 0.700 150 N 30 77RM0628 50 L N 20 N 300 0.700 150 N 20 77RM062C 150 N N 30 N 200 0.700 150 N 20 77RM0620 200 N N 30 N 150 0.500 70 N 15 77RMC63B 70 L N ?0 N 200 0.700 150 N 30 77RM069A 70 N N 30 N 200 1.000 200 N 30 77RM069B 70 N N 30 N ?00 > 1.000 200 N 30 77RM071C 15 N N 30 N 200 0.300 200 N 20 77RM071D 7 N N 30 N 200 0.500 150 N 20 77RM073C 100 L N 15 N 500 0.500 150 N 20 i Table B-8. Anomalous bedrock geochemical samples collected by the Geological Survey.-continued 1 Sample Zn (ppm) Zr (ppm) Au (ppm) Cu (ppm) Hg (ppm) Pb (ppm) Zn (DO*) Lithology 770B089B N 70 N 55 5 45 greenstone 1 770B090B N 50 N 40 5 60 greenstone 770B097A N 30 N 5 5 40 grani te 770B097B N 50 N 5 5 40 granite * 770B0970 200 70 N 65 10 100 semi schist 77080988 N 70 0.15 5 5 45 granodi ori te 1 770P099C N 50 N 60 15 100 quartzite 77060990 N 70 N 40 10 85 quartzite 770B101C N 70 N 5 L 25 grani te 1 770B1010 N 100 0.15 5 L 30 grani te 770B102A N 30 N 10 L 30 gneiss 1 77RM011 A L 50 N 130 10 80 schist 77RM013C N 30 N 500 5 15 gnei ss 77RI*014A N N N 310 5 L gneiss 1 77RK030A N 30 N 140 10 20 gneiss w 77RM030B N 30 N 110 10 20 gneiss 1 1 77RM032C N N N 30 5 50 hornfels !^ 77RM032D N 70 N 30 5 45 hornfels <* 77RM033B N 70 N 50 5 30 diori te 1 77RM036B N 70 N 55 20 55 greenstone 77RM038C N N N 620 10 30 diori te 1 77RM0380 N N N 1000 10 15 diori te 77RM040B N 70 N 10 5 80 semischist 77RM062B N 70 N 85 25 100 conglomerate 1 77RM062C N 30 N 85 20 60 di abase 77RM062D N 30 N 90 20 55 di aba se 77RM063B N 70 N 30 5 45 granodiori te 1 77RM069A N 30 N 190 15 75 greenstone 77RM069B N 70 N 200 15 80 greenstone 1 77RM071C N 10 N 390 10 85 granodior i te 77RM071D N 30 N 70 20 60 granodior i te * 77RM073C N 70 N 5 15 20 brecc ia » AnalysAnalysis i s by atomic absorption/ all others by semi quantitative spectrographic methods K iw^tc-it 1 <\ 3 L mcUc-a e i ^K\ e« The average abundance of the elements of interest in the rocks of the area is quite similar to crustal averages (Levinson/ 1974) with a few minor exceptions (table B-9). Elements which seem to be slightly low include TABLE B-9 NEAR HERE beryllium, nickel, lead, and zinc. None of the elements of economic interest in the study area appear to be above average crustal abundance. Table B-10 also contains comparisons of some of the bedrock geochemical units with average crustal abundances of similar rock types. The average geochemical values of the granitic rocks in the study area are very similar to the average crustal granodiorite with the exception of beryllium, copper, nickel, and zinc, which appear to be slightly low. The average geochemical values for the hornblende-bearing metamorphic unit are quite similar to the average crustal basalt with only nickel and zinc being significantly low. The average geochemical values for the layered gabbro unit are also quite similar to the average crustal basalt and predictably different from the average ultramafic rock. Only zinc appears to be quite low compared with average basalt. In general, it appears from these analyses as if the study area as a whole is slightly deficient in zinc and perhaps chromium and nickel compared with crustal averages. There are no metallic elements which appear to be significantly above average crustal abundance. B-177 Table B- 9 Comparison of average crustal abundances of selected elements with approximate means of rock geochemical units, in parts per million. [Analyses for this study by semiquantitative spectrographic methods, except Au, Hg, and Zn by atomic absorption and U by wet-chemical methods] Average .Layered Average JHornblende - Average Granite Crustal Study - bearing Element Ultramafic "Gabbros Basalt-/ Metamorphic Granodiorite Rocks Average Average rocks Ag 0.06 «0.05 0.1 «0.5 0.07 «0.5 0.07 «0.5 Be .5 «1 2 <1 2.8 <1 Co 150 47 50 35 10 15 25 20 Cr 2000 150 200 150 20 10 100 70 Cu 10 110 100 70 30 15 55 40 oo Mo . 3 1 «5 1 «5 1.5 «5 Ni 2000 100 150 60 20 6 75 30 Pb .1 . 5 <10 15 10 12.5 <10 Sn .5 1 . 2 «10 2 «10 W .5 1 2 1.5 «50 Au .005 .004 «.05 .004 «.05 .004 «.05 Hg .03 .08 .03 .08 .03 .08 .03 Zn 50 13 100 11 60 35 70 30 l£/ 2.7 1.7 average from Levinson (1974). Uranium analyses were not reported for specific rock Rock Geochemical Anomalies The distribution of rock geochemical samples within the Monument is uneven (see plate 2). The western half of the Monument is moderately well covered considering the large areas of ice and water in the central portion of the Monument. However, coverage in the eastern half is poor to nonexistent. At least partly, for this reason, the majority of the anomalous rock samples occur along the western edge of the area. The impressive belt of anomalous stream-sediment samples near Excursion Inlet is represented by two small rock anomalies (figure B-20, areas 9, 10). The lack of anomalous rock samples in this large area of anomalous stream-sediment samples FIGURE B-20 NEAR HERE is probably due to a lack of samples. The anomalous rock samples were determined for each rock geochemical unit independently. Sample locations were combined to form the anomalous area map shown in figure B-20 and described below. It should be emphasized that the term anomalous pertains to a statistical process that involves the 95th percentile of the reported values for the various elements and a comparison with the normal geo chemical abundances for those elements. This section attempts to relate B-179 Hg Ag,Au,Cr Hg,N5,Pb Sn.W 59° 00- t_ Figure B-20.--Map of Glacier Bay National Monument showing major geographic features, intrusive bodies, and areas containing anomalous rock geo- chemical samples. Labels show metallic elements that are anomalous in each area. B-180 196 59* 00 9»* SO' Figure B-20. Continued (two of two). B-181 individual rock geochemical analyses to mineralization. In some cases, anomalous rocks can be explained as specific rock types with higher background metal content than the generalized rock unit used to define the anomaly. In these cases, the term anomalous becomes a relict of the initial data manipulation and is unrelated to mineralization. Desolation Valley (fig. B-20, area 1) This is a large area approximately centered on Desolation Valley which stretches from north of Fairweather Glacier to south of Lituya Bay and from the coast inland as far as Mount Orville. The entire area is characterized by anomalous copper, nickel, chromium and locally cobalt which cannot easily be ex plained except perhaps as material contributed by or associated with either the layered gabbro bodies or hornblende-bearing metamorphic rocks east of the Fairweather fault. A smaller, elongate area along Desolation Valley from Lituya Glacier to South Crillon Glacier is anomalous in silver, gold, lead, zinc, molybdenum, and mercury; there is a small gold anomaly southwest of Lituya Mountain; and the vicinity of Mount Escures is anomalous in gold, silver, and mercury. Some of the anomalous rocks in this area appear to be related to intrusive bodies and suggest that polymetallic mineralization may be the main source of metals in the rocks. Coastal (fig. B-20, area 2) This area is primarily along the low coastal hills between Crillon Lake and Finger Glacier. It is characterized by anomalous chromium, nickel, and locally copper and gold. The origin of the anomalous rocks in this area is probably similar to the origins described for area 1 above. B-182 Dixon River (fig. B-20, area 3) This is a large, irregular shaped area approximately centered on the Dixon River. The area contains numerous evenly distributed samples anomalous in copper, lead, chromium, and nickel. The northern end also contains samples anomalous in cobalt. These anomalous samples are apparently related to the gabbro and hornblende schist and gneiss in the area. Blackthorn Peak (fig. B-2Q, area 4) This is a small area directly east of the Geikie Glacier which is anomalous in copper and nickel.. The area contains outcrops of Cretaceous migmatites but the anomalous metal content cannot be easily explained. Tarr Inlet (fig. B-20, area 5) This is a relatively smaill area with persistently high values of gold, silver, copper, lead, nickel, chromium, mercury, tungsten, and tin. The area includes rocks west of Tarr Inlet and from the Monument boundary on the north nearly to Johns Hopkins Inlet on the south. Significant mineralization is found in surface outcrops in this area and appears to be related to shearing and intrusion along the Tarr Inlet suture zone arkd To volcume rtscKs of 1%ttvtianf?) Mount Barnard (fig. B-20, area 6) This is a small area northeast of Tarr Inlet which is characterized by anomalous copper and mercury at the eastern end and anomalous gold and beryllium at the western end. These anomalous metals are probably related to granitic plutons in the vicinity. B-183 Wachusett Inlet (fig. B- 20, area 7) This is a small area along Wachusett Inlet and Idaho Ridge which contains anomalous copper, nickel, mercury, and tungsten that is probably related to a large granodiorite pluton. Hugh Miller Mountain (fig. B-20, area 8) This small area centered on Hugh Miller Mountain is slightly anomalous in nickel and mercury which are probably related to minor mineralization along the margin of a large tonalite body. Excursion River - Excursion Inlet (fig. B-20, areas 9 and 10) The few rock samples collected in this area are anomalous in nickel and either copper or gold. They may be related to a large anomalous belt of stream-sediment samples that is discussed below. Stream Sediment Anomalies Although the area provided few rock geochemical samples with values which varied greatly from normal crustal averages, there are many areas in which the stream-sediment values are greater than would be expected from the background metal content of the rocks alone. These areas with anomalously high stream-sediment concentrations are depicted on figure B-2 land described below. FIGURE B- 21 NEAR HERE B-184 It should be emphasized again that the terms anomalous and distinctly anomalous /pertain to a statistical process involving the 95th and 98th percentile of the reported values for the various elements and a com parison with the normal geochemical abundances for those elements. This section attempts to relate the stream sediment .anomalies to the nearby rocks and mineral deposits. In some cases, the anomalies can be explained by the occurrence of particular rock types in the area. In these cases, the term anomalous becomes a relict of the data manipulation and is unrelated to mineralization. Fairweather Glacier (fig. B-21, area 1) The Fairweather Glacier area is a small area northwest of the Fairweather Glacier which is anomalous in chromium, copper, nickel, and zinc. The anomalous chromium and nickel values are almost certainly related to the layered gabbro and peridotite at Mt. Fairweather. The anomalous copper may also be related to these rocks. However, anomalous zinc values and possibly copper values cannot be explained by the normal background metal content of any rocks in the area and may be due to undiscovered mineralization. Mount Escures (fig. B-21, area 2) The Mount Escures area is a small -area on the south side of Mount Escures which is anomalous in cobalt, mercury, and locally chromium and zinc. The anomalous chromium and cobalt values are probably related to the layered gabbro and peridotite at Mt. Fairweather. This area was probably covered at" one time by glacial debris from the Fairweather Range. The anomalous zinc and mercury values cannot be explained by the normal background metal content of any rocks now in the area. They may be partially derived from a small group of mafic dikes located just south of Mount Escures or may be due to undiscovered B-ISS' Figure B-21. Map of Glacier Bay National Monument showing major geographic features, intrusive bodies, and areas containing anomalous stream-sediment samples. Labels show metallic elements that are anomalous in each area. Elements in parentheses probably derived from normal background amounts of elements in particular rock units. B-186 -V4*"""".*, - 3»' 00 g,Cu,Pb,Zn Ag, Au, Cu,Pb, Be,Co, Hg, Ni) ' 30' o, Cu.Pb, n^Be, Hg) Figure B-21. Continued (two of two). mineralization. Crillon Inlet! (fig. B-21, area 3) This is another small area centered around Crillon Inlet and the head of Lituya Bay which is anomalous in chromium and copper. The anomalous values are probably related to the layered gabbro bodies to the east. Mount Marchainville (fig. B-21, area 4) The Mount Marchainville area extends from La Perouse Glacier on the northwest to the Deception Lakes to the southeast and averages about 10 kilometers in width. The area is anomalous in chromium, copper/ and locally beryllium. The anomalous chromium and copper values are probably derived both from extensive layered mafic metamorphic rocks and from the large layered gabbro body to the north. It should be noted that the Brady Glacier nickel-copper deposit, just north of the center of the area, has no geochemical effect over that to be expected from the layered gabbros in the area. The local high beryllium values are probably derived from granitic rocks in the area. Rendu Gabbro (fig. B-21, area 5) This is a very small area northeast of Rendu Inlet which is anomalous in chromium. The anomalous chromium values may be derived from a very small serpentine and gabbro body. Johns Hopkins Inlet (fig. B-21, area 6) This area extends from the southeastern side of upper Johns Hopkins Inlet to Reid Inlet and contains the Reid Inlet gold area. The area is anomalous in gold, copper, and beryllium. The anomalous beryllium samples are confined to a small area along the southeastern shore of upper Johns Hopkins Inlet B-188 and are probably derived from nearby granites. The anomalous gold and copper samples occur within the Reid Inlet gold area amongst many old mining prospects and are probably related to mineralization in them. Dundas Bay (fig. B-21, area 7) This is a large anomalous area which generally covers Dundas Bay with an eastern extension north of Point Dundas. The area is anomalous in mercury, copper, cobalt, zinc, lead, and beryllium. The mercury anomaly closely follows the outlines of the bay and is possibly related to human habitation and contamination. Anomalous beryllium samples are confined to the northwest portion of the area and may be derived from local granitic intrusives. The eastern end of the area is anomalous in copper, lead, and zinc. These samples occur near the margin of a tonalite intrusive and may be derived from minor mineralization associated with intrusion*L. The southwestern corner of anomalous the area is anomalous in copper and cobalt. The / samples occur near a granodiorite pluton and may be derived from material related to minor mineralization associated with the pluton. They may also have been de rived from glacially transported layered gabbro and hornblende schist and gneiss carried across the Brady Glacier from the west. Table Mountain (fig. B-21, area 8) This area consists of most of the area of low hills southwest of Taylor Bay. The area is anomalous in zinc and mercury. The origin of this anomalous material is unknown. Mount Merriam (fig. B-21, area 9) This area consists of most of the drainage area of Mount Merriam and Blackcap Mountain and is anomalous in lead and silver. Most of the area is covered by a broad, B-189 weak lead anomaly with a very small silver anomaly in the eastern corner. The anomalous material may be derived from mineralization related to a large granodiorite pluton to the northeast. Muir Inlet Molybdenum Province (fig. B-21, area 10) This is a large area of scattered samples with anomalously high molybdenum content. The area contains at least one^molybdenum\porphyry^/deposit , the Nunatak molybdenum prospect. The entire area is near the periphery of several large granitic plutons associated with smaller granitic bodies. The high molybdenum content of the sediment samples is probably derived from mineralization related to these bodies. The large area of anomalous molybdenum in stream sediments suggests that additional porphyry molybdenum deposits occur in the area. Berg Mountain (fig. B-21, area 11) This anomalous area partially overlaps the Muir Inlet molybdenum province? however, the anomalous metals differ. The area is anomalous in chromium, nickel, lead, and zinc. The area which overlaps area 10 also contains anomalous molybdenum values. Each of the three "corners" of the area contains a small lead-zinc anomaly. The western lead-zinc anomaly, near Snow Dome, may be derived from miner alized zones near the margin of a large granodiorite pluton. Two eastern areas anomalous in lead-zinc are contained within a larger area which is anomalous in nickel and chromium. This entire area, which is anomalous in nickel, chromium, lead, and zinc, occurs within a large body of mafic volcanic rocks and may reflect either their normal background trace metal content or undiscovered mineralization. B-190 Willoughby Island (fig. B-21, area 12) This area, which consists mostly of carbonates on Willougby Island and Francis Island, is anomalous in lead and zinc. The lead anomaly covers both islands and the zinc anomaly is confined to Francis Island. A small portion of a diorite intrusion which extends out to Francis Island from south of Marble Mountain is likely to be the source of the mineralization which produces this anomaly / but stratabound deposits could also occur. . . .Mount. Wright: .to Excursion .Inlet (fig. B-21, areas 13, 14, 15) These three areas make up a large continuous belt of anomalous stream- sediment samples. The northern and southern areas (13 and 15) have quite similar geochemical anomalies while the central area (14) is slightly different. The northern area (13) and the southern area (15) are characterized by strongly anomalous copper, lead, nickel, and cobalt. In addition, area 13 has a somewhat smaller chromium anomaly in the northern portion, a mercury anomaly on the northwest side of Miller Peak, and a small molybdenum anomaly along the western border of the area. In addition to these anomalies, the southern area (15) contains a subarea that extends from the mouth of the Excursion River northeast to the Monument boundary which is anomalous in gold, silver, zinc, and beryllium, a subarea along the western edge of Excursion Inlet which is anomalous in mercury, and a central subarea with anomalous beryllium. The central area of this anomalous belt (14) is characterized by a zinc anomaly covering the entire area and overlapping the Miller Peak and upper Excursion River areas. In addition, it contains two small silver B-191 anomalies at the eastern and western edges, and a central zone anomalous in copper and lead. In summary, the continuous belt of anomalous stream-sediment samples which occurs between Mount Wright and Excursion Inlet is anomalous in every element selected for study and is the most important area delin eated in the stream-sediment survey. The association of chromium, nickel, and cobalt suggests the presence of one or more undiscovered ultramafic or mafic bodies in the area. Although the origin of the anomalies in the rest of the metals is unknown, the relationship of other nearby mineralization to plutonic rocks suggests that the anomalous material is similarly related to one or more shallow (or undiscovered) felsic plutons. There is little other evidence to support this hypothesis. The area is densely covered by vegetation/, rock outcrops are sparse, and no prospects ^ are known in the area. However, aeromagnetic data substantiates the presence of shallow felsic plutons (see Interpretation of Aeromagnetic Data, this chapter) . Uranium Analyses There has been no -production of uranium from this area, nor is there any prospect that contains uranium in substantial quantity. All of the rock and stream-sediment samples collected by the Survey were routinely scanned with a scintillometer. There were no samples which were significantly above background. Because so little is known about the uranium content of rocks in the area, 65 rock and stream- sediment samples were selected for uranium analysis. These samples were selected B-192 primarily on the basis of containing 10 ppm molybdenum or more. This procedure was suggested by the strong geochemical association of molybdenum with uranium in a wide variety of deposits. Results of these analyses are given in table 10. TABLE B-10 NEAR HERE Rogers and Adams (1969), indicate most silicic igneous rocks con tain about 3 to 10 ppm uranium and Levinson (1974) gives an average crustal abundance of 2.7 ppm uranium. The maximum uranium value in any analyzed sample is about 6 ppm and the mean uranium content of the 65 samples is 1.7 ppm. The rocks thus rarely contain uranium values above the usual background level and the average content of uranium in the rocks is below the average crustal abundance. The area is apparently lacking in significant uranium mineralization but the data is sparse and small vein-type deposits in particular could have been overlooked. Correlation Studies Both the rock and stream-sediment analytical data were treated statistically to determine correlation coefficients for each pair of elements. Detailed results of this analysis are reported in Johnson (1978). Groups of elements which correlate well with each other were found both in the rock and stream-sediment studies. Table B-ll summarizes those associations with moderately high correlation. TABLE B-ll NEAR HERE B-193 Table P-lO.-- Results of uranium analyses of select*H Geoloqical Survey samples, Samole Latitude Longitude LI (ppm) Sample Latitude Longitude U (pom) ^** 66Af 061 58 39 12N 135 51 20W 1 .8 769J128A 58 40 57N 1 37 34 36W 0. 4 66AF143 58 40 28N 136 3? 52W 1 .0 76CN0540 S? 30 21N 136 58 1 3W 1 . 4 66CH170 53 52 35N 135 40 SOW 2 .4 76CND59C 58 3d 25N 137 26 26W 0. 6 66CH257 58 46 39N 136 18 06W 1 .0 76CN069A S8 33 13N 137 20 12W 1. 0 660B569 58 25 22N 136 30 2 3W 1 .0 76CNP.69U 58 33 13* 137 20 1 2W 0. 6 * 665B646 58 27 34N 136 31 4 1W 5 .8 76CN108 A 58 43 54N 137 25 41W 1 . 4 66EM274 58 50 19N 135 40 29W 6 .2 76CN108-9 58 43 54N 137 25 41W 1 . 0 66LH325 58 22 14N 136 17 01W 5 .4 76CN11 1 A 58 23 57 iv- 137 06 46W 1 . 8 A 66LH352 58 43 19N 135 58 27W 5 .0 76CN116C 58 39 15N 137 ?9 40W 1. 0 66LH368 59 02 36N 137 00 16W 5 .6 76CN124A 58 44 04N 137 40 32W 0. 4 * 759J095A 58 25 45M 135 31 06W 0 .4 76CN1249 58 44 04 N 137 40 32W 0. 4 753J108A 59 03 54N 135 48 43W 1 .4 76DB0488 58 20 03N 136 43 52W o. R 75BJ1P8B 50 03 54N 135 48 43W 1 .4 760B0523 58 18 50N 136 46 17W 1 . 8 IA 75CN107A 58 54 0?N 136 15 02W 1 .0 760P1379 58 32 16N 136 54 20W 1 . 8 75CW1078 58 54 0?N 136 15 02W 1 .0 76DB146A 58 26 27N 136 5? 17W 0. 4 * 75CN108A 58 54 01N 136 15 32W 2 .2 76D8185A 58 45 53N 137 43 57W 1 . A to 75CN115A 58 47 07W 136 49 OOW * 75CN128A 59 00 SON 135 53 07W 0 .8 76DG066B 58 46 16N 137 44 OOW 2. 4 75CN128B 59 00 SON 135 53 07W 1 .4 77BJ050G 59 06 26N 136 50 29W 1 . 4 75CN143A 58 20 02N 136 48 12W 2 .0 77BJP50H 59 06 26N 136 50 29W 1 . 4 tt 750B134A 5« 31 59N 135 28 22W 1 .4 77PM032C 53 39 5U1 136 29 SOW 5. 0 750B134B 58 31 59N 135 28 2?W 1 .8 77RM0320 58 39 51 N 136 29 SOW 4. 4 % 750B299C 58 3? 1«N 136 31 1 2W 1 .4 75DB308B 58 38 47N 135 32 51W 1 .8 75DP'09B 58 41 151* 135 36 30W 1 .8 ^ 75DB311 A 58 40 35N 135 36 1 2W 2 .0 75DB??5A 58 29 54 N 135 33 38W 1 .2 ^ 750R325B 58 29 54 N 1 35 33 38W 1 .0 75DR??7A 58 32 3?N 135 36 03W 1 .0 75DB3?7B 58 3? 32N 135 36 03W 0 .8 %J* 75DB? 1!3A 58 51 37 N 137 06 01W 0 .4 75DB3?3B 58 51 37N 137 06 01W 0 .4 0 75KPP46A 58 32 OON 136 24 45W 2 .4 75KPP46B 5» 32 00 N 136 24 45W 5 .0 75KBP69B 58 22 33W 136 30 SOW 0 .8 u 76AF116B 58 30 0?W 1 37 12 28W 0 .2 76AF12EA 58 2" 4?N 137 20 55W 1 .2 Table B-ll Correlation groups from geochemical analysis of rocks and stream sediment samples. Elements . Average Correlation Coefficient ROCKS Fe, Mg, Mn, Sc, Ti, V 0.56 Co, Cr, Cu, Ni, Sc, V .50 Ba, La, Sr, Zn, Zr .32 Ca, Mg, Mn, Sc, V .50 STREAM SEDIMENTS B,. Cu, Ni, Pb, Zn .46 Co, Cu, Fe, Mg, Ni, Sc, Ti, V, Y .49 Co, Cr, Cu, Ni ' .59 Ba, La, Sr, Zr ,.46 B-195 Groups of elements with high correlation may be related to the usual geochemical relationships in rocks, or they may be related to mineral ization. To examine the spatial distribution of these groups, the elements in each group were combined to give a composite group level and plotted as the single elements had been (Johnson, 1978). These plots were then used to better define the location of geochemically anomalous areas (figures B-20 and B-21). B-196 9-1267 Mineral resources by Arthur L. Kimball, Jan C. ^till and Jeanne L. Rataj Introduction Present studies 5 The present Bureau of Mines study of Glacier Bay embraces pre- field, field and post-field activity constituting research of known data/ on-site collection of new data, and synthesis of both into a public report. The pre-field stage consisted of claim records and literature i j 10 search; contact with exploration companies, consultants and prospectors^ i cooperative work with the U.S. Geological Survey regarding local and j i regional geology; and identification of geochemically anomalous areas. ii 13 The information thus obtained on deposits, prospects/ claims/ anomalous ! i i areas and stained zones was synthesized to identify important £i«JLd i i target areas. Some tentatively important target areas were not j identified until after the. field work was completed due to circumstances i beyond our control. ! During Bureau field studies on-site examinations of prospects, . mines/ workings/ stained zones and geochemically anomalous localities were made. Also/ geological and engineering mapping/ and quantitative 21 sampling was done at some sites in detail. Claims which could be found i were examined. Several prospects noted in literature were not founsi. : i Eighteen person-months during July and August of 1975, 1976 and ! 1977, and October 1977, were spent conducting field studies. About 25 50 percent of this work was based on the USGS research vessel "Don .'i.': io >.:' .; -: *-'*r-3 C-l 9-1267 J. Miller," and about 35 percent from the charter motor vessel "Blue Star." This work was helicopter-supported whereas most of the remaining 15 percent, largely conducted from tent camps, was not. Bureau field investigations were conducted by Art Kimball, Jan Still, Jeanne Rataj, 5_ Mary Ann Parke, Al Clough, Mike Affleck and Sue Arthur. i Search for reported prospects and claims was made by helicopter, | i 7 | small power skiff, and on foot the latter particularly in precipitous i I i or timbered areas. i Many areas visited by the Geological Survey in 1966 (MacKevett 10 and others, 1971) were revisited in the field by the Bureau of Mines during the present study to confirm aspects of available information, j i to sample in greater detail, or to gain other information about a 13 particular mineralized site or area. Most of the 1966 data are given 14 directly or synopsized in the present study report. i5_ | One area of examination entirely outside the scope of the 1966 ! 16 ; study was reconnaissance of 60 miles of Pacific beach sands. Bureau T/ ; reconnaissance was conducted primarily on the modern beach. Extensive i i 8 | back beach exists, virtually all of which is heavily timbered. Were -9 ; detailed sampling to have been considered and properly done to gain* i 20 i depth information in the areas of back beach as well as modern 21 i beach,, extensive use of heavy equipment would have been required. j ?2 | This would not have been allowed by the National Park Service or the i 23 | financial resources which backed this project. 24 Post field work by the Bureau consisted of synthesizing pre- field information with that generated during the field study/ and included preparation of this report text and its engineering back up data into its final form. Mineral deposits were partially evaluated in some instances where it was prudent to make resource calculations (i.e., where there was enough information to allow sound estimates). For some deposits, resources by tonnage and grade have also been expressed in dollars, always as a simple dollar value per avoir^dupois pound or troy ounce of metal times the number of pounds or ounces of metal indicated or inferred in the reserve estimate. Such dollar amounts are here referred to as "gross in place metal value," and are used as comparative size figures only, and do not imply economic viability or the lack of it. The following values for metals have been used in these calcula tions (all except gold are February 1978 Engineering and Mining Journal prices: copper $ 0.63 per pound lead $ 0.33 per pound zinc $ 0.31 per pound silver $ 4.93 per troy ounce platinum $188.00 per troy ounce nickel $ 2.08 per pound molybdenum $ 4.31 per pound tungsten tri- $140.00 per STU (short ton unit) oxide Gold has been rounded to $150 per troy ounce so as to be easily convertible to any desired value in a highly fluctuating price. Sampling Sample types About 930 representative rock samples were obtained from veins, mineralized zones, mineral-stained areas and anomalous sample sites on the surface, in open cuts and in underground workings examined. . C-3 Representative samples were of four types: (1) channel sample moiled across a measured width; (2) chip sample uniform-sized chips taken continually along a measured line; (3) spaced-chip sample chip samples taken at uniform intervals along a measure line; and (4) composite grab sample random fragment composite from a small estimated or measured area. Grab samples composed of single rock fragments, usually float, were sometimes collected as well. Petrographic specimens were obtained from many of the sample sites to establish rock type and mineralogy. About 190 stream sediment samples were taken to serve as geochemical indicators at or near specif ic sites for back-up or verification of previously obtained anomalous samples. About 400 beach sand samples were obtained with auger or drive tube from holes of measured depth for quantitative determination of specific valuable heavy minerals present. Sample tables and analyses Samples were analyzed by the Geological Survey, who ran a standard 30-element semiquantitative spectrographic analysis (spec in tables) on each as well as four elements by atomic absorption (AA) (i.e., copper, lead, zinc and gold). Some samples had special analyses run for elements such as tungsten and platinum group metals at the Bureau of Mines laboratory in Reno, Nevada. Other samples were submitted to a private laboratory for atomic absorption molybdenum determinations. Many samples were fire-assayed for gold by the Bureau of Mines laboratory in Juneau, Alaska. Results Of USGS analyses of USBM C-4 samples are available through National Technical Information Service (NTIS) (Forn and others, 1978). Tables of analytical results which accompany individual prospect descriptions in the text report sample values for the elements con sidered important for the particular type of deposit sampled. The letter "L" used in reporting sample analysis means that the element was detected but was below the limit of quantitative determination. The letter "N" indicates that the element was looked for but was not detected. A rough lower limit of quantitative measurability of 14 of the analyses more important metals sought in spectrographic and atomic absorption/ is given in figures B-7 through B-19 chapter "B." Since in addition to spectrographic and atomic absorption analyses a number of samples were analyzed / for gold and silver by fire assay/ the applicable lower limits of quantitative measurability by this method with a one assay ton sample are given here as 0.15 ppm for gold and <0. 15 ppm for silver; however in some instances about half of these amounts can be estimated on a reas onable basis. Spectrographic analyses required 10 milligrams of sample while atomic absorption required 10 grams. Fire assay used an assay-ton or nearly 30 grams of sample and is considered the most reliable of the three methods for gold and silver assays. Measurement Veins and sample widths and other field measurements were made in English units. English units have been retained in the "Mineral Resources" section of the text. Both English and metric units are given in analytical tables. Since measurements were in English units, C-5 9-1267 to use the metric equivalent alone would imply either a greater or lesser precision than that of the original measurement. Production All recorded production from the monument is from lode and \ i i 5 :placer gold deposits. : ! I ! i t 1 Except for a small shipment from Sandy Cove lode gold production 'I i < 7 j reportedly all came from the Reid Inlet area, although information on ' I ! | i 8 j the amount of gold recovered from individual mines is either lacking i 9 jor incomplete. According to Rossman (19590/ between 1938 and 1950 at i 10 ileast 2,500 tons of ore with a recovery of about $100 per ton was H j mined in the area. A small amount of lode gold may have been mined i 12 jprior to that time and also since then. Most placer production probably came from the Pacific beaches not far north, and south, of Lituya Bay. It is estimated that about $75,000 (Mertie, 1933) was recovered from beach placer deposits on the i i i Pacific shore of the monument between 1894 and 1917, the time of i I Mertie 1 s visit. According to Mertie (1933), a report of one clean-up i of about two cubic yards of concentrates yielded about an ounce of ' gold and 0.15 ounce platinum. There are, however, no records that | platinum was produced and none was detected in Bureau reconnaissance i | samples of the beach sands. . | - | Placer production records are not complete > for although recorded i! ' ! production appears to have begun in 1894, some unknown amount of mining preceded that date. Also, there is no record of how much production has i occurred since 1917, the date of J. B. Mertie's visit, although some C-6 9-1267 1 | reportedly has. ii 2 { Placer claims have been located since 1963 in the Dundas River 3 drainage. Mining equipment has been taken into the area; however, | 4 I it is not known whether any production-occurred. i 5 ; Small quantities of placer gold are also reported to have been i 6 iproduced in the Reid Inlet area (Rossman, 1959) and from the outwash j / ! of Brady Glacier (Rossman, 1963b). i 8 i Mining claims i 9 i A search was made of the claim records of the Juneau Recording 10 ; District whose records date back to 1880. Certificates of location and any affidavits of annual assessment work for all recorded claims i in the study area were examined. About 1/200 claims have been located i j | 13 : in the area with the earliest of these recorded in 1885. Eighty i i s | percent of these were lode claims. Of the approximately 210 placer j 15 '.claims filed, 190 were located on beach deposits in the Lituya province^ j ! 16 i A coal claim located about 10 miles northwest of Lituya Bay was I i i recorded in 1898. One marble claim was filed in 1896, probably covering j I 18 !a deposit in the Sandy Cove area. i | The Mining in the Parks Act of September 28, 1976 included the l i requirement that all active unpatented claims within the boundaries of ; i the monument shall be recorded with the Secretary of the Interior '' within one year after the effective date of that Act, or they would ; 23 automatically become void. Six parties recorded claims with the ., i [Secretary of Interior by the appointed date, according to Bruce 25 j Paige, National Park Service (oral communication, 1978). ! C-7 V-J267 jAll together, about 205 claims consisting of 143 placer claims, 57 lode 1 ! 2 iclaims, four tunnel sites and one mill site were recorded. Portions of 2 | the beach deposits between the northern edge of LaPerouse Glacier and i . i 4 !Cape Fairweather are covered by active placer claims. Gold Reserve i <_ Mining Co. holds a total of 136 claims grouped in seven blocks, three of s I which are continguous. The two Valley of Tears placer claims are 7 located on the Dundas River in the South Chilkat subprovince. In the 3 ,Reid Inlet gold area, active holdings consist of four tunnel sites, the 9 i six Joe's Dream lode claims, the two Challenger lode claims, the LeRoy :o- 'group of two lode claims and a mill site, and the five Mt. Parker Mining ' i |placer claims. The Nunatak molybdenum deposit in Muir Inlet is covered ' 12 iby the Nuna group of 35 claims. Prospects south of the head of Geikie ! I u Inlet are included in the Woodlake group of eight lode claims and the i 14 Glacier nickel group of four lode claims. ;j-; Twenty-three patented lode claims are located within the study 1.5 area. Patent was obtained in 1965 by Fremont Mining Co. for the :* Nunatak group of 20 claims located on the Brady Glacier nickel-copper s deposit. These claims are currently under long-term lease to Cities Service Mineral Corporation, Newmont Exploration Limited, and Union 2:- Pacific Mining Corporation for possible development of the deposit. : The Silver Dick and Little Jennie claims staked on a silver prospect 2: 'in Rendu Inlet were patented in 1895. Ownership of these claims was i r. obtained by the National Park Service. In 1925, the Alaska Chief i :» claim was patented. This claim is located about two miles northwest of :c the mouth of Glacier Bay and is presently owned by the Nature Conservancy League. There are no patented placer claims in-the area-. C-8 The courthouse records show more claims than the number that were actually found in the field. About 25 percent of the claims filed were restakes of formerly located prospects. Assessment work was recorded for about 770 claims. About 210 claims had assessment work filed for two years and 310 claims had assessment work filed for three years. Descrip tion of the locations of some claims was given as a certain bearing and distance from the face of the glacier. An effort was made to construct a historical glacial front map for the area, but the location of many of these claims remained in doubt. Claim locations sometime?referenced a mountain or bay with a local name that has not been preserved. Monuments or possible workings on the old claims may have been obliterated. The distribution of claims within the monument is shown on plate III, where claims have been grouped and r in some cases, locations are generalized. Areas favorable for mineral deposits Molybdenum and porphyry-copper, magmatic nickel-copper-platinum, volcanogenic zinc-copper-silver-gold sulfide, stratabound zinc-copper, contact tungsten-copper-silver, vein lode gold, and ilmenite-gold beach placer deposits occur within the monument. As discussed in detail in chapter D, there are six areas believed to have higher mineral potential than elsewhere in the monument. These areas are identified in figures A-l and C-2 and tables A-l and C-l. Areas favorable for mineral deposits are outlined on the basis of C-9 (p. C-12 follows) Table C-1. Important mineral deposits and favorable area; in Glacier Bay National Monument Wilderness Study Area Favorable area Estimated (sec Chapter D; Significant Difficulty of amount pf / location shown Known occurrences with significant iden prospects or mineral explora past mineral on fig. C-2) tified resources anomalous areas tion exploration Economic geology and comments A. Crillor.-LaPerouse Brady Glacier Ni-Cu. Diamond drilling Numerous showings Difficult. Rugged Very little Layered mafic stock is an environ stock and vicinity has established 90-100 million tons of of Cu, Hi, Ti and high mountain gla ment for Ni, Cu, Pt, Pe and Cr area 0.534 Ni and 0.33% Cu for an in place Pe mineralization cial terrain, ex magmatic segregation-type deposits. gross value of About $2.5 billion with occur in the wes cellent rock expo present economic potential. Unspec tern and northern sures in places. ified by-product platinum group matals. portions of the Inferred tonnage should be equal to indi area 9 cated for a total value of $5 billion. B. Margeria Glacier Orange Point volcanogenic 2n-Cu (open to Two additional Moderate to diffi- Very little Area consists of marine volcanic area the north and at depth). Based on sur showings of poton- cult. Rugged fiord and sedimentary section intruded face sampling, there are 270,000 inferred tial volcanogenic and high mountain by granitics. An environment for tons at 2.7% Cu and 5.2% Zn, and 530,000 2n-Cu nuneraliza- glacial terrain, volcanogenic Zn-Cu deposits and inferred tons at 0.4% Cu and 0.3% Zn with tion, important excellent rock expo- porphyry-type Cu-Mo deposits. by-product silver and gold. Gross in Mo showings and suires in places, Lesser potential for contact place value of $20-$25 million with pres numerous addition or replacement-type Cu, 2n, W, Ag ent economic potential. al showings of Cu, deposits or vein-type Au, Ag, W, Zn, Au, Ag, and W Cu-Zn deposits. Margcrie Glacier Porphyry Copper (open to mineralization are the north <*r.d at depth) . Based on surface present. sampling, there are 160 million inferred tons at 0.24 Cu, 0.01% W, with by-product silver and gold. Gross in place value approximately $0.8 billion with future economic potential. C. Muir Inlet area Nur.atak Stockwork-typa Molybdenum (open to Numerous showings Moderate, Excellent Moderate Porphyritic granitic dikes and the north and at depth). Based on surface of Cu-Mo mineral- rock exposures plugs form east-west trends ay sampling and diamond drilling, chare are ization including moderate relief opposed co north-west trends in 145 million inferred tons at a grade of the iiruce Hills the remainder of the monument. from 0.044-0.064 Mo and 0.02% Cu for an These intrude metamorphosed approximate gross in-place value of $0.5 sediments. An environment for billion with future economic potential. porphyry or stockwork-type Mo-Cu deposits. Lesser potential for vein-type Cu, Mo, Ag, W deposits or replacement or contact-type Cu-Zn-W deposits. Table C-l. Important mineral deposits and favorable areas in Glacier Bay National Monument Wilderness Study Area, cont'd. Favorable area Estimated (see Chapter D; Significant Difficulty of amount of location shown Known occurrences with significant iden prospects or mineral explora past mineral on fig. C-2) tified resources anomalous areas tion exploration Economic geology and comments 0. Rendu Glacier area Massive Chalcopyrite Skarn Occurrence. Float and in Difficult to very Almost none High-temperature, high-grade Very limited surface sampling indicates placd samples difficult; deposits skarn-type deposits containing an inferred 4/300 tons with an estimated indicate an area are amenable to W, Cu, Ag, Au and Zn -are located average grade of 0.52% tungsten, 5% of high tempera magnetometer-type near diorite-li^estone contacts. copper, 7 ounces silver per ton and 0.15 ture W, Cu, Ag, prospecting. ounces gold per ton for a v&liu.. of $215 Zn, and Au miner O per ton. alization extend- .1 ng intermittently for at lea'st 2>» miles. E. Raid Inlet Gold Mining in the 1940's from the surface Highland Chief, Easy to moderate Moderate to The gold deposits are found in thin Area and shallow underground workings resulted LeRoy Mine, high) much nonpersistent quartz veins or in '{-million dollars or more in gold . Rainbow Mine, early surface altered zones hosted in granitic being produced predominately from the Russell Island, prospecting. or less often metasedimentary LeRoy and Rainbow mines. and numerous rock. The gold values are spotty. other gold show While the potential for discovering ings including large important deposits is low, some placer the potential for finding additiond prospects. small deposits by underground exploration and detailed prospectiig is good. V. Pacific Beach A total of approximately 4,000 oz. Beech sands bear- Difficult, al- Moderate to Small near surface concentra- Sands of gold worth $75,000 was recovered ing ilmenite though modern high tions of heavy minerals from the beach sands deposits between and/or gold at beach accessible. widely distributed between 1890 and 1917 by small-scale mining various locali Back beach Sea Otter Creek and Boussole operations. ties between Sea heavily Bay. Sands unassessed in Otter Creek and vegetated. back beach, offshore, and at Boussole Bay. i depth. Table C-l near here known occurrences and on geology, geophysics, and geochemistry. The known occurrences have potential themselves and/or are indicators of an environment favorable for mineral deposits. Other areas with mineral potential not indicated may lie in parts of the monument covered with ice and snow. The six areas listed in table C-l and shown on figure C-2 contain a known gross in-place metal value of $6.4 billion in indicated and inferred mineral resources. They represent about 8 percent of the monument and probably contain almost all of the undiscovered resources. Commodity discussion The more abundant metals found in the monument are listed in table C-2 along with the parameters that identify their national Table C-2 near here importance. References are given at the end of the table. Deposits with large resources of copper, nickel or molybdenum are known in the study area. The primary uses of nickel and molybdenum are in making essential steel alloys while copper is the primary metal used in all types of electrical equipment. The United States exports molybdenum, while it imports 17 percent of the copper and 70 percent of the nickel it consumes. Silver, gold, platinum, zinc, tungsten and ilmenite are primary constituents of smaller deposits in the monument or secondary constituents of the larger deposits. More gold is consumed each year C-14 Table C-2--National importance of commodities found in Glacier Bay National Monument United States foreign de Most impor pendence (based Deposits tant are**; on import reli Commodity with signi or deposits ance as a percent in order ficant known with explora of apparent con abundance resources tion potential Main uses sumption) _ Copper Brady Glacier Bruce Hills Electrical Import 17v mostly Orange Pt. , Massive-chalco- equipment from Canada and Margerie copyrite , and f abri- Chile Glacier Tarr Inlet.. cation White Glacier, Dundas Bay al tered zone , Alaska Chief , Wachusett Inlet and numerous others Nickel Brady Crillon La- Stainless Imports 70% mostly Glacier Perouse stock, steel from Canada Fairweather stock Molybdenum Nunatak Bruce Hills < Alloying U.S. is an Molybdenum South side of element in exporter Johns Hopkins steel and Inlet anomalous cast irons Mo area , Threesome Mtn. , Wachusett Inlet & numerous showings or anomalous areas Gold Orange Pt., LeRoy and Rain- Jewelry, Imports 60% and Margerie bow Mines , art and consumes more in Glacier Russell Is- industrial industrial uses land , equipment than produced. Rambler > Imported mostly Highland Chie* from Canada and Pacific Beach South Africa sands* Massive Chal- copyrite and numerous others Zinc Orange Pt. White Glacier , Die Import 58% mostly Mt. Brack, casting, from Canada and Tarr Inlet knob galvani Mexico zing chemical processes Tungsten Massive Threesome Mtn., Cutting Import 38% mostly Chalcopyrite, Dundas Bay tools, from Canada and Margerie tungsten mining Bolivia Glacier prospect equipment C-15 Table C-2 National .importance of commod 11 ie." found in Glacier Ray National cont inued United States foreign de Most impor- pendence (based Deposits tant aro*=; on import reli Commodity with signi- or deposits ance as a percent in order ficant known with explora- of apparent con- ahnndance resources _ tion potential _Main uses sumption) _ Silver Orange Pt.. Massive- Photo- Import 42% mostly Margerie Chalcopyrite, graphy, from Canada and Glacier White Glacier. electro- Mexico Mt. Brack, plated Sandy Cove, ware, ele- Tarr Inlet knob, tronics Russell Island Titanium Pacific Astrolabe- Mostly Import 38% of beach De Langle used as ilmenite mostly sands stock, Crillon- pigment , from Canada and (ilmenite) LaPerouse stock, 5% areo- Australia. Fairweather space in Import titanium stock dustry mostly from Japan and USSR Platinum Brady Fairweather Catalyst Not mined group Glacier stock, in petro in U.S. (unspeci Pacific leum and By-product of fied by beach sands chemical copper re product) industry , fining, im pollution port most control of consumption on cars mostly from South Africa and USSR Chromium Fairweather High-grade Import 89% mostly stock, stainless from South Africa, Crillon-La- steel USSR and Rhodesia Perouse stock (favorable en vironment) Iron Astrolabe- Basic Import 33% mostly De Langle stock , from Canada and Queen Inlet Venezuela skarn , West of Rendu Inlet , East of Brady Glacier , Pacific beach sands , Crillon-La- Perouse Stock REFERENCES U.S. Bureau of Mines, 1978, Mineral commodity summaries - 1978 (with resource in formation by U.S. Geological Survey), 200 p. C-16 9-1257 in the electronics industry alone than is produced in the United States annually. About half of the silver and zinc consumed in this country is imported. Silver is critical in the photography industry and impor- 4 tant in electroplating and electronic components, while zinc is used i s_ ! for die casting, galvanizing, and in brass and chemical processes. The 6 I United States depends on imports of platinum mostly from South Africa 7 for almost all of its domestic consumption. Platinum is critical in the 8 | chemical and petroleum refining industries where it is used as a cata- ' : i p ; lyst. It is also used in automotive emission-control devices. The ! ! i 10 ! United States imports half its consumption of tungsten which is used inj i | i i n i cutting tools and mining and earth moving equipment. The United States ' i 12 ' imports most of the ilmenite or rutile it consumes; it is used mostly i , 3 i in paint and in small amounts in the aerospace industry. Areas in the i 14 | monument are favorable for the presence of chromium and iron deposits, J ,, i! and indications of such have been found. The United States imports 33 )6 | percent of its iron ore supplies, and almost all of its consumption of ,, j chromium. Chromite is critical in making high-grade stainless steel. i 13 i Organization Glacier Bay has been divided into five provinces on the 20_ I basis of regional geology. These divisions serve as a convenient ^ vehicle for organizing the report. To further facilitate report 20 ! organization, two of the provinces are subdivided making a total of ,3 i eight separate areal units, three provinces and five subprovinces. These are discussed in tha order given below which is substantially 017 133° Mu/'r Province 59° 9! Middle HI Geikie 00! Subpravince * Subprovince Base from U S Geological Survey, I: 1,000,000 S'tka, 1956 Figure C-2 Map showing the distribution of selected deposits and prospects EXPLANATION Boundaries Glacier Bay National Monument - International Geologic province Subprovince ( \ Area containing known mineral deposits and favorable x% ' for additional hypothetical resources as determined by the U-S. Bureau of Mines and U-S. Geological Survey in Chapter D. A. Grill on-La Perouse area B. Margerie Glacier area C Muir Inlet area D. Rendu Glacier area E. Reid Inlet area F. Pacific beach sands Selected deposits and prospects shown on map 1. Mt. Brack zinc-copper prospect 2. The Nunatak molybdenum deposit 3. Bruce Hills copper-molybdenum prospect 4. Wachusett Inlet copper-molybdenum prospect 5. Massive chalcopyrite deposit 6. Tarr Inlet knob prospect 7 Margerie Glacier porphyry-copper deposit & Russell island gold prospect 9. Orange Point zinc-copper deposit 10. LeRoy gold mine and Rainbow gold mine 11. Rambler (Challenger) gold prospect 12. Highland Chief (Joe's Dream) gold prospect 13. White Glacier zinc-copper prospect 14. Sandy Cove gold-copper prospect 15. Miller Peak copper prospect 16. Echo Creek gold placer prospect 17. North side of the South Crillon Glacier stained zone 18. South side of the North Crillon Glacier stained zone 19. Brady Glacier nickel - copper deposit 20. Threesome Mountain molybdenum - tungsten prospect 21. Alaska Chief copper prospect 22. Dundas Bay tungsten prospect 23. Boussole Bay ilmenite placer prospect 24. Dundas Bay altered zone C-19 9-1267 from west to east geographically: Lituya province, Fairweather pro vince, North Geikie sub-province, Middle Geikie sub-province, South Geikie sub-province, Muir province, North Chilkat sub-province, and South Chilkat sub-province (see plate III). -_ I The discussion of each province or sub-province begins with a i i brief introduction touching setting, broad geology, and the more i i important mineral occurrences. To- Mineralized localities not discussed in the text in detail are tabulated at the end of the discussion of the portion of the province or sub-province in which they occur. Tabulation includes name, , 3 ; commodity, description of location, deposit and sample descriptions, i i claims if any, and data source. All such localities are shown on 15 j plate III. i ! Figure C-2 is a map of Glacier Bay showing the distribution of 24 selected deposits, prospects, and mineral occurrences. Province and Figure C-2 near here | sub-province boundaries are shown in figures'-B-2, C-2, and on plate III. Table C-3 is a list of localities in the monument arranged ; Table C-3 near here 25 C-20 Table C-3 List of localities, Glacier Bay National Monument (Mineral occurrences with a plate III number are discussed only in the table cited with plate III as the only location map) Other occurrences Main not Plate Analytical Discussed conmo- discussed in III Figure results, in text, Name of occurrence dities text, table # # * table * page # Adams Inlet, entrance of Mo C-64 86 Adams Inlet Cu C-64 85 - Alaska Chief prospect V Cu,Ag,Au C-2 - C-353 Alaska Chief prospect, Zn C-67 98 C-45,C-54 southwest of A. F. Parker prospect Au C-44 C-234 Berg Creek Cr C-64 79 - Blackthorn Peak, west of Fe C-49 61 - Blue House Cove Pb,Zn,Ag C-46 52 - Boussole Bay ilmenite ilmenite C-29 C-21 C-28 placer prospect Brady Glacier, east of Fe,Cu C-49 63 - Brady Glacier, east of Au C-49 64 - lower Brady Glacier, lower Mo C-49 65 - Brady Glacier nickel-cOppei^i»Cu,Pt - - C-96 deposit; I/ Brady Glacier outwash Au C-29 22 C-l,C-2 Bruce Hills Cu.Mo C-l,C-2, C-54 C-295 - C-61,C-62, C-63 Cascade Glacier, south Cu C-29 19 - west of Carroll Glacier, upper C-39 37 - Casement Glacier, east of Cu C-64 84 - Casement Glacier, nunatak on Zn C-64 83 Casement Glacier, moraine Mo C-60 76 - Casement Glacier, moraine Cu C-64 82 - Charpentier Inlet Mo C-46 58 - Churchill claim - C-45 - C-24& Contact Nunatak Au C-46 56 ' - Crampon ice gully M,Au C-42 C-38 C-486 mineralized area Crillon Inlet, west side of Cu,Ni C-25 1 - - Curtis Hills Cu C-58 73 - DeLangle Mountain magnetite Fe C-35 - c -iiy prospect Desolation Glacier, north Ni,Cu C-29 17 side of C-21 Table C-3.--I.ist of localities, Glacier Bay National Monument, continued. Other occurrences Main not ' Plate Analytical Discussed commo- discussed in III Figure results in text Name of occurrence dities text, table * # # table # page # '- Desolation Valley C-29 18 - - Dundas Bay altered zone Cu C-2,C-73 C-65 C-354 Dundas Bay, east of Fe C-49 69 - - Dundas Bay, east side of Cu C-49 68 - - Dundas Bay, west of Au.Ag C-49 66 - - Dundas Bay prospect W C-2,C-57, C-48 C-257 C-58 Dundas Bay, west arm of, Cu,Ag,Co C-49 67 island Echo Creek placer prospect Au c-fcf^e c-ii.c-u5 C-28 Sxray copper prospect Cu C-74,C-75 C-66 C-358 Fall Creek Au C-25 3 - - Fixed rope ice gully Cu C-42 C-38 C-186 skarn showing Fourth of July Mountain Cu C-46 57 - - Francis Island CU C-67 94 - - Fern Harbor claims C-49 70 - Gable Mountain Cu,Ag,Mo ,W C-58 75 - - Galena prospect Au C-45 C-233 Geikie Inlet, chromite Cr C-49 59 - claims Geikie Inlet, south of, Mo C-49 60 - near Blackthorn Peak Geikie Inlet, north shore of Mo C-67 92 - Geikie Inlet, south of, Mo C-49 62 - molybdenum occurrence Gilbert Island W C-46 51 - - Gilbert Island, southwest CU,MO C-46 53 - end of CU,MO C-46 54 - - Helicopter Pilot's molybdenum Mo C-29 4 - Highland Chief (Joe's Dream) AU C-l,C-2, C-43 C-222 prospect C-45,C-52, C-53 Hopalong prospect Au C-45 C-236 Hugh Miller Inlet Zn C-46 55 - - Incas mine Au C-45, C-49 C-41 C-215 Idaho Ridge W,MO C-65 C-56 C-310 Johns Hopkins Inlet, north Zn,Ag C-39 45 - shore of* at the entrance Johns Hopkins Inlet, molyb Mo C-38 C-168 denum-anomalous area Johns Hopkins Inlet, north Cu C-37 28 - shore of C-22 Table C-3. List of localities. Glacier Bay National Monument, continued. Other occurrences Main not Plate Analytical Discussed commo- discussed in III Figure results, in text, Name of occurrence dities text, table f f * table f page » Johns Hopkins Inlet, north- Zn C-39 46 west shore of Johns Hopkins Inlet, north Au ' - C-38 C-168 side of, gold anomaly Johns Hopkins Inlet, south Cu,Ag C-37 29 - * side of Johns Hopkins Inlet, south CU,W, C-37 30 - ~ side of Ag,Sn Johns Hopkins Inlet, south Cu C-37 31 - side of Johns Hopkins Inlet, south Cu - C-38 C-147 side of Kashoto Glacier, east of Cu C-37 32 - - Kashoto Glacier, east of Cu C-37 33 - - Lamplugh Glacier, southwest Cu C-37 35 - * of Lamplugh Glacier, southwest Hi C-37 36 - of LeRoy mine Au,Ag C-l,C-2 C-40,C-41 C-199 C-45,C-46 C-42 C-47 Little Jennie patented Ag - ~ C-187 claim I/ Margerie Glacier porphyry CU,W, C-l,C-2 C-34,C-35 C-149 deposit Ag,Au C-39,C-4C Margerie Glacier, north of, C-39 39 - stained zone Margerie Glacier, south of, C-37 25 - " stained zone. Massive chalcopyrite W,Cu, C-l,C-2 38 C-180 deposit Ag,Au C-42,C-43 C-44 Massive chalcopyrite W,Cu, C-42 C-38 C-183 deposit. mineralization Ag,Au in the vicinity WcBride Glacier, west of Au C-60 77 - - Miller Peak prospect Cu C-2,C-72-- C-63 C-342 Minnesota Ridge Cu C-66 C-57 C-310 Monarch #1 and $2 mines Au C-45,C-50 C-41,C-42 C-217 C-51 - Mount Abdallah Ni C-39 40 - Mount Barnard nunatak Cu C-39 38 - C-3i9 Mount Brack Zn,Cu C-2,C-67 C-59 Pb,Au C-68 Mount cooper Zn C-37 34 - Mount Lookout, l-h miles Ti C-27 10 - * south of C-23 Table C-3. List of localities. Glacier Bay National Monument, continued. Other occurrences Main not . Plate Analytical Discussed comma- discussed in III Figure results, in text, Same of occurrence dities text, table » * # table # page » Mount Lookout, 3-% miles Ni 027 11 south of Mount Marchain-ville Ti 027 12 northwest of Mount Marchain.VT.lle Ti 027 13 northwest of Mount Marchainyille Ni,Cu 027 14 northwest of Mount Marchainville Ti,Cu 027 15 northwest of Mount Marchain.viJ.la 027 16 northwest of C-345 Mount Merriam area V Fe,Cu Mount Parker area Au C-237 Mount Wilbur, southwest of Co O27 Mount Wilbur, southwest of Ti 027 6 . Mount Young #1 Cu,Zn 064 80 ,. Au,Ag Mount Young #2 Cu,Au C-64 81 Ag Mudslide Creek - C-25 2 North Crillon Glacier, Cu,Ni C-2,C-32 C-26b C-106 south wall, of Pt North Crillon Glacier, Cu 027 moraine at a 2,000 ft. elevation North Crillon Glacier, Cu 027 moraine at an 800 ft. elevation North Marble Island Cu 067 39 North & South Marble Island Marble 067 39,90 Nunatak molybdenum prospect Mo,Cu O1,O2 C-50 to O274 O59,O60 053 Plate IV Orange Point deposit Zn,Cu Ol,C-2 031 to 0129 Ag,Au 036,037 033 Pacific beach sands ilmenite, C-3 to C-4 to C-28 Au C-30 024 Palma River copper stain Cu C-29 20 - - Parker nunatak, south end of Mo C-46 47 - " Ptarmigan Creek basin Au C-45 - C-242 Queen Inlet skarn Fe,Cu - - C-345 Rainbow oine Au 01,02, C-41,C-42 0206 r-d%r- C-24 Table C-3. List of localities. Glacier Bay National Monument, continued. Other occurrences Main not Plate Analytical Discussed commo- discussed in III Figure results, in text, Name of, occurrence dities text,, table '# # # table # page ft Red Mountain Zn C-58 72 - Raid Glacier, east of Cu C-46 48 - Reid Glacier, east of head of Au C-46 49 - Raid Glacier, east of head of Cu C-46 50 - Rendu Inlet, ridge wast of Mo C-39 42 - Rendu Inlet, west of Fe C-39 44 - Rendu Inlet, west of mouth of Cu C-39 43 - Riggs Glacier, west of C-60 78 - Russell Island prospect Au,Ag C-45,C-2 C-45 C-238 Sandy Cove prospect Au,Cu C-2.C-71 C-62 c-334 C-72 Sandy Cove marble prospect Marble C-64 88 - Sentinal mine Au C-45 C-41 c_221 Silver Dick patented claim I/ Ag ~ ~ C-167 Shag Cove Cu C-67 93 - South Crillon Glacier, Cu,Ni C-2,C-33 C-26a c-101 north wall of South Crillon Glacier, Cu C-27 9 - north wall of South Marble Island Cu C-67 90 - Storms Iron prospect Fe C-67 99 - Sunrise prospect Au C-45 - C-233 Tarr Inlet knob prospect Cu,Zn C-2,C-39 C-36 C-162 Pb,Ag C-41 Tarr Inlet, west of Cu C-37 26 - . Tarr Inlet, west shore of Cu C-37 23 - Tarr Inlet, west shore of Cu,Mo C-37 24 - Tarr Inlet, west side of Cu C-39 41 - Tidal Inlet, south of Cu C-64 87 - Threesome Mountain deposit Mo,W C-2,C-56 C-47 C-253 3,087 Nunatak I/ CU - - C-147 3,850 Nunatak CU C-37 27 - - Triangle Island Mo C-58 74 - Triangulation Station "Garnet " Cu C-29 21 - Valley of Tears placer I/ Au C-363 Van Horn Ridge Mo C-58 71 Wachusett Inlet prospect Cu,Mo C-2,C-64 C-55 C-307 Whirlaway claims AU c"45 - C-237 White Glacier mineralized Zn,Cu - C-2,C-69 C-61 areas Ag C-25 Table C-3. List of localities, Glacier Bay National Monument, continued. Other occurrences Main not Plate Analytical Discussed cosnno- discussed in III Figure results, in text, Name of occurrence . dities text, table ft ft ft Willoughby Island, marble Marble C-67 97 - prospect Willoughby Island, northeast Cu C-67 95 - side of Willoughby Island, northwest Ag C-67 96 - side of Wood Lake, gold placer Au - - - - C-264 south of I/ York Creek Cu C-67 91 - V Prospect discussed in text with plate III as a location map. C-26 alphabetically. It gives main commodities, plate III location numbers, figure and table numbers and the number of pages where discussed in the text. 027 9-1267 Lituya province The Lituya province is bounded on the west by the Gulf of Alaska with the Fairweather fault forming the eastern boundary. Deposits of ]unconsolidated detritus of the coastal plain are flanked by a succes- i |sion of emergent shorelines represented by terraces carved in the ii |Tertiary and Cretaceous metasedimentary and metavolcanic rocks that Iform the coastal foothills. Tertiary and/or Cretaceous acidic intru- i isives outcrop adjacent to the Fairweather fault from the head of Lituya Bay northward to the monument boundary. Active and back beach |deposits of the coastal plain are shown in plate III. The beaches i contain concentrations of heavy minerals, including gold and ilmenite. i 12 JThe most notable of these placer prospects, Echo Creek and Boussole Bay, are shown in figure C-2. ' Pacific beach sands i '5 I Introduction and summary i ; Active and back beach deposits of the 60-mile long coastal plain i i 'and the southern Fairweather province were reconnaissance sampled during the present investigation. In 26 sample lines at 20 localities, 241 holes were bored to a maximum depth of 32.5 feet. Vertical channel ,and grab samples were also collected at some localities. Figure C-3 Figure C-3 near here shows the area investigated and the sample line locations. A total of 403 beach sand samples were collected and analyzed for their gold C-28 99°00' I5««00' Base from U S ol Survey Mt Foirweother 250, OOO 1961 Figure C-3 Index map for Pacific beach sands, showing location of sample lines C-29 9-1267 i and iitmenite content. An inferred resource estimate was made for the 'one square mile area sampled to an average depth of 6.4 feet. These i I calculations show that there are 6 million cubic yards of material containing inferred resources of 120 thousand tons of ilmenite and 1,200 troy ounces of gold for a total value of about 85 cents per cubic yard. Sampling was adequate for estimates of ilmenite content but was not adequate for exacting calculations of gold content. However, sampling was adequate to state that there are no large tonnages of high-grade placer gold in the near-surface beach sands sampled. An additional seven square miles of beach sand deposits exist that were not sampled. No platinum was detected in any of the samples. History and production Heavy mineral concentrations occur in sections of the surficial deposits of the coastal plain from Icy Point to Sea Otter Creek at the northern boundary of the monument. Unconsolidated deposits also containing heavy mineral concentrations are found in the pocket beaches located between Astrolabe Peninsula and Icy Point. During the past 100 years, the deposits of the coastal plain were intermittently mined for « gold and platinum. The earliest scientific observations of Lituya Bay were made by members of the LaPerouse expedition. A detailed survey of the bay and surrounding coasts conducted during a six-week stay in 1785 resulted in the production of the first map of the area. It is reported that the Russians later discovered that the beach deposits near Lituya C-31 Bay contained gold and that mining was conducted there intermittently until 1867, when Alaska was purchased by the United States. In 1890 Americans began working the auriferous beach sands and the good profits realized by the miners attracted as many as 100 men to the scene. Yields of $5 to $10 per day were won from the sands by the early workers who used shovels and rockers with amalgamation plates to re cover the gold. Later, the dozen or so men engaged in individual mining operations there used Long Tom or sluiceboxes to concentrate the gold from the beach sands. Unusually frequent and severe storms in 1896 resulted in improved mining opportunities and 150 to 200 men worked the beaches that year. The Lituya Bay Gold Mining Company was organized in 1901 to conduct a large-scale beach mining operation. A plant and warehouse were constructed at the mouth of Echo Creek, four miles northwest of Lituya Bay. Production elevators were used to hoist the sand into sluice boxes and water for washing the sand was provided by long flumes tapping nearby streams. In 1903 this operation ceased to exist due to the limited occurrences of pay streaks at the plant locality and the difficulty in providing sufficient water for hydraulicking. When a U.S. Geological Survey party, headed by F. E. and C. W. Wright, visited the area in 1906. No mining was in progress and the plant was in ruins. Activity by individual miners resumed by 1915 when a dozen men were reported to be engaged in mining the beaches of the area. Another party which included Mertie arrived in 1917 and this limited mining had ceased, but some prospectors were exploring both the modern beaches and the C-32 9-1267 elevated beach deposits of the marine terraces (Mertie, 1933; Wright 2 j and Wright, 1937; Brooks, 1953). In 1952 Rossman made a cursory examination of the beach deposits between Sea Otter Creek and Dixon Harbor (Rossman, 1957). The U.S. ^_ Bureau of Mines conducted reconnaissance studies in 1957 and 1958 of i 6 ! beach deposits along the eastern Gulf of Alaska, including the beaches 7 between Sea Otter Creek and Icy Point (Thomas and Berryhill, 1962). 8 j Cook investigated the amount and types of heavy minerals present in a large bulk sample obtained from a beach between Eagle and Portage 10 Creeks (Cook, 1969). A total of about 4,000 troy ounces of gold worth $75,000 was re covered from the beach sand deposits between 1890 and 1917 (Mertie, 1933). Records indicate that mining occurred as late as 1933, but the additional amount of gold produced is not specified (Smith, 1934). 15 Platinum was also won from the beach sands but no records of the , 6 ; total amount produced are available. A sample obtained near Echo 17 Creek contained one troy ounce of gold and 0.15 troy ounce of i 13 i platinum in two cubic yards of beach material representing a surface i 19 concentration. Platinum was detected at Topsy Creek, and at two i :o_ I miles south of Topsy Creek an ounce of platinum was hand-picked from 2 , 40 troy ounces of gold (Mertie, 1933). The deposits were never :2 i mined for their contents of other heavy minerals such as magnetite, 23 i ilmenite or zircon. 25- I C-33 9-1267 Mining claims A total of 191 placer claims have been located since 1890 on I beach sand deposits of the coastal plain between the northern edge iI | of LaPerouse Glacier and Sea Otter Creek. Thirty-seven of these claims were restakes of formerly-held property. In 1978/ 136 placer i claims were active, each covering 20 acres. The first claims staked ; on the beach deposits were filed in 1897. In that year two associa- ! tion claims were filed and each covered 120 acres of the beach north of the Fairweather River. One year later/ claims were staked at the 10 mouth of Sea Otter Creek. Between 1890 and 1898, beach deposits between Lituya Bay and the Fairweather Glacier were covered by 21 12 contiguous claims. Sixty years lapsed before additional claims were 13 staked on the beach deposits. In 1958, a block of five claims were staked on the beaches near Steelhead Creek, but these claims were 15 held only briefly. Between 1966 and 1968, a total of 136 claims were J i j staked by the Gold Reserve Mining Co. and these claims were all ; i i ! actively held in 1978. Twelve claims cover the beach; rleoosits north of i i Steelhead Creek, 19 claims cover the beach north of the LaPerouse 1 ! Glacier and 105 claims arranged in three contiguous blocks include : i beach deposits between two and 10^ miles northwest of Lituya Bay. ! i I Additional claims were staked in 1974 near the Crillon and Dagelet ! i 22 ! Rivers, but these locations were not active in 1978. No claims have ' i ! 23 i been recorded on beach deposits in Boussole and Palma Bays. ; C-34 9-1267 Geologic setting Bedrock In the Lituya province, a Tertiary sequence of marine and minor non-marine clastic and volcanic rocks thcit include the Yakataga formation underlies the beach deposits south of Lituya Bay. The \ Tertiary strata rest unconformably on Cretaceous metasedimentary and metavolcanic rocks that flank the beaches north of Lituya Bay. i Between the head of the Lituya Bay and the northern edge of the monu- \ i\ ment, diorite and granodiorite intrusives of Tertiary and/or Greta- ] I 10- ceous age are exposed. In the Fairweather province, a predominately i hornblende schist and gneiss terrain has been intruded by stocks of i 12 layered pyroxene gabbro of unknown age. Tertiary and/or Cretaceous ; i 13 intrusives of quartz diorite and granodiorite occur between the , 14 stocks. | Unconsolidated deposits \ Detrital deposits largely of Holocene age within the Lituya pro vince were classified by Rossman (1957) and by Plaf3(er (1967) , \ i according to their lithologic character and origin. The deposit types comprise active and back beach deposits that are partially covered by vegetation, and alluvium and glacial deposits that are largely vegeta 21 tion-covered. The active and back beach deposits are usually separated 22 by a scarp up to 30 feet high. Grass-covered back beaches grade into 23 forest-covered beaches, with backshore terrace between them at some 24 C-35 9-1267 localities. Figures C-4 through C-7 show the distribution of these 3 Figures C-4 through C-7 near here 5_ | deposits in the area investigated and the locations of the samples 13 ! 22 25 C-36 fair \ line no. } . .-. _. (Sea Otter Cr)< line no. 2 IRWEAWER ALASKA GLACIER Cape Fairweather EXPLANATION Active beach deposits Back beach deposits partially covered by vegetation Boundary of unconsolidated Sample line location deposits from Rossman (195 7) and Plafker (1967) Base from U.S. Geological Survey, Mf. Fairweather quadrangle 1-250,000 1961 Figure C-4 Sea Otter Creek to Fairweather Glacier, sample line locations C-37 Line no. 3 Line no. 4 , Une no 6 ,. . (Justice Creek) o \ ('Foirweather River'ft vicinity) (2 miles south Line DO. ll u> Block no. 2 of Justice Cr> 00 Blockm i, no. 3 » Lines no. 9- (Echo Creek) \ OF ALASKA 8'°CK n°' 4 0 GULF \ miles ' "^ ' kilometers X 0 I 2 3 La Chaussee 3ase from U.S. Geological Survey, Mt. Foirweather quadrangle 1:250,000 1961 Spit Explanation Active beach deposits Alluvium Back beach deposits, partially covered by Glacial deposits vegetation Boundary of unconsolidated deposits, from Sample line location Rossman (1957) and Plafker (1967) Figure C-5 "Fairweather River" to Lituya Bay, sample line locations .' I Aooffi /> Klorth Y me h HOOO ~> v anmort* Cenotaph {Cenqfa O line noTRF (Between Harbor Point line no. 15 (Topsy Creek) me and Steelhead Creek) line no. 18 (One[One mile north Harbor line no. 17 f the Block no. 5 Block no. 6 (Oagelet River) (Dagelet River) °? Point \ LaPerouse Glj Block no. 7 Block GULF OF no. 8 O J miles EXPLANATION Boundary of unconsolidated de \ kilometers Active beach deposits Alluvium posits from Rossman (1957)and o Plafker (1967) Back beach deposits partial Glacial deposits Sample line location ly covered by vegetation Grab sample location Base from U.S. Geological Survey, Mt. Fairweather quadrangle 1^250,000 1961 Figure C-6 Lituya Bay to La Perouse Glacier, sample line locations Boussole Head Astrolabe *y* Peninsula o I EXPLANATION Active beach deposits Line no. 19 Line nos. 20-21 (Between La Perouse Glacier back beach deposits partially covered and Icy Point) by vegetation. Block no. 9 Alluvium Glacial deposits Boundary of unconsolidated deposits from from Rossman( 1957) and Plafker (1967) GULF OF ALASKA Sample line location B6K048 Grab sample location \ Base from u S. Geological Survey, Mt. Fairweother quadrangfe 1:250,000 1961 Figure C-7 La Perouse Glacier to Boussole Bay, sample line locations 9-1267 collected. The beach deposits cover an area of approximately eight j square miles, equally divided between active and back beaches. i I Near Sea Otter Creek a 500-foot wide active beach is backed by a j vegetation-covered beach up to 1,300 feet wide. Between the "Fair- j I ; weather River" and Lituya Bay, beach deposits occur continuously for , i nearly 14 miles. The active beach has an average width of 500 feet, l with a 1,000 foot wide back beach. South of Lituya Bay, beach < | I i deposits occur near Steelhead Creek and between Topsy Creek and the | i \ LaPerouse Glacier, interrupted by outcrops of the Yakataga formation. I i I The active beaches are from 500 to LOGO feet wide and a back beach is ' i ii i present only within two miles north of the LaPerouse Glacier. Active i i 12 i beach deposits occur south of the LaPerouse Glacier to the drainage : ; i i t , of Finger Glacier, averaging 1,000 feet in width. In the southern ! i i | Fairweather province between Icy Point and Boussole Head, pocket ! 15~ beaches occur at Kaknau Creek, Palma Bay and Boussole Bay. The ; i i 14 ! beaches are flanked by headlands composed of gabbro and hornblende : schist and gneiss. i Beach detritus includes material ranging from clay through small . boulders. The surface of the active beaches is composed of sand with . j scattered cobbles, with layers of clay and silt encountered at depth i i at some localities. Sand-sized material comprises the back beach ii i deposits, with a thin mantle of soil found in the forest-covered i sections. i ! Unconsolidated deposits also occur on elevated marine terraces | found at elevations up to 750 feet in the coastal foothills between C-41 . -,;-: :,. -: -, = = 9-1267 Sea Otter Creek and Icy Point. The thickness of the beach deposits is poorly known. At Echo Creek, sampling was conducted to a depth exceeding 30 feet, the effective limit of the sampling method. Reimnitz and Plafler (1976) estimate that the detritus on the highest marine terrace north of Lituya Bay are 50 to 100 feet thick and that the deposits on the terrace northeast of the LaPerouse Glacier are 10 feet thick. Heavy minerals , those with a specific gravity greater than 3.3, occurring in the beach deposits include augite, epidote, garnet, ilmenite, magnetite and olivine.- Table C-4 lists the heavy minerals Table C-4 near here 13 detected in select samples of beach sands. Light minerals, those i I with a specific gravity less than 3.3, include andesine, biotite, 15 i chlorite, hornblende, labradorite, oligoclase and quartz. i l Provenance.of heavy minerals ; The prevailing fine size of the gold found in the beach sands suggests that it is being reworked from the Yakataga marine tillite formation. Rossman (1957) cites as an additional source the hydro- thermally altered zone south of Lituya Bay. Reconnaissance geochemical sampling by the U.S. Geological Survey during this investigation 22 identified trace gold contents in rocks at Mt. Escures and southwest of Finger Glacier. The gabbroic stocks are indicated as source rocks for the ilmenite and magnetite, with some contribution from the C-42 ' <'--' - -- - <--° TABLE C-4. Pacific beach sands, petroqraphic examination, heavy mineral constituents of select samples - -Location r Three i and one- Mineral constituents, Sea Otter One-fourth half miles percent of heavy Creek near North of the mile Three miles Two miles south of mineral fraction triangulation "Fairweather Justice Echo south of south of Topsy south of Dagelet La Perouse Boussole (s.g. greater than 3.3) station "Fair C" River" Creek greek Echo Creek Harbor Point Creek Topsy Creek Rfver Glacier Bay Andalusite - 1.1 _ _ ,, _ Augite 48. 4l/ 47.4 20.6^ 67.1 56.7 68. S^ 16. 7*/ 54. B^ 55. li/ 32. l^/ 41.1 Cassiterite - .5 .3 - - - - Chalcopyrite - - - - .1 - - Cinnabar - - - tr - - - Diopside - - - .- - - .9 Epidote 4.8 13.3 4.8 1.5 1.6 6.8 2.5 2.6 3.4 1.4 1.3 Garnet 16.1 16.0 9.6 8.3 18.5 10.3 12.6 17.3 13.8 1.4 3.6 r> Goethite - - .1 - tr - - - w Hematite - .8^/ - .1 .2l tr tr - - Hypers thene - 8.0 40.6 tr 52.9 48.6 22.0 Ilmeriite 6.4 ' l.l^/ 8.9 8.4 10.0 5.1 9.2^ 17.3 20.7 4.3 15.1 Kyanite tr - - tr - tr - Leucoxene - - - - .1 - tr - Magnetite 3.2 2.1 1.4 1.4 2.0 .3 .8 1.4 .7 .4 .6 Olivine 16.1 1.6 11.0 9.9 7.6 3.4 4.2 5.8 5.5 11.8 15.1 I'yrite tr .1 - - - - Rutile tr - - tr tr - tr. - - Scheelite tr tr . - Sphene .7 .3 - .2 .1 tr .1 Scaurolite 4.8 8.0 2.7 3.0 3.6 5.1 - .6 .7 - .2 Zircon .2 tr tr .8 tr - Trace amounts, less than 0.1 percent lyWith hypers thene 2/With diopside ^W1th pyHte 4/With chlorite 9-1267 volcanic and conglomerate units of the coastal foothills. Intrusives, both basic and acidic, have produced a high-grade metamorphic terrain shedding minerals such as garnet, staurolite and epidote. 5 10 12 15 16 21 22 75 C-4'4 Concentrations of heavy minerals The coast in the area investigated is subjected to the full force of wind and waves generated over the Gulf of Alaska, with longshore drifting further modifying the detrital deposits. Marine forces that tend to concentrate the heavy minerals are erratic, producing scattered surface accumulations that are approximately elliptical in shape, with the long axis paralleling the shoreline. During periods of erosion, lighter sands are removed leaving a concentration of minerals heavier/in favorable areas located near the high-tide line, seaward of the crest of the beach berm and near the base of the backshore terrace. These heavy mineral concentrations will be preserved only if they are deposited beyond the normal reach of the waves or transported by winds to the back beach. Alternate cycles of deposition and erosion may bury the heavy mineral accumulations or remove them from the beach. Most of the past gold production was from beaches near Echo Creek, with some gold produced from beach deposits located south of Lituya Bay near Steelhead Creek, Topsy Creek and two miles south of Topsy Creek. In general, the gold grains recovered by the mining operations were very small. At Echo Creek, the largest gold particle recovered was worth eight cents (0.12 gram at $18.40 per troy ounce). Between Topsy Creek and two miles south, a gold grain worth 74 cents (or one gram in size) was recovered (Mertie, 1933). Gold was detected in 30 percent of the samples collected during the present investigation, with the best value obtained from a grab sample of a C-45 9-1267 surface heavy mineral accumulation found near the Dagelet River that assayed at $1.02 gold per cubic yard and 972.2 pounds of ilmenite per cubic yard- Sampling method 5 A total of 403 samples were collected from the beach sands. Samples were grouped in lines transecting the entire prism of the active beach, including the intertidal zone, and those portions of the back beach that were not covered with dense vegetation. An attempt was made to keep the sample hole spacing along the line at ; j 10 50 feet, but the character of the beach material at a particular j sample site often necessitated variance from this standard. In 26 ! 12 sample lines at 22 localities, 241 holes were bored with a total foot age of 1,058 feet. These 363 samples represent a measured volume of ; i subsurface beach material. In addition, four vertical channels were i 15 cut from the walls of hand-dug shallow pits. Backshore terraces pro vided exposures for 24 additional channels. Twelve grab samples were | 17 collected, including three samples from surface heavy mineral concen 18 trations . 19 Shallow depth holes were bored with a Shelby tube sampler. This 20 seamless steel tube has an outside diameter of 0.25 feet and a wall 21 thickness of 0.005 feet, with the bottom of the tube beveled to a 22 cutting edge. PVC tubing with an outside diameter of 0.24 feet and 23 a wall thickness of 0.02 feet was also used. Tube lengths of four to five feet were employed and the top of the tube was fitted with an 25- anvil to permit hammer drive. After the tube was driven, a small C-46 9-1267 amount of water was added to the core contents to fill the interstices i of the sampled material, allowing the creation of a partial vacuum when the tube was capped by a tight-fitting cork. With this method, the entire column of material in the tube was retrieved when the tube was pulled. The tube length used was the maximum possible for easy driving and retrieval. An attempt was made to continue a five- foot hole with a 10-foot length of tube, but this proved to be impracticable due to the extreme difficulty encountered in pulling the longer tube. Since the holes bored by this method had a 10 constant diameter, the in-place volume of the sample could be calcu lated directly. 12 A 0.25-foot diameter Iwan auger was used to bore holes up to 15 j 3 i feet in depth, with a sample interval of about five feet. Care was 4 exercised to keep the hole vertical as it progressed and the auger i 15 i was passed very slowly through the hole to prevent material from i 5 j being scraped from the sides of the hole. Nonetheless, the excessive i 7 l amount of sluffed material that collected in the bottom of the deeper 5 holes was the depth-limiting factor for this method. The loose or ? expanded volume of the total sample was measured, then the sample was split with a Jones splitter. The diameter of these uncased holes varied, so it was necessary to use an indirect method to determine the in-place volume of the sample. At most localities samples were 23 obtained by the auger method, a test hole was augered to a depth of four feet and the loose volume of the material was measured. The 25 test hole was then lined with thin clastic tubing and the capacity C-47 9-1267 of the hole was determined by adding water, giving the in-place volume of the sampled material. The expansion or swell factor, determined by this process, varied from 1.09 to 1.1.33 with a mean of 1.26. Holes up to 32.5 feet in depth were bored and sampled with a 0.17 foot outside diameter and two-foot long split tube sampler. The sample was collected at the bottom of a cleaned bore hole by the drive weight method. Portions of the retrieved sample that appeared to be washed were discarded. Recovery of material in the 1.7-foot 10 sample interval varied from none to 100 percent, with a mean value of 50 percent. Retrieval of sample in the first five feet of the 12 hole was particularly poor, thus another sampling method was used 13 j to bore a hole to that depth near the site of the split tube sampler i ' » j hole. 15 | The average in place density of the beach material at each I 16 i sample site was computed from data provided by samples obtained by i 17 i tube or auger methods. This figure was used to determine the in- 13 I place density for samples collected by the split tube sampler or i IP vertical channels, since these methods had poor volumetric control. i 13 Although grab samples do not represent a given in-place volume, a 21 volume was assigned to these samples for the purpose of calculating 22 amounts of contained metal values. 23 The character of the beach deposits at each particular site 24 determined the sampling method employed. In the coarse, wet sand i 25- found in the swash zones of the beaches or in very fine, very coarse C-48 9-1267 or dry sand, the optimal method was sampling with a drive tube, PVC or Shelby. No difficulty was experienced in sampling below the water table. For moist, semi-compacted sand and pebbles, shallow holes could be successfully augered. The auger was used whenever these conditions prevailed, since this method allowed the sampler to record the thickness and depth of any layers of heavy minerals found in the hole. When the beach surface was covered with large cobbles, grab samples or channel samples of the walls of shallow hand-dug pits were collected. Exposures provided by the face of backshore 10 terraces were sampled whenever encountered. Limited split tube sampling was conducted at Boussole Bay and the mouth of Echo Creek. 12 Sample preparation and analysis | The beach sand samples were prepared and analyzed at the Bureau I 14 of Mines laboratory in Juneau, Alaska. First, a test group of 14 15 samples were analyzed petrographically. These samples contained from 0.04 percent to 15.5 percent ilmenite that was confined to the minus 20 mesh portion of the samples. Of the 14 samples, 11 13 contained gold ranging from trace amounts up to 0.005 troy ounces per ton. The gold occurs as thin flakes ranging from 0.2 to 0.07 millimeters in diameter. Based on these findings, an analytical 21 procedure was established to determine the gold and ilmenite content of the entire group of samples. Figure C-8 is a flow chart 23 ' 24 Figure C-8 near here -49 Platinum Platinum not indicated; indicated by end of frosted bead analysis Reject * saved Platinum content determined spectrogrophicailyj end of analysis Figure C-8 Flowchart for physical and chemical analysis of beach sand samples ~C-50 9-1267 detailing the process of the physical and chemical analyses of the samples. A 30-gram split of the minus 20 mesh portion of the sample was used to estimate the abundance of ilmenite of the entire sample. 5 Magnetite was separated from the split using a low-intensity perma nent hand magnet. Any remaining magnetite was concentrated from the split with a Franz isodynamic magnetic separator with a current strength of 0.15 amps. The tails from this separation were treated with the Franz instrument with a current strength of 0.36 amps, Id- removing as tails quartz and other minerals with a lower magnetic susceptability than that of ilmenite. Since large quantities of rock- forming minerals with optical properties similar to that of ilmenite 13 j were likely to be present in this concentrate, methylene iodide, rather than bronoform, was the heavy liquid used to sink the ilmenite-bearing fraction. The abundance of ilmenite in the concen- j 16 trate was estimated by grain count. This method was a lower limit j of determination of approximately 0.05 percent. A sample that j contained a trace but nonquantifiable amount of ilmenite was ! 19 designated as "L." No detectable ilmenite in a sample is signified | by "N." Ilmenite content is reported to the nearest 0.1 percent for j 21 the majority of the samples. In addition, a 30-gram split of the j j 22 10 by 20 mesh portion of the sample and the entire plus 10 mesh ; 23 fraction were visually inspected for ilmenite, but none was found j in any of the samples. i 25 9-1267 For determination of the gold content, the rejected fractions of the various separations performed to concentrate the ilmenite were recombined with the remainder of the sample. The plus 20 and minus 20 i! mesh fractions were panned separately and the combined concentrate of i less than one assay ton was fire assayed. The result of this analysis; | gives the upper limit of the total gold in the sample. The lower ; limit of detection by fire assay for a one assay ton sample is 0.002 milligrams gold. If gold was detected visually during the panning process but fire assay of the concentrate yielded a determination of ; 10 nil, a gold content of "L" was assigned to the sample. Samples with no detectable gold were designated "N." Platinum content is signaled by a frosted bead in the fire assay process and the effective lower 13 limit of detection is 0.032 milligrams of platinum in a 2.00 milligram 14 silver bead (Bugbee, 1940). No platinum was detected in any of the samples. Since the lower limits of determination of gold and detection of platinum varies with the sample size, the parts per million conversions of these limits for the various sample types are as follow: 052 9-1267 1 Lower limits of fire Average assay analysis , ppm > weight, Determination of Detection of Sample type grams gold content platinum 3 Shelby tube 5040 0.0004 0.006 .\ PVC tube 3560 .0006 .009 Auger 4300 .0005 .007 5 Split tube sampler 680 .003 .05 6 Vertical channel 3760 .0005 .009 7 Grab 4195 .0005 .008 Ilmenite concentrates were prepared from composite samples repre senting most of the localities sampled. These concentrates were JO- processed in an identical manner to the other beach sand samples, with the additional step of hand-sorting the ilmenite grains after the sample was prepared for the grain count. The U.S. Bureau of Mines laboratory in Reno, Nevada, analyzed the concentrates chemically for their titania content and provided 40-element semiquantitative spectrographic analysis. The results of these analyses are given in table C-5. ! Table C-5 near here ' Sample results | The average hole spacing within a sample line was 50 feet and | | the size of the sample collected ranged from 200 grams to 17,000 | grams, with an average of 3,500 grams. Effective sampling of a gold 1 placer prospect requires that a much larger sample be collected with a i i______c_5__. ______, Table C-5.--Assay data, Pacific beach sands, chemical and sem1quant1tat1ve spectrographlc analyses of llmenlte concentrates Chemical Semi quantitative spectrographic analysis.percent WWIIIfW*) I l*\S 1 V « I f_ t Location of samples percentl Al Ba Be Ca Cr Mg Mn Sc SI V Zr Sea Otter Creek near triangulation B6K169.180 50.5 0.7 0 .003 0.0006 0.6 0.2 0.6 62.0 0.003 2.0 0.3 0.01 o station "Fair C" I Sea Otter Creek near trlangulation B6K152.155A 48.9 .8 .003 .0006 1.0 .07 .7 62.0 .003 3.0 .3 .01 station "Fair B" Mouth of "Fairweather River" B6K147.148A 50.6 .6 N( .002) .0005 .5 .04 .6 62. 0 .002 2.0 .2 N(0.006) One mile south of the "Fairweather B6K138.139 53.5 .3 .003 .0006 N(0.2) .07 .6 62.0 .003 .6 .3 .008 River" Two miles south of the "Fairweather B6K131A.137 51.0 .4 .002 .0005 .4 .06 .5 62.0 .003 1.0 .2 .008 River" Justice Creek B6K079B ,085 55.3 .2 .003 .0005 NiO.l) .04 .6 .9 .002 .7 .3 N(0.004) Two miles south of Justice Creek B6K087C.089C 53.6 .2 .003 .0006 NlO.09) .05 .8 .8 .003 .6 .3 .007' Echo Creek B6K119A.122 53.5 .3 .002 .0006 Ni 0.07) .04 .7 .8 .003 .8 .3 N(0.004) One-fourth mile south of Echo B6K1 04,1078 54.0. .2 .002 .0005 NiO.09) .03 .7 .8 .002 .4 .3 N(0.004) Creek, prospect workings Three miles south of Harbor Point B6K197.199 53.8 .1 .002 ,0005 N{0.05) .03 .7 .7 .002 .4 .2 N(0.005) Topsy Creek B6K200.207 53.4 .2 .002 .0006 N(0.05) .02 .7 .7 .002 .6 .3 .006 Two miles south of Topsy Creek B6K214.215 52.1 .2 .002 .0005 N(0.05) .02 .8 .7 .002 .6 .2 N(0.004) Dagelet River B6K186.187, 55.3 N(0.05). .003 .0006 N(O.l) .02 .6 .8 .003 .2 .3 N (0.006) 191 Three and one-half miles south B6K068.071 53.6 .2 .002 .0006 N(0.05) .1 .6 .8 .004 .4 .4 .008 of La Perouse 61acier Kaknau Creek B6K051 ,063 54.4 .07 .003 .0005 N(O.l) .03 .6 .8 .003 .3 .3 N(0.004) Pal ma Bay B6K036.050 53.8 .09 .002 .0005 NfO.l) .01 .5 .8 .002 .3 .2 .006 Boussole Bay B6K001B.016 54.5 .1 .002 .0003 N(0.07) .02 .4 .8 .002 .3 .2 .008 9-1267 i j shorter hole spacing within the sample line. Constraints imposed by i! the limited time and equipment available for this investigation pre cluded an adequate program of sampling to insure that the material 5 10 12 13 14 19 21 C-55 9-1267 collected represented the true gold content of the beach deposits. The samples obtained were sufficient to adequately assess the ilmenite content of the sands, and to state that the bulk of the sands are extremely low in contained gold. Since fire assay analysis was used to determine the gold content of the samples, some of the values reported could be due to chemically combined gold. However, some free gold was detected during panning in most of the samples with a reported gold content by fire assay. Sample locations are shown in figures C-9 through C-29 with assay results given in tables C-6 10 through C-21. Figures C-9 through C-29 and tables C-6 through C-21 near here 13 Table 22 gives the weighted average grade of gold and ilmenite 15 Table C-22 near here 14 17 I across the lines of samples collected. Grab samples not representing 13 the tenor of the beach at a given sample line location were excluded from the grade calculation. At most of the sample line locations gold values were obtained; however, only scattered samples from the active beach contained gold, with more consistent values found in 22 the back beaches. Gold values were obtained from 11 out of 14 samples representing 24 a measured volume of the active and back beach deposits about 25 056 activt beach 60'- .approximate upper limit of ne*iea ! swash zone at law tide B6KI68 B6KI6S)I 40' 20'- active beoch< grass covered back beach B6KI72 B6KI73 B6KI74 B6KI75 B6KI76 B6KI77 B6KI78 B6KI79 - 60' - 40' - 3O' sea level -Iff Explanation B6K17I Augtr or PVC tubt o 20 40 eo sample location I i I i I i I »«t I I I I I « * ' 0 5 10 15 20 Assay data given in tabl« C-6 Mapped by A. Kimboll and J. Rataj , July 1976 Figure C-9 Profile of beach at Sea Otter Creek near triangulation station "Fair C" sample locations, line no. I approximate upper limit of swash zone at high tide 60' 60 40' 40' 20' 20' Seo Sea , Level garnet layer no layering- Level exposed -201 -20' EXPLANATION 0 10 30 50 70 B6K09I Agger or PVC feet meters I - tube sample 0 5 10 15 20 location A»say data given in tabloC-7 Mopped by J Rotaj ond A Clough, Jjly 1976 Figure C-IO Profile of beach at Sea Otter Creek near triangulation station "Fair B" sample locations, line no. 2 057 Table1 C-6 Assay data, Sea Otter Creek near triangulatlon station "Fair C", line number 1. i mien i u uuiu---- Sample Sample Hole In-place Pounds Dollars Troy 02. Troy 02. Cents 1 nterval , length depth , volume per per per per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd. I/ ton cu.yd. cu.yd.2/ Description B6K161 PVC tube 0.7 0.7 0.0008 0.3 29.4 0.81 L _ . Sand. B6K162 Do. 3.5 3.5 .0042 .5 14.5 .40 L - - Do. B6K163 Do. 4.3 4.3 .0052 .6 15.3 .42 L - - Sand and pebbles. B6K164 Do. 3.3 3.3 .0040 ' .6 16.6 .46 0.0003 0.0004 6.0 Sand and small cobbles. - . o B6K165 Do. . - 1.3 1.3 .0016 .4 8.9 .24 N Sand and cobbles. B6K166 Do. 2.45 2.45 .0030 .3 8.2 .23 L - - Do. Ul B6K167 Do. 1.7 1.7 .0021 5.6 . . Do. oo .2 .15 L B6K168 Do. 3.5 3.5 .0042 .4 11.5 .32 .0002 .0003 4.5 Do. B6K169 Do. 3.4 3.4 .0041 .6 17.1 .47 L - - Medium fine sand. B6K170 Do. 3.55 3.55 .0043 .8 23.8 .65 .0001 .0001 1.5 Fine sand and cobbles. B6K171 Do. 3.0 3.0 .0036 3.1 91.5 2.52 .0005 .0008 12.0 Do. B6K1 72A Do. 0.0-3.0 3.0 - .0036 1.8 51.9 1.43 .0003 .0004 6.0 Do. B6K172B Auger 3.0-5.3 2.3 - .0054 .4 11.4 .31 L ' - - Do. 5.3 B6K173 Do. - - 5.5 5.5 .0131 .9 29.1 .80 .0007 .0011 16.9 Fine sand. B6K174 Do. 5.5 5.5 .0131 .6 16.2 .45 N - - Do. B6K175 Do. 5.6 5.6 .0136 1.4 51.8 1.42 L - - Do. B6K176 Do. 5.4 5.4 .0126 1.6 54.0 1.49 N - - Do. B6K177 Do. 5.3 5.3 .0126 1.9 62.4 1.72 .0002 .0004 6.1 Do. B6K1 78 Do. 5.3 5.3 .0131 1.5 48.0 1.32 N - - Do. B6K179 Do. 4.3 4.3 .0099 2.2 72.8 2.00 N - - Clay, fine sand and cobbles B6K180 Do. 4.0 4.0 .0099 2.4 72.4 1.99 .00002 .00003 .5 Fine sand and cobbles. V Ilmenite at $55 per ton. Gold at $150 per troy ounce. Table e-7 Assay data, Sea Otter Creek near trlangulatlon station "Fair B", line number 2 i mien i ue Sample Sample Hole In-place Pounds Dollars Troy 02., Troy 02. Cents interval , length, depth, volume per per per* per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd.V ton cu.yd. cu.yd.2/ Description B6K150 PVC tube _ 2.5 2.5 0.0030 0.2 6.0 0.16 N _ _ Fine sand. B6K151 Do. .- 4.0 4.0 .0048 .3 7.7 .21 N - - Do. B6K152 Do. - 4.2 4.2 .0051 .2 5.4 .15 L - - Do. B6K153A Auger 0.0- 5.4 5.4 - .0129 1.3 36.2 1.00 L - - Fine sand and pebbles B6K153B Do. 5.4-10.0 4.6 - .0139 .8 24.7 .68 0.0001 0.0002 2.8 Do. 10.0 o 1 B6K1 54A Do. 0.0- 5.3 5.3 .0139 .9 27.2 .75 .0005 .0008 12.5 Do. U1 B6K154B Do. 5.3- 9.7 4.4 _ .0134 1.0 32.3 .89 N _ - Do. VO 9.7 B6K155A PVC tube 0.0- 3.8 3.8 - .0046 3.4 93.5 2.57 L - - Do. B6K155B Auger 3.8- 5.5 1.7 - .0053 1.3 36.2 1.00 .0003 .0005 7.3 Do. B6K155C Do. 5.5- 9.0 3.5 - .0113 .5 14.9 .41 N ,. . Do. 9.0 B6K156A Do. 0,0- 5.5 5.5 - .0134 1.3 34.8 .96 .0004 .0005 7.9 Do. B6K156B Do. 5.5- 8.9 3.4 - .0129 .2 6.3 .17 .0001 .0001 1.5 Do. 8.9 B6K157A Do. 0.0- 5.2 . 5.2 - .0150 .7 17.1 .47 .0002 .0003 3.9 Do. B6K157B Do. 5.2- 7.0 1.8 - .0150 .4 11.2 .31 L - - Do. 7.0 B6K158 Do. - 1.7 1.7 .0043 4.1 127.3 3.50 .0004 .0007 10.1 Do. B6K160 Do. - 4.0 4.0 .0088 1.0 28.3 .78 N - - Do. I/ Ilmenite at $55 per ton. 2/ Gold at $150 per troy ounce. active beach- forest - covered back beach approximate upper limit of zone at low tide 20' 20' B6KI40 B6KI4I 36KI48 - Sea Level -20' B6KI45 EXPLANATION B6KI53 Auger or PVC tube - r~"~~ sample location 0 10 30 50 feet i i .j. i i meters 5 10 15 Assay data given in "table C-8 Mapped 01 A. Clough and J Ro«aj, juiy Rgure C-ll Profile of beach north of the "Fairweather River" sample locations, line no. 3 grass- covered top of bockthore terrace -^ t Explanation ; ; : : r:;;:vl- Medium sand to fine 4 forest- covered back beach fr i;;:;:::,::;:;:!;;:,, pebbles mainly com- *-SS* __'"' " " " """ posed of felsic 30' 30' fliiii minerals, contains - - 1 occasional layers vertical ***^ pebbles. 20' - - 20' face of bockshore" terrace f.:.!.-ii:!.i.!.!.!-;.!.;.i.vi Coarse sand, mainly 10' see 10' xsmm lilili composed of garnet (igure B6KI39 I!!!!!! and other mafic to right ;. '- -'".-- '" " ' minerals. >^ Sea ^^JB6KI38 Sea " '"-" O 1 2 3 Level Level Y ! ? Y feet , 6 vz i meter -10' = / uppermost section of a total of- 4 feet of sluffed, 0 10 20 f . material - ' iii i feet Explanation 0 ' 2 4 6 meterS B6KI38 Auger "" "^ sample location Assay data given in table C-8 Mapped by A Claugh and J Rotaj , July !976 Figure C-12 Profile of beoch one mile south of fhe "Fairweather River", sample locations, line no. 4 C-60 active b«ach forest-covered back beach- approximate upper limit of 'swash zone at high tide 40 40 20' 20' B6KI35/ 86KI36I B6KI33 S«o B6KI34 garnet^ Sea Levtl layer Level -20' -20 EXPLANATION 86K132 Auger or PVC tube - r""""" sample location 0 10 20 feet 10 meters Assay data given in table C- 8 Mowed by J Rotaj end A dough, July |976 Figure C-13 Profile of beach two miles south of the "Fairweather River" sample locations, line no. 5 active beach gross-covered back beach approximate upper limit " "Of swash zone at low approximate upper limit of tide "swash zone at high tide 40' 40 B6K078 B6M380 S6K08I B6K083_ 20' a 085 B6K07K B6KO77 l___--_--7- B6K082 20 Sea Sea Level B6K084 Level -20' EXPLANATION 86K077 Auger or PVC tube _ -|-"~" sample location 010 30 50 70. . lit it > i I feet 0 5 10 15 ^0 meters A«toy data given in table C-9 Mapped by J Rataj and A. Clough, July 1976 Figure C-14 Profile of beach at Justice Creek, sample locationsjine no. 6 C-61 C~8--Assay data, "Falrweather River" and vicinity, line numbers 3,4 and 5. i imeiii ue- -uuiu- Sample Sample Hole In-place Pounds Dollars Troy oz. Troy oz Cents Interval , length, depth volume per per per per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd.jy ton cu -yd, cu.yd. 2J Description North of "Falrweather River ",Hne number 3 B6K140 PVC tube _ 3.0 3.0 0.0036 L _ _ L _ Coarse sand and gravel B6K1 41 Do. - 3.0 3.0 .0036 L - - N - Do. B6K142 Do. - 1.7 1.7 .0020 L - - L - Do. B6K143 Do. - 2.8 2.8 .0034 L - - N - Do. B6K144 Do. - .7 .7 .0008 L - - L - Do. B6K145 Do. - .8 .8 .0010 L - - N - Do. B6K146 Auger - 3.0 3.0 .0070 0.2 7.3 0.20 N - Do. * - B6K147 Do. 3.0 3.0"- .0087 .2 6.6 .18 L Do. B6K1 48A Do. . 0.0-4.8 4.8 11.9 .33 - Do. "_: .0101 .4 N B6K148B Do. 4.8-8.0 3.2 .0141 .4 13.1 .36 N - Do. 8.0 B6K149 PVC tube 2.0 .0024 N Do. One mile south of "Falrweather River",.n ne number 4 n i B6K1 38 Auger 4.4 4.4 0.0121 1.3 43.3 1.19 0. 0003 0.0004 6.4 Sand. B6K139 Do. 4.7 4.7 .0141 .9 30.4 .84 L - - Clay and sand. Two miles south of "Fa1 rweather River", line number 5 B6K131A Auger 0.0-5.3 5.3 _ 0.0126 0.9 27.6 0.76 0. 0004 0.0007 10.0 Fine sand and pebbles, B6K131B Do. 5.3-6.0 .7 - .0030 .6 18.9 .52 0001 .0002 2.4 Do. 6.0 B6K132 Do. 2.8 2.8 .0091 .4 13.2 .36 L - - Do. B6K133 PVC tube 1.7 1.7 .0020 .8 22.1 .61 L - - Do. B6K134 Do. .8 .8 .0010 .2 6.5 .18 L - - Do. B6K135A Auger 0.0-5.4 5.4 - .0131 1.6 47.1 1.30 0010 .0014 21.4 Do. B6K1 35B Do. 5.4-8.1 2.7 - .0070 .7 21.6 .59 L - - Do. 8.1 B6K136A Do. 0.0-5.2 5.2 - .0136 1.8 51.5 1.42 L - - Clay and fine sand. B6K136B Do. 5.2-8.0 2.8 - .0070 2.3 79.7 2.19 N - - Fine sand and pebbles. 8.0 B6K137 Do. 4.0 4.0 .0088 1.0 29.7 .82 00014 .0002 3.3 Do. I/ Ilmenite at $55 per ton. 2/ Gold at $150 per troy ounce. Table C-9.--Assay Data, Justice Creek, line number 6 i imeiii ic - uuiu-- Sample Sample Hole In-place Pounds Dollars Troy 02. Troy 02. Cents Interval , lenght, Depth, volume per per per per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd.J/ ton cu.yd. cu.yd.2/ Description B6K075 PVC tube _ 2.4 2.4 0.0029 0.09 3.2 0.09 0.0004 0.0007 10.5 Sand and gravel . B6K076 . Auger - 3.6 3.6 > .0123 .27 9.1 .25 .00009 .0002 3.0 Do. B6K077 Do. - 2.8 2.8 .0128 .14 5.4 .15 N - - Do. B6K078 Do. 0.0- 4.3 4.3 - .0079 1.30 44.6 1.23 N - - Fine sand. B6K078A Do. 4.3- 6.6 2.3 - .0069 .76 26.2 .12 .0002 .0003 4.5 F-1ne sand and pebbles n ; 6.6 i B6K079A Do. 0.0- 3.7 3.7 - .0098 2.27 74.5 2.05 .0006 .0009 13.5 Fine sand. B6K079B Do. 3.7- 7.2 3.5 - .0138 1.55 50.7 1.39 .0001 .0002 3.0 Fine sand and pebbles OJ B6K079C Do. 7.2-11.7 4.5 * .0172 .30 9.5 .26 N - Do. 11.7 B6K080A Do. 0.0- 3.7 3.7 _ .0089 1.25 38.5 1.06 .0002 .0004 6.0 Fine sand. B6K080B Do. 3.7- 4.4 .7 - .0030 1.43 62.1 1.71 N - - Sand and pebbles. 4.4 B6K081A Do. 0.0- 3.7 3.7 - .0113 1.05 35.5 .98 .0001 .0002 3.0 Fine sand. R6K081B Do. 3.7- 7.2 3.5 - .0098 .97 36.7 1.01 .0007 .0013 19.5 Sand and pebbles. 7.2 B6K082A Do. 0.0- 3.7 3.7 - .0089 .86 30.1 .83 .00004 .00007 1.1 Do. B6K082B Do. 3.7- 5.2 1.5 - .0059 .70 23.0 .63 .00007 .0001 1.5 Do. 5,2 B6K083 Do. ^ 1.9 1.9 .0039 .83 32.9 .90 L - _ Fine sand and pebbles B6K084 PVC tube - 2.8 2.8 .0034 .12 2.9 .08 L r > Sand and pebbles. B6K085 Auger - 4.0 4.0 .0098 1.54 56.6 1.56 .0007 .0012 18.0 Do. I/ Ilmenite at $55 per ton 2/ Gold at $55 per troy ounce. active beach grass-covered back beach approximate upper limit of ''swash zone at low tide 40 40 20' B6K087 B6K089 20' B6K09I B6K094 Sea Sea Level B6K095 Level -20 Explanation 0 20 40 60 . 4 B6K09I Auger or PVC tube i ii ii I i feet r sample location 6 5 10 15 20 meters Assay data given in table C-10 Mapped ay J. Ro*oj and A. Clough, jui> (976 Rgure C-15 Profile of beach two miles south of Justice Creek, sample locations, line no. 7 active beach 80 approximate upper limit of 'swash zone at high Nde 60' B6KQ73 * B6K074 end I-S oftd B6KII9 B6KH8IS 40' B6KI20 B SKI 23 20 B6KI25 Sea Level -20 80 60' 40' 20' Sea Level -20' B6K120 FXPL.ANATIQN Auger, PVC tube, or split tube sample location 5 10 i5 20 Assay data given in table C-11 Mapped by A Claugn ond J Ratoj, July Figure C-16 Profile of beach at the mouth of Echo Creek, sample locations, line no. 8 064 Table C-l(WAssay data, Two miles south of Justice Creek, line number 7 i iiiiem LI uuiii----- Sample Sample Hole In-place Pounds Dollars Troy oz. Troy oz. Cents Interval , lenqth, Depth , volume per per per per per Saropl e Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd.iy ton cu.yd. cu.yd.2/ Description R6K086 Auger - 3.5 3.5 0.0112 0.17 5.3 0.15 - - Sand and pebbles. B6K087A Do. 0.0- 3.7 3.7 - .0097 .74 22.6 .62 0.0016 0.0025 37,5 Fine sand and pebbles B6K087B Do. 3.7- 7.8 4.1 - .0133 .22 6.7 .18 .0003 .0004 6.0 Sand and pebbles. B6K087C Do. 7.8-11.7 3.9 - .0158 .23 7.7 .21 .0002 .0003 4.5 Do. B6K087D Do. 11.7-13.8 2.1 - .0143 .25 8.9 .24 L - - Do. B6K087E Do. 13.8-14.5 .7 - .0102 .18 5.6 .15 H - - Do. 14.5 B6K088A Do. 0.0-4.2 4.2 _ .0118 .28 8.1 .22 .00004 .00005 .8 Do. B6K088B Do. 4.2- 7.0 2.8 - .0098 .67 22.7 .62 .00004 .00007 1.0 Do. 7.0 B6K089A Do. 0.0- 4.1 4.1 _ .0102 .19 5.1 .14 H - - Do. B6KOB9B Do. 4.1- 7.8 3.7 _ .0107 .30 10.0 .28 L _ _ Do. B6K089C Do. 7.8-11.5 3.7 - .0164 .67 19.9 .55 H _ - Do. B6K089D Do. 11.5-14.2 2.7 - .0143 .21 6.8 .19 L - - Do. B6K089E Do. 14.2-14.8 .6 - .0046 .20 6.7 .18 L - - Do. 14.8 B6K090 Do. - 2.7 2.7 .0072 .90 25.1 .69 .0003 .0004 6.0 Do. - o B6K091 PVC tube - 2.2 2.2 .0027 .33 10.5 .29 H - Do. 1 B6K092 Do. - 1.0 1.0 .0012 .04 .8 .02 H - - Coarse sand. ON - - - (M B6K093 Auger 4.0 4.0 .0123 .11 2.5 .07 H Do. B6K094 PVC tube - 2.3 2.3 .0028 .20 6.4 .17 H - - Sand and pebbles. B6k095 Do. - 2.2 2.2 .0027 .19 5.8 .16 H - - Do. .0003 .0005 7.5 Do. iy Ilmenite at $55 per ton. 2/ Gold at $150 per troy ounce. -13 Assay data, Mouth of Echo Cfeek, line number 8 Ilmenltei iiiieni t Gold -. Sample Sample Hole In-Place Pounds Dollars Troy oz. Troy oz. Cents Interval , length, Depth, volume per per per .per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd.I/ ton cu.yd. cu.yd.2/ Description B6K116A Auger 0.0- 5.4 5.4 0.014? 1.6 52.3 1.44 Medium sand and pebbles. B6K072 Split tube Sampler 10.4-12.1 1.4 .0008 .6 19.3 .53 Clay, sand and pebbles. B6K072A Do. 12.0-14.0 1.2 .0006 .09 3.9 .11 Do. B6K072B Do. 14.0-16.0 1.4 .0006 .13 4.1 .11 Sand and pebbles. B6K072C Do. 16.0-18.0 2.0 .0010 .58 19.3 .53 Do. B6K072D Do. 18.0-20.0 1.3 .0006 .20 6.9 .19 Sand. B6K072E Do. 19.7-21.4 1.6 .0006 . .16 5.1 .14 Sand and pebbles. B6K072F Do. 21.4*23.1 1.7 .0007 .03 1.0 .03 Do. B6K072G Do. 23,1-24,8 .8 .0003 .13 4.7 .13 Clay, sand and pebbles. B6K072H Do. 25,0-26.7 1,1 .0004 .44 15.6 .43 Sand. 26.7 B6K119A .1 3.6 Medium sand and pebbles. Auger 0,0- 2.9 2.9.2' .0152 .001 B6K119B Do. 2.9- 3.1 .0046 .7 32.8 .90 Do. B6K073A Split tube n .64 21.9 .60 N Medium sand. i Sampler 5.0- 6.7 1.1 .0004 ON B6K073B Do. 6.7- 8.4 1.0 .0004 .31 9.6 .26 N Sand and pebbles. ON B6K073C Do. 8.4-10.2 .9 .0004 .34 11.7 .32 N Do. B6K073D Do. 10.0-11.7 1.0 .0005 .37 13.2 .36 0.0004 .0006 9.0 Coarse sand. B6K073E Do. 11.7-13.4 1.0 .0005 .01 .3 .01 N Coarse sand and pebbles. B6K073F Do. 13.4-15.1 .9 .0005 .01 .3 .01 N Do. B6K073G Do. 15.1-16.8 1.0 .0005 .03 1.1 .03 N Clay and coarse sand. B6K073H Do. 16.8-18.5 1.0 .0005 .03 1.0 .03 N Coarse sand. B6K073I Do. 18.5-20.2 1.2 .0006 .06 1.9 .05 N Coarse sand and pebbles. B6K073J Do. 20.2-21.9 .5 .0003 .02 .7 .02 N ... S1lt, fine sand and pebbles. B6K073K Do. 21.9-23.6 .9 .0005 .02 .7 .02 N S1lt'^med1Um sand and pebbles, B6K073L Do. 23.6-25.3 1.2 .0006 .18 5.3 .15 N Coarse sand. B6K073M Do. 25.3-27.0 .9 .0005 .12 4.1 .11 N Do. B6K073N Do. 27.0-28.7 .7 .0004 .04 1.2 .03 N - Doi:.. - '. ' ' ' . B6K0730 Do. 28.7-30.8 .7 .0003 .05 1.6 .04 N S1lt, sand and pebbles. B6K073P Do. 30.8-32.5 1.7 ' - .0003 .03 1.0 .03 N Fine sand. 32.5 Ilemntte at $55 per ton/. .# Gold at $150 per troy ounce. lable'C-ll--Assay data, Mouth of tcho creek, line number 8, cent. i imeni ic ------wo ui------Sample Sample Hole In-place Pounds Dollars Troy oz. Troy oz. Cents interval , length, Depth, volume per per per per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd. I/ ton cu.yd. cu.yd.2/ Description 86K123 PVC tube 0.0- 2.9 2.9 _ 0.0035 0.7 13.9 0.3ft N Medium sand anH pebbles. B6K074A Split tube Sampler 5.0- 6.7 .5 - .0003 .04 1.3 .04 N Fine Sand. B6K074B Do. 6.7- 8.4 .4 - .0002 .07 1.8 .05 N Do. B6K074C Do. 11.7-13.4 .4 - .0002 .29 10.9 .30 N - , Clay and pebbles. B6K074D Do. 13.4-15.1 1.5 - .0008 .33 11.1 .31 N Clay, coarse sand and gravel - B6K074E Do. 15.1-16.8 .6 .0003 '.03.16 4.6 .13 N Coarse sand. 86K074F Do. 16.8-18.5 .9 - .0004 1.1 .05 N ' Clay and sand. B6K074G Do. 18.5-20.2 1.1 - .0005 .05 1.8 .05 N Sand and pebbles. B6K074H Do. 20.2-21.9 1.2 - .0006 .05 1.7 .05 N Clay, sand and pebbles. B6K074I Do. 21.9-23.6 .9 - .0005 .08 2.5 .07 N Clay and coarse sand. B6K074J Do. 23.6-25.3 .8 - .0004 .12 4.3 .12 N Sand and pebbles. B6K074K Do. 25.3-27.0 .7 _ .0004- .43 14.9 .41 N Do. B6K074L Do. 27.0-28.7 .8 - .0004 .13 4.3 .12 N Clay, sand and pebbles. 86K074M Do. 28.7-30.4 1.0 _ .0005 .10 3.4 .09 N Do. B6K074N Do. 30.4-32.1 .8 - .0004 .06 2.1 .06 N Do. 32.1 B6K126 PVC tube 0.0- 3.5 3.5 .0042 .6 17.7 .49 L Medium sand and pebbles. 86K113A Split tube Sampler 5.2- 6.9 1.0 - .0004 .4 12.9 .35 N Sand. B6K113B Do. 6.9- 8.6 .4 . .0002 .1 2.6 .07 N Sand and pebbles. B6K113C Do. 10.3-12.0 .6 _ .0003 .5 17.1 .47 1. Medium sand and oebbles. B6K113D Do. 12.0-13.7 .7 _ .0004 .1 3.3 .09 o.onoz n.ooon 6.0 Do. 86K113E Do. 13.7-15.4 .7 _ .0003 .1 3.6 .10 N Coarse sand and pebbles. B6K113F Do. 15.4-17.1 .8 _ .0004 .1 3.6 .10 N Sand and pebbles. o B6K113G Do. 17.1-18.8 1.4 . .0007 .2 6. R .19 N Do. I 86K113H Do. 18.8-20.5 1.7 . .0004 5.2 194.9 5.35 N f)o. B6K113I Do. 20.0-21.7 1.2 _ .0004 .2 6.2 .17 N Do. {.B6K113J Do. v 21.7-23.4 1.1 _ .0006 .1 3.7 .10 N no. "B6K113K Do. * 23.4-25.1 .9 - .0005 .1 3.2 .09 N Clay, sand and pebbles. B6K113L Do. 25.1-26.8 1.0 - .0005 .1 3.5 .10 N Do .' B6K113M Do. 26.8-28.5 .5 _ .0002 .2 6.7 .18 N Sand and pebbles B6K113N Do. 30.2-31.9 .3 - .0001 .7 27.9 .77 N Do. 31.9 B6K114 Auger _ 3.6 3.6 .0101 4.7 T45.4 4.00 .0003 .0004 6.7 Medium sand and oebbles. B6K115A Do. _ 5.1 5.1 .0152 * 1.8 55.1 1.52 N Oo. 86K117A Do. _ 3.7 3.7 .0152 1.3 38.5 1.06 N Do. B6K118A Do. _ , 2.9 2.9 .0142 1.0 33.9 .93 N Po. B6K120A Do. 0.0-3.2 3.2 _ .0152 .9 32.0' .88 L Do. B6K1208 Do. 3.2-4.2 . 1.0 - .0112 .4 13.8 .38 L no. 4.2 B6K121 Do. 3.2 3.2 .0112 .7 26.0 .72 .0002 .0003 4.5 Do. 4.5 Do. B6K122 Do. 2.7 2.7 .0102 .7 26.8 .74.'28 .0001 .0003 .4 10.0 N no. B6K124 PVC tube _ 1.9 1.9 .0023 .4" B6K125 Do. 2.4 2.4 .0029 11.7 .32 L - Do. Oo. B6K127A Auger 0.0-5.8 5.8 .0152 2.2 6A.8 1.78 N 4.5 no. B6K1278 Do. 5.8-7.3 1.5 : .0091 .6 21.6 .59 .0002 .0003 7.3 P6K128A Do. 5.2 .0152 1.6 45.6 1.25 .OQ14 .0019 28.5 Clay, sand and pebbles. 0.0-5.2 no. B6K12RB Do. 5.2-7.8 2.6 - .0101 .6 17.1 .47 N 7.8 B6K129 Do. 3.8 3.8 .0091 .6 28.3 .78 .0008 .Onift 27.0 ' no. B6K130A Do. 5.0 .0152 .9 40.9 1.12 L - no. 0.0-5.0 Oo. B6K1308 Do. 5.0-7.7 2.7 - .0152 .2 6.6 .18 N 7.7 \f Jlmenlte at $55 per ton. 2J Gold at $150 per troy ounce. active beach .approximate upper limit af 40 »wa*h zone at low tide II s 20' B6KII2 Sea Level B6KI09 -20 Prospect trench see figure C-18 B6KIIO EXPLANATION _ --i """ Auger or PVC tube ot- 10 30 so feet 1 sample locations r J meters AssQy da|a gjyen jn table C-J2 Mapped by A. dough and J. Rataj, July, 1976 Figure C-17 Profile of beach one-fourth mile south of Echo Creek, sample locations, line no. 9 EXPLANATION A' Auger sample location 30 Plan Section B6KIOI B6KIOO B6K099 " 20' 86KIOO B6KIOI 10' trench floor' 0 10 20 30 40 I I j I 'eet T f r f meters trench continues an estimated 0 3 6 9 12 250 feet Section 88' B line number n B' 30' Assay data given in tableC-12 20' B6KI03 B6KI02 Sea floor - Level c Section C C1 B6K098 line number 10 30 B6K097 B6K098 20' B6K096 10' trench floor- Sea 'B6K096 Uevel Mapped by A Clough and J.Ra'aj, July 1976 Figure C-18 Prospect trench one-fourth mile south of Echo Creek,, sample lines nos, 10-12 sample locations C-68 Table C-12--Assay data, One-fourth mile south of Echo Creek and prospect trench, line numbers 9,10,11 and 12 Ilmenlte Gold---- «--- Sample Sample Hole In-place Pounds Dollars Troy oz. Troy oz. Cents interval, length, depth, volume per per per per per ^ Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd.iy ton cu.yd. cu.yd.2/ Description i tine number 9 R6K104 Auger 4.0 4.0 0.0091 3.6 118.9 3.27 0.0013 0.0022 33. Sand and pebbles B6K105A Do. 0.0- 4.2 4.2 - .0112 4.7 148.8 4.09 .00007 .0001 1.5 Do. B6K105B Do. 4.2- 8.0 3.8 - .0137 2.5 79.4 2.18 .0006 .0009 13.5 Do. B6K105C Do. 8.0- 8.1 .1 - .0015 5.4. 199.0 5.47 .0005 .0009 13.5 Do. 8.1 B6K106A Do, 0.0- 4.2 4.2 - .0081 8.2 293.7 8.08 .0019 .0035 52.5 Do. B6K106R Do. 4.2- 5.1 .9 - .0056 7.1 271.2 7.46 .0032 .006? 93. Do. 5.1 B6K107A Do. 0.0- 4.2 4.2 .. .0101 9.0 309.9 8.52 .0013 .0022 33. Do. B6K1078 Do. 4.2- 6.7 2.5 « .0137 3.4 101.3 2.79 .0013 .0019 28.5 Do. 6.7 B6K108A Do. 0.0- 4.6 4.6 - .0112 5.4 179.0 4.92 .0017 .0029 4 3,.' 5 Do. R6K108B Do. 4.6- 6.0 1.4 - .0101 2.9 99.0. 2.72 N - - Do. 6.0 B6K109 . PVC tube _ 1.5 1.5 .0018 .2 6.2 .17 N - - Do. B6K110 Do. - 1.7 1.7 .0021 .3 8.5 .23 N - - Do. B6K111 Do. - 4.5 4.5 .0055 .5 15.0 .41 .00004 .00006 ..9 Do. B6K112 Do. - 4.4 4.4 .0053 2.8 84.6 2.33 .00004 .OOOOfi .9 Do. L1 ne number 10 o B6K096A Auger 0.0- 4.2 4.2 0.0101 4.2 140.6 3.87 0.0003 0.0005 7.5 San I B6K096B Do. 4.2- 8.0 3.8 .0162 2.5 86.4 2.38 N - - Do. CTv VO B6K096C Do. 8.0-11.1 3.1 .0152 2.0 69.8 1.92 .00004 .00008 1.2 Do. 11.1 B6K097A Do. 0.0- 4.1 4.1 .0106 3.1 98.4 2.71 .0011 .0017 25.5 Do. B6K097B -Do. 4.1- 7.9 3.8 .0152 1.8 52.9 1.46 N - - Do. B6K097C Do. 7.9-10.0 2.1 .0091 1.2 41.2 1.13 .0004 .0007 10.5 Do. 10.0 B6K098A Do. 0.0- 4.0 4.0 .0142 2.1 68.5 1.88 N _ _ Do. B6K098B Do. 4.0- 7.8 3.8 .0132 .9 27.0 .74 N - - Do. B6K098C Do. 7.8-11.3 3.5 .0152 1.0 30.7 .84 N - - Do. 11.3 Line number 11 B6K102 Auger 3.5 3.5 0.0081 2.9 88.3 2.43 0,0003 0,0005 7.5 Sand and pehbles, B6K103 Do. 3.6 3.6 .0091 2.5 83.5 2.30 .0005 .0002 3.1 Do. Line number 12 - B6K099 Auqer 2.6 2.6 0.0061 4.8 138.6 3.81 N _ _ SandSan and pebbles, B6K100A Do. 0<0- 4.4 4.4 .0122 4.3 134.4 3.70 0.0006 0.0009 13.5 SanSand. B6K100B Do. 4.4- 8.4 4.0 .0162 1.4 48.8 1.34 .0004 .0007 10.5 SandSan and pebbles. B6K100C Do. 8.4-10.8 2.4 .0147 1.1 39.1 1.08 .0002 .0004 6.0 Do. 10.8 B6K101A Do. 0.0- 4.4 4.4 .0142 2.0 68.0 1.87 .0006 .0011 16.5 Do. B6K101B Do. 4.4- 8.5 4.1 .0162 2.0 65.7 1.81 .0012 .0019 28.5 Do. B6K101C Do. 8.5-10.8 2.3 .0147 3.1 93.6 2.57 .0007 .0011 16.5 Do. 10.8 I/ Ilmenlte at $55 per ton. |/ Gold at $150 per troy ounce. active beach approximate upper limit of swash zone at high tide 4O' 20' B6K193 B6KI94 Sea Level -20' gross-covered bock beach 4 forest-covered bock beach- 4O' B6KI99 B6K22I B6K2I9 I 20' Sea Level -20' Explanation B6KI93 Auger or PVC tube 2° -- r""""" sample location , *? , 6? feet 10 2'o meters Assay data given in tableC-13 Mapped by A. Kimball and J. Ratoj, July 1975 Figure C-19 Profile of beach three miles south of Harbor Point, sample locations, line no. 13 -active beach- | approximate upper limit of 40' swash zone at low tide 20' Seo level grass-covered back beoch- Sea level Explanation B7K032 PVC tube sample 20 40 """T"""""^ location i i I feet i I f meters Assay data given in table C-13 6 12 Mapped by J. Still and A. Kimball, Jul.y 1977 Figure C-20 Profile of beach three and one-half miles south of Harbor Point, sample locations, line no. 14 C-70 Table C^13 Assay data, Between Harbor Point and Steelhead Creek lines number 13 and 14 i iiircm tc - Sample Sample Hole In-place Pounds Dollars Troy oz. Troy oz. Cents interval , length depth , volume per per per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd. |/ ton cu.yd. cu.yd.2/ Description Three miles south of Harbor Point »line number 13 B6K192 PVC tube _ 2.5 2.5 0 .0030 0.1 3.0 0.08 N _ Fine to medium sand. B6K193 Do. - 4.4 4.4 .0053 .1 2.8 .08 N _ Do. B6K194 Do. - 4.7 4.7 .0057 .2 5.2 .14 N - Do. B6K195 Do. - 4.6 4,6 .0056 .1 2.7 .07 N - Do. B6K196 Do. - 4.2 4.2 .0051 .3 9.2 .25 L - Do. B6K197 Do. - 4.6 4.6 .0056 .8 22.5 .62 N - Do. B6K198 Do. - 4.7 4.7 .0057 2.0 57.9 1.59 N - Do. B6K199A Auger 0. 0-5.8 5.8 - .0133 2.2 75.8 2.08 N , Do. B6K199B Do. 5. 8-9.7 3.9 - .0112 1.0 30.4 .84 L - Do. 9.7 B6K219 PVC tube ,. 3.5 3.5 .0042 2.8 90.8 2.50 0.0002 0.0003 4.6 Do. B6K220A Auger 0. 0-5.7 5.7 _ .0148 2.1 61.6 1.69 N Do. B6K220B Do. 5. 7-7.7 2.0 - ,0112 1.1 33.9 .93 L _ Do. 7.7 B6K221A Do. 0. 0-5.7 5.7 _ .0123 2.2 44.6 1.23 L _ Do. B6K221B Do. 5. 7-9.3 3.6 - .0102 2.0 65.3 1.80 N - Do. 9.3 Three and one half miles south of Harbor Point, line number 14 o i B7K026A PVC tube 0. 0-2.0 2.0 0 .0024 0.2 5.4 0.15 N _ Coarse sand and pehhles. B7K026B Do. 2. 0-4.0 2.0 - .0024 .1 3.0 .08 N - Do. 4.0 . B7K026 Do. - 2.4 2.4 .0029 .1 2.3 .06 N _ Do. B7K027 Do. - 2.15 2.15 .0026 .1 3.3 .09 N - Do. B7K028 Do. - 2.1 2.1 .0025 .1 2.9 .08 N - Do. B7K029A Do. 0. 0-1.6 1.6 - .0019 .1 3.2 .09 N - Do. B7K029B Do. 1. 6-3.2 1.6 - .0019 L - - N - Do. 3.2 2.0 _ .0024 L N - Do. B7K030A Do. ' 0. 0 -2.0 - B7K030B Do. 2. 0 -4.0 2.0 - .0024 .1 3.6 .10 N Do. 4.0 .0024 .1 2.0 .06 N - Do. B7K031A Do. 0. 0 -2.0 2.0 Do. B7K031B Do. 2.0 -4.0 2.0 - .0024 .2 6.0 .17 N 4.0 - Do. B7K032 Do. _ 2.0 2.0 .0024 .2 5.9 .16 N N Do. B7K033A Do. 0. 0 -1.25 1.25 - .0015 .4 11.2 .31 15.4 .42 N Do. B7K033B Do. 1. 25-2.5 1.25 .0015 .3 2.5 1.65 .0020 .8 24.3 .67 N - Do. B7K034A Do. 0. 0 -1.65 - Do. B7K034B Do. 1. 65-3.3 1.65 - .0020 .7 26.4 .73 N 3.3 2.0 . .0024 2.9 107.0 2.94 N - Do. B7K035A Do. 0.0 -2.0 ~ Do. B7K035B Do. 2.0 -4.0 2.0 - .0024 .3 8.2 .23 N 4.0 \J Ilinenite at $55 per ton. 2/ Gold at $150 per troy ounce, continued from obove of C T9 O ro -OS ^ o -* o O O = O <" "*> ~ n>cr = Q o £ of rr ^~ O) X ro O o> 3 ST u> O -vl O-^ N) (0 rr (0 ye o tn O o1 o " U) CD *j oj^ S O si J__J continued below Table* C-14 Assa,y data, Topsy Creek,Une number 15 *J|U 1 »4 In-place Pounds Dollars Troy 02. per per Depth volume per Description Sampl e Type Ft. (m) cu:yd. Percent cu.yd. cu..yd.l_/ ton 0.23 N Sand and gravel. B6K200 Shelby tube 2.0 0.6'i 0.0033 0.3 8.2 Do. R6K201 Do. 2.05 I .6 jt .0034 1.0 30.1 .83 L .68 Do. B6K202 Do. 1.7 .51 -0028 1.1 24.7 Ho. B6K203 Do. 2.2 .7' .0037 1.4 35.0 .96 N 11.8 .32 N Do. B6K204 Do. 2.0 .6) .0033 .4 Do. B6K205 Do. 2.05 .6) .0034 .2 6.6 .18 N - L Sand and gravel on bedrock, B6K206 Grab .0058 L Sand on bedrock. B6K207 Do. .0068 1.9 53.3 1.45 L iy Ilmenite at $55 per ton. o i Table C-15--Assay data, Two miles south of Topsy Creek,line number 16 -i niieiii ie- --uuia- % In-place Pounds Dollars Troy oz. Troy oz. Cents Depth vol ume per per per per per Sample Type Ft. (m) cu.yd. Percent cu.yd. cu.yd.l/ ton cu.yd. cu.yd.2/ Description B6K208 Shelby tube 2.6 0.7; 0.0043 2.0 66.2 1.82 L _ _ Fine sand. B6K209 Do. 2.65 .7 .0044 15.2 495.0 13.61 0.0002 0.0003 4.5 Do. B6K210 Do. 2.5 .7 .0042 6.0 193.1 5.31 .0003 .0005 7.5 Do. B6K211 Do. 2.6 .7 .0043 2.2 74.6 2.05 L _ Do. B6K212 Do. 2.4 J, .0040 2.4 »8.0 .22 L , Fine sand and cobbles. B6K213 Do. 2.1 <> .0035 .9 29.6 .81 L _ .. Sand and cobbles. B6K214 Do. 2.5 -7 .0042 .2 6.7 .18 L _ , Coarse sand and pebbles. B6K21 5 Do. 2.95 .8) .0049 1.8 51,0 1.40 .0006 .0009 13.5 Soli and medium sand. B6K216 Do. .8 .2) .0013 5.7 61. Q 1.68 L , _ Mud and sand. B6K217 Grab - .0045 30.3 950.6 26.10 .0015 .0024 36.0 Surface heavy mineral concentration. B6K218 Channel 2.1 [ .6) .0038 13.2 422.1 VI .60 .00005 .00008 1.2 Sand.. ' I/ Ilmenite at $55 per ton. Z Gold at $150 per troy ounce. A' A back beach approximate upper limit of swash zone at low tide 40' - - 40' B6KI86 .B6KI89 yd 1 \ RCKIP7 / tri B6KI8I B6KIS2 86*183 H6KI84 E 22 ~- 7-! 86KI88 Level r garnet L »nf ... ,_, , . ?n' ~ Active beach DCWIQO .,« .. ^ , >>^ ^;'^/v /» *' ' ; B6KI82 PVC or shove hole ^^\ , ' 3?-.fe aoss- covered location n bock beach B6KI86 i Grab sample laca- . . \«?''i;^:^^^V.^;>^^L? L_ opproximote upper limit o1 40 "I swash zone at low tide * . "I B7K008 j ! 20 87X005 87K006___!!^2L ^ ^ "I o-^nno 87K003 87K004 ~~ *-«-»I«A>»I Of Mjljt ^^^ I B7KOQI 1, - i 1 1 ' Sea leve Q U -2Cr . 4 87K009 B7KOIO B7KOII 87KOI2 B7KOI3 B7KOI4 87KOI5 B7KOI6 ~ 40 1 "" 1 '"" ' ' ' ' ' ' frcontinued 20' _ Sea level 1 -20 Explanation B7KOIO PVC tube sample location ° "0 30 50 -* \^ \ i i 1 feet j meters Assay data given in table 0-17 3 5 10 6 Figure C-24 Profile of beach one mile north of LaPerouse Glacier, sample locations, line no. 18 C-74 Table C~16--Assay data, Dagelet River,line number 17 In-place Pounds Dollars Troy 02. Troy 02. Cents Depth volume per per per per per Sample Type Ft. (m) cu.yd. Percent cu.yd. cu.yd. I/ ton cu.yd. cu.yd. |/ Description Line number 17 B6K181 PVC tube 0.6 0 .2 0.0007 1 .0 30.1 0.83 N - - Sand, pebbles and cobbles. B6K1 82 Channel 1.6 .5 .0021 .4 12.6 .35 N - - Do. Do. 1.8 ,5 .0018 2 .3 74.4 2.05 N - - Do. B6K183 - B6K184 Do. 2.5 .R .0016 3 .0 97.1 2.67 N - Do. B6K185 Do. 1.5 .5) .0022 1 .8 56.4 1.55' N - - Do. B6K186 Grab .0023 12 .3 387.1 10.64 N - r Surface heavy mineral concentration. B6K187 PVC tube 2.2 ( .7) .0027 3 .5 112.3 3.09 N - * Do. B6K1 88 Do. 2.7 ( .8) .0032 11 .5 362.9 9.98 N - ~ Do, B6K189 Grab .0033 30 .6 972.2 26.74 0.0043 0.0068 102.0 Surface heavy mineral concentration. Other samples B6K190 Grab 0.0012 1 .2 38.3 1.05 N _ _ Silt. B6K191 Channel 3.0 (0.9) .0021 7 .7 249.2 6.85 N - - Sand. oI Ilmenite at $55 per ton. Gold at $150 per troy ounce. Table C^17--Assay data, One mile north of La Perouse Glacier, line number 18 i niitMii te- --oo iu------Sample Sampl e Hole In-place Pounds Dollars Troy oz. Troy oz. Cents interval, 1 ength, depth , vol ume per per per per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd.iy ton cu.yd. cu.yd.2/ Description B7K001A PVC tube 0.0 -1.68 1.68 _ 0.0020 L _ _ 0.00005 0.00008 1.2 Sand. B7K001B Do. 1.68-3.35 1.67 - .0020 .1 3.3 .09 N Do. 3.35 B7K002 Do. _ 1.7 1.7 .0021 L _ _ N Do. B7K003 Do. - 2.4 2.4 .0029 L - - N Do. B7K004A Do. 0.0 -1.83 1.83 - .0022 L - - N Do. B7K004B Do. 1.83-3.65 1.82 - .0022 .1 .4 .01 N Do. 3.65 B7K005A Do. 0.0 -2.0 2.0 - .0024 .2 6.2 .17 .00004 .00007 1.1 Do. B7K005B Do. 2.0 -4.0 2.0 - .0024 .3 10.2 .28 N Do. 4.0 B7K006A Do. 0.0 -2.03 2.03 > - .0025 1.7 38.8 1.07 N Do. B7K006B Do. 2.03-4.05 2.02 - .0025 .7 26.6 .73 N Do. ' 4.05 B7K007A Do. 0.0 -1.35 1.35 .0016 .2 3.9 .11 N Do. B7K007B Do. 1.35-2.7 1.35 - .0016 .7 30.2 .83 N Do. 2.7 ? B7K008A Do. 0.0 -1.8 1.8 .0022 .6 14.9 .41 N Sand and gravel ^ B7K008B Do. 1.8 -3.6 1.8 - .0022 1.7 60.3 1.66 N flo. 3.6 B7K009A Do. 0.0 -2.0 2.0 - .0024 .8 30.5 .84 N Do. B7K009B Do. 2.0 -4.0 2.0 - .0024 .2 5.2 .14 N Do. 4.0 B7K010A Do. 0.0 -2.05 2.05 - .0025 .8 25.5 .70 .00004 .00006 .9 Do. B7K010B Do. 2.05-4.1 2.05 - .0025 .6 17.7 .49 M Do. 4.1 B7K011A Do. 0.0 -2.0 2.0 - .0024 .6 22.8 .63 N Do. B7K011B Do. 2.0 -4.0 2.0 - .0024 .3 8.3 .23 N Do. 4.0 B7K012A Do. 0.0 -2.05 2.05 - .0025 .8 27.1 .75 N Do. B7K012B Do. 2.05-4.1 2.05 - .0025 .5 15.0 .41 N Do. 4.1 B7K013A Do. 0.0 -2.03 2.03 - .0025 .6 16.0 .44 N Do. B7K013B Do. 2.03-4.05 2.02 - .0025 .7 24.6 .fifi N Do. 4.05 B7K014A PVC tube 0.0-2.0 2.0 _ .0024 .6 19.0 ' .52 N Sand and qravel . B7K014B Do. 2.0-4.0 2.0 - .0024 .6 19.4 .53 N Do. 4.0 B7K015A Do. 0.0-2.0 2.0 - .0024 .6 18.6 .51 N Do. B7K015B Do. 2.0-4.0 2.0 - .0024 .2 6.6 .18 N Do. 4.0 B7K016A Do. 0.0-2.0 2.0 - .0024 .7 17.4 .48 N Do. B7K016B Uo. 2.0-4.0 2.0 - .002* .7 25.3 .70 ' N Do. 4.0 I/ Ilmenite at $55 per ton. ?/ Gold at $150 per trey otmce. 1 approximate upper limit of 30' 1 swosh zone ot low tirfe 20' _ 1 1 10' B7Kn. C B7KOJ7 87KOI8 B7KOI9 B7K020 1: sea . ____ _ |- - " i j | 1 level 1 -10' - 1 bock back beoch o beach o - 30' E B7K025 2 B7K024 20' 1 So B7K02I R7KO99B7KQ22 B7K023 - -JT 10' .£ ^______. 1 e o u sea level 1 Explanation B7K022_ PVC tube sample location 3 1 0 20 30 """i | feet i i i i | meters Assay data given in table C-18 0 S 10 Mapped by A. Kimboll and j. Still, July 1977 Figure C-25 Profile of beach one and one-half miles south of LaPerouse Gacier sample locations, line no. 19 B6K067 B6K066 B6K06S active beoch surface composed of coarse cobbles 86K065 B6K070 ( B6K069* B6K07I Explanation B6K065 PVC tube sample location Channel sample of B6K07I face of terrace Assay dota given in table C-18 o too 200 -opproximote upper limit of swosh I I I f««t zane at high tide ~ i r meters 0 20 40 6O Mapped by J Rataj and A Clough, July 1976 Figure C-26 Three and one-half miles south of LaPerouse Glacier, sample locations, line nos. 20-21 C-77 Table C~18--Assay data, Between La Perouse Glacier and Icy Point, lines numbers 19,20 and 21 Sample Sample Hole In-place Pounds Dollars Troy oz. Troy oz. Cents Interval, length, depth , volume per per per per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. cu.yd.]/ ton cu.yd. cu.yd.^ Description One and one-half mile south of La Perouse Glacier, Une number 19 B7K016 PVC tube - 2.05 2.05 0.0025 0.1 3.4 0.09 0.00004 0.00006 0.9 Sand. B7K017 Do. - 2.9 2.9 .0035 .2 6.7 .18 N - - Do. B7K018A Do. 0.0 -1.7 1.7 . .0021 .1 2.3 .06 N - Do. B7K018B Do. 1.7 -3.4 1.7 - .0021 .2 9.3 .26 N Do. 3.4 B7K019A Do. 0.0 -2.0 2.0 - .0024 * .1 2.7 .07 N - Do. B7K019B Do. 2.0 -4.0 2.0 - .0024 .3 11.3 .31 N Do. 4.0 B7K020A Do. 0.0 -4.0 2.0 - .0024 .3 5.5 .15 N Sand and pebbles, o B7K020B Do. 2.0 -4.0 2.0 - .0024 .2 6.7 .18 N Do. i 4.0 00 B7K021 Do. _ 2.2 2.2 .0027 .4 11.1 .31 N Sand. B7K022A Do. 0.0 -2.0 2.0 - .0024 .1 2.5 .07 N Do. B7K022B Do. 2.0 -4.0 2.0 - .0024 .2 6.5 .18 N - - Do. 4.0 B7K023 Do. _ 2.5 2.5 .0030 .9 26.1 .72 .0007 .0010 15.0 Do. B7K024A Do. 0.0 -1.4 1.4 - .OQ17 1.7 37.5 1.03 N - - Do. B7K024B Do. 1.4 -2.8 1.4 - .0017 .2 8.4 .23 N Do. 2.8 B7K025A Do. 0.0 -1.95 1.95 - .0024 1.4 48.6 1.34 N Do. B7K025B Do. 1.95-3.9 1.95 - .0024 .7 20.0 .55 N Do. 3.9 Three and one-half miles south of La Perouse Glacier Line number 20 B6K065 PVC tube 0.7 0.7 0 .0008 0 .1 2 .8 0 .08 Sand and gravel B6K066 Do. 3.5 3.5 .0042 .4 11 .7 .32 Do. B6K067 Do. 3.4 3.4 .0041 .6 14 .0 .39 Do. B6K068 Channel 9.0 9.0 .0029 1 .5 40 .9 1 .12 Do. Line number 21 B6K069 PVC tube 2.7 2.7 0 .0033 0 .3 8 .3 0 .23 Sand and gravel B6K070 Do. 2.1 2.1 .0025 .8 25 .6 .70 Do. B6K071 Channel 13.0 13.0 .0034 .2 5 .5 .15 Do. )/ Ilemrnte at $55 per ton. !/ Gold at $150 per troy ounce EXPLANATION forest-covered 0B6K052 B6K063-064 bock beach PVC tube sample location (samples of river bar) B6K05I 0 10 30 50 . I T . feet I I I meters 5 10 15 B6K060 I ine no. 22\ {se* m°P to right) B6K059 EXPLANATION B6K054 PVC tube sam- B6K055 pfe location B6K056 Channel sample B6K057 B6K06I °* fac« °f bo* B6K058 shore terrace B6K062 Assay data given in table C-19 active beach 200 400 feet meters 60 120 Mopped by A.Clouqh and J. Rataj, July 1976 Figure O27 Kaknqu Creek, sample locations, line no. 22 B6K026*B6K027 p--^. .B6K02: "*"\ K043 \ face of \ stream cut J2 \lw»"< \ line number 23 Samples 86K048-050 86X041-*^ located app. one mile east see figure C-7 olluviol sand and gravel EXPLANATION OB6K047 B6K030 Vertical channel sample approximate upper limit of V ® location swash zone at high tide OB6K046 B6K045 Grab sample location O 0 10 30 50 ii PAL MA BAY \ I I meters 0 5 IO 15 °B6K045 Assay data given in table 0-20 Mapped by J. Rataj and A Claugh, July 1976 Figure C-28 Mouth of " Raima River", sample locations, line no. 23 C-79 Table C-19--Assay data, Kaknau Creek, line number 22 In-place Pounds Dollars Depth volume per per Sample jy Type Ft. (m) cu.yd. Percent cu.yd. cu.yd. 2/ Description Line number 22 B6K051 PVC tube 0.9 (0.3) 0.0011 5. 4 162 .n 4. 46 Medium to coarse sand B6K052 Do. .6 ( .2) .0007 3. 1 98 .4 2. 71 Do. 86K053 Do. .5 ( .2) .0006 1. 8 55 .2 1. 5Z Do. B6K054 Do. 1.0 .3) .0012 3. 7 128 .5 3. 53 Do. B6K055 Do. 1.0 .3) .0012 1. 8 52 .4 1. 44 Ho. B6K056 Do. 1.5 .5) .0018 2. 7 75 .3 . 2. 07 Do. B6K057 Do. 1.5 .5) .0018 1. 2 35 .1 . 97 Do. B6K058 Do. 1.1 ' .3) .0013 . 5 13 .0 . 36 Do. 86K059 Do. 2.5 ' .8) .0030 3. 9 85 .1 2. 34 Do. 04 B6K06Q Do.- 1.4 .4\ .OOU 1.'. 3 37 .9 1." Do. B6K062 Do. .6 k .2} .0007 3 10.6 29 Do. Other samples B6K06T Channel 4.0 (1.2 0.0015 4.3 125.4 3.44 Medium to caarse sand. B6K063 PVC tube 1.3 ( .4 .0016 9.7 342.0 9.41 Do. B6K064 Do. 1.2 ( .4) .0015 4.6 146.3 4.02 Do. Tafilfe'C^Q.'-Assay data, Mouth of "Palma River", line nuirtber 23 - -i iinen i ce - ,(jO | a- ______In-place Pounds Dollars Troy oz. Troy oz. Cents Depth volume per per per oer Sample Type Ft . (m7 cu.yd. Percent cu.yd. cu.yd. I/ ton cu.yd. cu.yd.2/ Description Face of backshore terrace B6KC26 Channel 6.0 (1 .8) 0.0029 1.4 42 .6 1. 17 0.0007 0.0011 16.5 Sand and gravel B6K027 Do. 5.5 1j 7) .0032 .9 27 .8 . 76 N - - Do. B6K028 Do. 4.0 .0030 .8 24 .6 . 68 N - .- ' Do. B6K029 Do. 3.5 1 1 ) .0033 .8 24 .6 . 68 N Do. B6K030 Do. 3.5 (1 t .1) .0035 .7 21 .6 t 59 N Do. B6K031 Do. 3.5 .1 ) .0021 .5 15 .5 43 N - - Do. 86K032 Do. 3.5 1 1) .0030 2.0 61 .5 i! 69 N Do. 86K033 Do. 3.0 .9) .0025 1.9 58 .4 i. 60 N - - Do. B6K034 Do. 3.5 1 .1) .0034 1.6 49 .7 i. 37 N - - Do. B6K035 Do. 3.0 .9) .0017 1.2 36 .9 i. 02 N Do. w B6K036 Do. 3.0 .9) .0032 3.3 102 .3 2. 81 N - - Do. 86K037 Do. 2.5 .8) .0025 1.2 36 .5 1. 00 N Do. 86 KG 38 Do. 2.0 6 .0035 1.3 40 .5 1. n N Do. B6K039 Do. 2.0 6) .0020 .7 21 .4 f 59 .0002 .0003 4.5 Do. B6K040 Do. 2.5 ( 8) .0038 .2 6 .2 17 N Do. Line number '23 86K041 Channel 1.5 (0 -5) 0.0019 0.2 6 .3 0. 17 N Sand and gravel B6K042 Do. 3.5 (1 1) .0036 .6 18 .4 . 51 N Do. 86K043 Do. 3.5 (1 1) .0016 .4 12 .3 . 34 N Do. B6K044 Do. 3.0 ( .9) .0034 .4 16 .9 , 46 N Do. B6K045 Grab - - .0025 N - - N - - Coarse sand. 86K046 Do. - - .0026 .1 3 .1 t 09 N Sand and gravel 86K047 Do. - - .0022 .1 3 .0 08 N Do. '.. Other Samples' B6K048 Grab .. ,. 0,0018 2.6 82 .5 2. 27 N - - Sand and Gravel 86K049 Do. «. - .0022 2.4 75 .5 2. 08 N Do. B6K05Q Do. - - .0015 3.2 100 .6 2. 77 N Do. I/ Ilmenite -at $55 per ton Jf Gold at $150 per troy ounce. C-80 ___ Explanation | I Active beach deposit 0 B6KOI8 Auger or I I PVC tube sample A-H Gabbro (Lower location Paleozoic ? or Precambrian?) + B6S003 Split tube 0 100 300 sample location i I I feet M i meters 50 Assay data given in table n, B6K007 I ; 00, B6K008 B6K009 B6KOIO B6KOI1 Boussole Bay B6KOI8 approximate upper \ B6KOI9* limit of swash zone X at low tide B6K020- Mapped by A Kimball, J Still, J Rotaj, and A Clough, July 1976 Figure C-29 Boussole Bay , sample locations, line nos. 24-26 Ta,ble C^21 Assay data, Boussole Bay, line numbers 24,25 and 26 1 IHKMII LC-- ______uu , u _ ____. Sample Sample Hole In-place Pounds Dollars Troy oz. Troy oz. Cents interval length depth volume per per per per per Sample Type ft. ft. ft. cu.yd. Percent cu.yd. , cu.yd.iy ton cu.yd. cu.yd.2/ Description Line number 24 B6K001A Auger 0.0-1.6 1.6 - 0.0044 8.0 245.9 6.76 N Fine sand B6K001B Do. 1.6-3.2 1.6 - .0045 13.0 397.7 10.63 N Do. B6K001C Do. 3.2-4.6 1.4 - .0039 3.0 92.0 2.53 N Do. 4.6 B6K002 PVC tube _ 3.9 3.9 .0047 12.8 511.8 14.07 N Do. B6K003A Do. 0.0-2.1 2.1 - .0025 8.1 323.9 8.91 N Do. B6K003B Do. 2.1-4.5 2.05 - .0025 15.5 619.9 17.05 N Do. 4.15 B6K004A Do. 0.0-1.9 1.9 - .0023 1.0 30.0 .83 N Do. B6K004B Do. 1.9-3.8 1.9 - .0023 5.0 143.8 3.95 N Do. 3.8 B6K005A Do. 0.0-1.8 1.8 - .0022 2.0 54.7 1.50 0.0003 0.0004 6.0 Do. B6K005B Do.. 1.8-3.65 1.85 - .0022 2.0 70.2 1.93 N Do. 3.65 *? B6K006A Do. 0.0-1.9 1.9 .0023 2.0 68.7 1.89 N Do. oo B6K006B Do. 1.9-3.8 1.9 - .0023 NJ 2.0 55.4 1.52 N Do. * 3.8 Line number 25 B6K007A PVC tube 0.0-2.8 2.8 . 0.0034 4.0 127.2 3.50 N Fine sand B6K007B Do. 2.8-3.8 1.0 - .0012 6.0 213.8 5.88 N Do. 3.8 B6K008A Do. 0.0-2.0 2.0 - .0024 2,0 79.8 2.19 N Do. B6K008B Do. 2.0-3.9 1.9 - .0023 5.0 141.8 3.90 N Do. 3.9 B6K009A Do. 0.0-1.4 1.4 - .0017 4.0 211.1 5.81 N Do. B6K009B Do. 1.4-2.6 1.2 - .0015 4.0 132.0 3.63 N Do. 2.6 B6K010A Do. 0.0-1.7 1.7 - .0021 2.0 64.7 1.78 B6K010B Do. 1.7-3.7 2.0 - .0024 2.0 64.4 1.77 .00008 .0001 1.5 Do. 3.7 86 KOI 1 A Do. 0.0-1.0 1.0 - .0012 1.0 64.4 1.77 N Do. B6K011B Do. 1.0-2.2 1.2 - .0015 1.0 30.2 .83 N Do. 2.2 B6K012A PVC tube 0.0-2.8 2.8 _ .0034 2.0 59.9 1.65 N Fine sand B6K012B Do. 2.8-3.9 1.1 - .0013 4.0 141.3 3.89 N Do. 3.9 B6K013A Do. 0.0-2.5 2.5 .0030 3.0 88.7 2.44 N Do. B6K01 3B Do. 2.5-3.9 1.4 - .0017 2.0 65.5 1.40 N Do. 3.9 .88- B6K01 4A Do. 0.0-1.9 1.9 _ .0023 1.0 32.1 N Do. B6K014B Do. 1.9-3.8 1.9 - .0023 3.0 86.3 2.37 N Do. 3.8 Table C-21 Assay data, Boussole Bay, line numbers 24,25 and 26, cont, Ilmenite Gold Sample Sample Hole In-place Pounds Dollars Troy oz. Troy 02. Cents Interval length depth, volume per per per per per Sample Type ft. ft, ft. cu.yd, Percent cu.yd. cu.yd.l/ ton cu.yd, cu.yd.2/ Description o 1 00 Line number 26 OJ B6K015A PVC tube 0.0-2.2 2.2 - 0.0027 3.0 98.0 2.70 N Fine sand B6K015B Do. 2.2-3.75 1.55 - .0019 4.0 136.8 3.76 N Do. 3.75 B6K016 Auger _ 6.0 6.0 .0150 2.0 33.6 .92 N Do. B6K01 7 Do. - 4.8 4.8 .0156 1.0 23.7 .65 N Do. B6K018 Do. - 3.6 3.6 .0084 1.0 22.8 .63 L Do. B6K019 Do. - 1.45 1.45 .0030 .8 8.9 .24 N Do. B6K020 Do. - 1.3 1.35.0 1.3 .0036 .8 15.7 .43 N Do. B6K021 Do. - 5.0 5.0 .0162 5.0 121.3 3.33 N Do. B6K022 Do. - 4.4 4.4 .0120 3.0 80.0 2.20 N Do. B6K023 Do. - 3.9 3.9 .0096 5.0 140.6 3.87 N Do. B6K024 Do. - 2.3 2.3 .0072 2.0 48.6 1.34 N Do. B6K025 Do. 1.5 1.5 .0048 .7 12.6 .35 N Do. Other Samples B6S001A PVC tube 0.0-1.9 1.9 - 0.0023 19.0 701.5 19.30 sand B6S001B Do. 1.9-3.9 2.0 - .0024 14.0 519.5 14.29 Do. B6S001C Do. 3.9-5,8 1.9 - .0023 7,7 252.0 6.93 Do. B6S001D Do. 5.8-8.0 2.2 - .0027 6.1 212.0 5.83 Do. B6S001E Do. 8.0-8.9 .9 - .0011 10.2 318.9 8.77 Do. 8.9 B6S003A Split tube Sampler - 1.2 1.2 .0001 1.2 29.2 .80 Do. i/ Ilmenite at $55 per ton. 2J Gold at $150 per troy ounce Table C-22.--Pacific beach sands, sample sections and weighted average grade of commodities along the section, showing the parameters used in the grade calculation Average distance Average Average weighted grade Density, Length Number between hole Gold, trov pounds Line of line, of holes, depth, Ilmenite, ' ounces per tyumber ft. holes ft. ft. percent cubic yard cubic yard 1 900 19 50 3.8 1.13 0.0002 3,133 2 465 9 50 6.3 1.03 .0002 2,876 3 360 9 50 2.8 .15 - 3,146 4 47 2 50 4.6 1.09 .0003 3,355 5 210 6 50 4.6 1.25 .0004 3,061 6 525 10 60 4.9 .89 .0003 3,430 7 410 9 50 5.6 .36 .0003 2,884 8 805 16 50 11.1 .69 .0001 3,409 9 590 9 70 4.7 4.18 .0014 3,267 10 100 3 50 10.8 2'. 18 .0003 3,291 11 50 2 50 3.6 2.70 .0002 3,201 12 100 3 50 8.1 2.64 .0009 3,235 13 780 11 80 5.4 1.28 .00002 3,000 14 525 11 50 3.1 .37 - 2,968 15 356 6 85 2.0 .73 ' - 2,809 .16 865 9 110 2.3 3.99 .0002 3,158 17 310 7 50 1.8 4.21 - 3,178 18 750 16 50 3.6 .53 .000007 3,174 « 19 422 10 45 3.2 .43 .00009 3,080 20 350 4 185 4.2 1.02 - 2,668 21 60 3 55 5.9 .29 - 2,882 22 285 n 30 1.4 2.48 - 2,916 23 40 4 15 2.9 .43 - 3.099J/ '4.0 24 450 6 100 6.81 .00004 3,312 25 600 8 85 3.4 2.82 .00001 3.44A 26 900 10 100 3.2 2.69 - 2,518 T/ Estimated figure. C-84 9-1267 one-fourth mile south of Echo Creek. Values found in the samples ranged from 1.5 to 93 cents in gold per cubic yard, with a weighted average, grade of 21 cents in gold per cubic yard for the sample line, i assuming $150 per troy ounce for gold. This gold grade was the best j ! of the 26 sample lines. Ilmenite grades of greater than 3.0 percent \ 5 i were obtained from sample lines located at one-fourth mile j i south of Echo Creek, at the Dagelet River and at Boussole Bay. i 10 13 15 ! 23 C-85 9-1267 Resource calculations Inferred resources Resource calculations were made using the method of sections with the grade between sections computed by the rule of gradual changes,, Inferred resources were computed for 12 reserve blocks using the 5 following assumptions. The grade of a sample line was considered to extend a distance equal to one-half the hole spacing beyond each end of the line. Geologic evidence suggests that the beach deposits located between Lituya Bay and Justice Creek have a depth greater than that confirmed by sampling; thus, for blockycovering these deposits Id- I the average hole depth was projected to twice the extent measured. j Adjacent sample lines were connected to form blocks up to two miles in j length. If the connected sample lines were separated by less than 1,00 13 feet, the block was projected for an additional 300 feet on either end. 14 ! For widely spaced lines, grade was considered to persist for 300 feet 15 on either side of the sample line. Table C-23 details the parameters 16 Table C-23 near here 19 j used to calculate tonnage and grade for 12 inferred resource blocks in | the area. Table C-24 summarizes the extent and value of the inferred 21 22 Table C-24 near here 23 24 resource blocks. Figure C-30 shows the locations of the blocks. ; C-86 Table C-23. Pacific beach sands, inferred resource calculations Gross Gross in-place Average in-place Average Average value for weighted value weighted weighted ilmenite, grade of for gold Projected Projected Area of Distance dens i ty , grade of dollars gold, troy dollars Line length of depth of section between Volume, Ibs. per ilmenite per ounces per per No. Block line, ft. line , ft. sq. ft. lines, ft. cu ...yd. cu. yd. percent cu. yd. I/ cu. yd. cu. yd. I/ 1 950 3. 8 3,610 1 6,340 804 ,828 3,011 1.1 0.91 0.0002 0.03 2 \k 515 6. 3 . 3 410 2. 8 1,148 2a 4,929 145 ,497 3,204 .4 .35 .00007 .01 4 97 4. 6 2b 3,960 120 ,413 3,141 1.2 1.04 .0004 .06 5 260 4. 6 1,196 6 585 9. 8 5,733 3 8,976 1 ,809 ,329 3,172 .6 .52 .0003 .05 7 460 11. 2 5,152 8 855 22. 2 18,981 . 4a 1,320 615 ,633 3,374 1.6 1.48 .0005 .08 9 660 9. 4 6,204 10 150 21. 6 3,240 4b 35 24 ,5672/ 3,275 2.3 2.07 .0003 .05 11 100 7.2 720 4c 35 19 ,542i/ 3,227 2.7 2.40 .0008 .12 12 150 16. 2 2.430 13 860 5. 4 4,644 5 2,904 345 ,630 2,991 1.0 .82 .00001 .002 14 ' 575 ' 3. 1 1,783 15 441 2. 0 882 6 3/ 19 ,600 2,809 .7 .54 - , - ' 16 975 2. 3 2,243 7 12,400 663 ,859 3,162 4.0 3.48 .0002 .03 17 360 1. 8 648 18 8 800 3. 6 2,880 3/ 64,000 3,174 ,5 .44 .000007 -.001 19 467 3. 2 1,494 9a 9,768 676 ,705 2.833 .8 .62 20 535 4. 2 2,247 9b 200 27 ,093,j-/ 2,178 .9 .67 21 115 5. 9 679 * 22 JP 315 . 1. 4 441 y 9 ,800 2,916 2.5 2.00 23 11 55 2. 9 160 3/ 3 ,556 3,099i/ .4 .34 . - 24 550 4. 0 2,200 12a 500 67 ,096l/ 3,385 4.8 4.47 .00004 .01 25 685 3. 4 2,329 12b 1,000 133 ,1062/ 2,894 2.7 2.15 26 1,000 3.2 3,200 \J Ilmenite at $55 per ton, gold at $150 per troy ounce. II Includes a projected lateral distance of 300 feet at end of block, V Projected lateral distance of 300 feet on each side of line. \J Estimated figure. . C-87 Table C-24. Pacific beach sands, summary of the extent and value of the inferred resource blocks Weighted 1 6,340 515 to 950 3.8 to 6,3 805 ,000 1.1 0.0002 2 8 ,889 97 to 410 2.8 to 4.6 266,000 .8 .0002 3 8,976 460 to 585 9. 8* to 11.2 1,809 ,000 .6 .0003 4 1 ,620 100 to 855 7.2 to 22.2 660 ,000 1.7 .0005 .5 2 ,904- 575 to 860 3.1 to 5.4 346 ,000 1.0 .00001 6 600 441 2.0 20 ,000 .7 - 4 7 12,400 360 to 975 1.8 to 2.3 664 ,000 - 4.0 .0002 8 600 800 3.6 64,000 .5 .000007 9 10 ,268 115 to 535 3.2 to 5.9 704,000 .8 - 10 600 315 1.4 10,000 2.5 - 11 600 55 2.9 4,000 .4- - 12 2 .100 550 to 1,000 3.2 to 4.0 200 ,000 3.4 .00001 Total volume: app. 6,000,000 cubic yards Inferred resources: app. 120,000 tons ilmenite app. 1,200 troy ounces of gold C-88 9-1267 Figure C-30 near here These calculations show that at the inferred resource level there are 6 million cubic yards of material with an average grade of one percent ilmenite with a value of 85 cents per cubic yard, assuming $55 per ton for ilmenite. Average gold values were less than $0.01 per cubic yard, assuming $150 per troy ounce for gold. 10 12 15 16 17 18 19 21 22 23 25 C-89 39°QO' Location of resource block no. 3 , size not to scale. 137*30 Base from U.S. Geological Survey Mt. Fairweother |: 250,000 1961 Figure C-30 Location of resource blocks for Pacific beach sands C-90 9-1267 i I Within the inferred resource blocks, there are two areas with I : i values significantly higher than the average grade. Resource block i 3 number 12 at Boussole Bay contains 200 thousand cubic yards of i -» j material averaging 3.4 percent ilmenite £o£ 3A i 5- I average value of $2.92 per cubic yard. Within resource block number 4'> 6 i along sample line number 9, we estimate that there are 134 thousand 7 ; cubic yards of material containing 4.2 percent ilmenite worth $3.77 8 i per cubic yard and an additional 21 cents per cubic yard in gold. i 7 i Hypothetical resources | 10 j Beach deposits not sampled and lying beneath the 12 inferred 11 I resource blocks, and the volume of material between the inferred I 12 i blocks can be included in an additional hypothetical resource estimate1 13 i An average depth of 6.4 feet was used in the inferred estimate and- the! n j deepest sample collected to 32.5 feet. Bedrock was not found in any | I i '5 j samples. It is- reasonable to assume that an additional 6 million ; 1 j 16 ! yards of material probably lies beneath the inferred resource blocks. | i i 17 | The total surface area sampled was about one square mile while i is \ the total area of beach deposits between Sea Otter Creek and Boussole I i 'p , Bay is eight square miles. The total hypothetical resources estimated :o i are 90 million yards [(7 x 12 million) + (6 million)]. The grade of , 21 j this material is probably similar to that estimated for the inferred ! : 22 ! resources. ; I i 23 ; Remainder of the province \ "- Three localities south of Lituya Bay comprise the additional i 25 j mineral occurrences in the Lituya province. Gold is found in an C-91 9-1267 hydrothermally altered zone in upper Fall Creek. Chalcopyrite occurs I in a gabbroic dike in granitic rock on the west side of Crillon Inlet. Five claims were filed on a prospect at Mudslide Creek. Table C-25 provides information on these occurrences. Table C-25 near here 10 13 17 13 19 21 22 25 C-92 Table C-25. Lituya province, mineral occurrences not discussed in text. No. on Name of Main Source of plate III prospect Cammedity Locution Description of deposit Mining claims Samples I/ information Remarks West side Cu, Ni West side of Iron-stained float on top None recorded The float contained 1»600 This investi Steep cliffs of Crillon Crillon Inlet of a scree pile that pro- ppm copper, 0.15 ppm gold, gation; on the west Inlet near Lituya bably came from the imroe- (all AAS analysis), 1 ppm Kennedy and side of Bay. diate area. The float con silver, 2,000 ppm nickel Walton, 1946, Crillon Inlet sisted of quartz, chlorite, and 300 ppm cobalt. p. 71; immediately hornblende, epidote, goethlte MacKevett, above the and pyrite. Walton (1946, and others, mineralized p. 711 reports a conspicuously 1971, p. 53, float were i iron-stained gabbroic dike location investigated VO cutting granitic rock on the no. 84. at an ele U) western shore of the south vation of 800 east arm of Lituya Bay that feet. The contains an estimated 1 per source of the cent cha.lcopyrite. mineraliza tion was not found. A possible iron* stained source for the float was spotted -half way up a slabby cliff face on the southeast side of Lituya Bay. This may be Walton'a gabbroic dike. Time did not per mit its in vestigation. Table C-25. Lituya province,occurrences not dir.cussed in text, con't. No. on Name of Main Source of Jvlate ill prospect Commodity Location Description of deposit Mining claims Samples I/ information Remarks 2 Mudslide South side of The rocks in the area of Lode; Billy Sample analysis of in place This investi The exact Creek Lituya Bay the claims consist of Goat and Billy greenstone and of stream gation! location of Mudslide serpentinized greenstone Goat #2. sediments in the approxi- Juneau . the deposit Creek drain volcanics, with minor Placert Billy mate area of the claims in- claims the claims age probably metadiorite and gneiss. Goat 13-15. dicated traces of copper. Records . are staked below 1,500 ~ The volcanics contain Claims recorded over is UO-- Y, 000 ft. in very small , widely dis in 1972 with certain. De elevation. tributed amounts of assessment work posit was s low grade copper bearing filed in 1973 : searched for minerals. i but not found {during this ' investigation.' . 3 Pall Creek Au Upper drain- Gold and silver values None recorded In the upper Pall Creek MacKevett , Miller (1954 » ages of Coal, are reported from drainage, a 0.7 ft. channel 1971, p. 64. unpub. data , Fall, and Mud samples of yellow- and sample was taken across a location no. in Rossman , slide Creeks. red-stained hydro- jasper rich zone in green 85; 1959) states thermally altered zones stone. The sample assayed Rossman, that similar in sedimentary and at 0.02 oz Ag/ton. Abun 1959, p. 57- hydroyherma 1 ly volcanic rocks. dant finely-disseminated 58, figure altered rock pyrite and a trace of 9; occurs in the powellite occurs in the this investi upper part of greenstone. Rossman (1959) gation. the Topsy Creek reports that most of the drainage. zones contained no precious , metal values. The best values obtained were from a sample near upper Coal Creek that contained 0.24 oz. Au/ton and 0.02 oz. Ag/ton. I/ All sample values cited were obtained from semiquantitative spectrographic analysis, unless noted otherwise. 9-1267 Fairweather province Introduction Much of the province is comprised of schist, gneiss and associated! rocks rich in hornblende to the west and in biotite to the east. Some of the highest peaks of the dominant Fairweather Range are composed of j ! a series of layered and unlayered gabbro intrusives. Small Tertiary ' and/or Cretaceous granitic bodies occur in widely-separated areas, j | with the major grouping occurring in the northeast part of the province. 10 Important nickel-copper deposits are associated with the largest of the layered gabbro intrusives, the Crillon-LaPerouse stock. This body of 130-square mile extent has a saucer-like structural shape, j 13 I with layering distinguishable on the basis of constituent minerals and i jtexture, and has an exposed stratigraphic thickness of more than 32,000 15 feet. Neither the top nor bottom of the stock is exposed. The best 16 known nickel-copper deposit occurs along the eastern periphery of the 17 stock and is named the "Brady Glacier nickelideposit." Other 18 mineralized areas near the periphery of the LaPerouse stock are known, 19 a few of which were examined during this study. Several were not examined either because their elevations were high enough to require helicopter transport during the clearest weather when the helicopter 22 was in particular demand and other priorities took precedence, or they 23 |were physically unapproachable because of the terrain to be - » crossed. L. 095 9-1267 , | Two localities near the north end of the stock which were visited i 2 are described in the text following the description of the Brady nickel 3 |deposit. Available information about others not visited is briefly | 4 summarized in the text and is covered further in table C-27 at the end 5_ !of the Crillon-LaPerouse stock text section. Locations are shown on I 6 plate III. 7 : The east side of the stock to the north of the Brady deposit is i a ;so extremely rugged, poorly exposed, and poorly known that although 9 imineralization is probable there none has been reported. 10 i Three other gabbro bodies, the Fairweather stock, the Astrolabe- Delangle stock and a gabbro body near Mount Wilbur are outlined on 12 plate*I. The first two are known to have iron, titanium and copper i 13 i mineralization associated with them and, in addition, the first has i 14 nickel, chromium and platinum associated with it. The three stocks i5_ I known to contain metallic mineralization are discussed in appropriate 16 ! sections of the text which follows. The Mount Wilbur body is not i 17 j discussed. 13 i Crillon-LaPerouse stock and vicinity Brady Glacier nickel I deposit A Introduction The Brady Glacier nickel-copper deposit, about five miles east of 22 I the summit of Mt. LaPerouse, is situated on the eastern periphery of i the Crillon-LaPerouse layered, mafic body. The deposit lies under ! moving ice of Brady Glacier except for less than five acres of expo- 5_ | sure in two nunataks. Three nunataks are reported during some light i______C-96 9-1267 snow years. The deposit is about 12 miles north of Dixon Harbor and has a maximum elevation of about 3,500 feet. The deposit was discovered by Fremont Mining Co. in 1958 and was covered by 224 claims. By late 1959 this company had drilled 32 i diamond drill holes (MacKevett and others, 1971). Newmont Exploration j i Limited became manager of the property through a lease agreement with i Freemont in I960, and during that same year and the next drilled an ; i additional 14 diamond holes. i Twenty mining claims were patented in 1965 and the remaining I 10 unpatented claims were allowed to lapse. Union Pacific Mining Corpora-i tion and Cities Service Minerals Corporation have recently joint- is ventured the property with Newmont retaining managership. Geology and mineral deposits \ . . ----- According to H. R. Cornwall, who visited the deposits in 1966 | is-! (MacKevett and others, 1971), the host rocks of the Brady Glacier i 16 | deposits are dominantly peridotite with olivine gabbro common and 17 | with a small amount of dunite. The Small and High Nunataks, previously i 13 j mapped by Newmont Exploration Limited, show indistinct layering where 19 ! peridotite overlies gabbro, dipping gently to moderately southwestward. 20 On the basis of limited diamond drill hole information and visual inspection of the surface nunataks Cornwall said that pyrrhotite, 22 pentlandite, and chalcopyrite. occur in the above host rocks as dissemi 23 nated grains, veinlets, and lens-shaped masses up to 35 feet long and 24 five feet in diameter. Some surface sulfide masses run two to three i 25 \ percent nickel and one to 1.4 percent copper. He further stated that C-97 9-1267 "a large area about 1,000 feet in diameter beneath the Glacier i | i i 1,000 feet southwest of the nunataks appears to contain 0.3 to 0.6 j | j percent nickel and 0.2 to 0.4 percent copper in gabbro and peridotite. "' I | ] Holes 200 and 700 feet south of the nunataks revealed higher grade ! i 5 Ij mineralization, and two holes intersected 100 feet of sulfide minerali I i | zation averaging 0.4 percent copper and 1.0 and 0.7 percent nickel, ( ! ; respectively. He also noted that the area surrounding the nunataks I appeared at that time to offer the greatest promise for commercial ore , i ; bodies and that more exploration was needed for reliable evaluation of 10 the deposits. Since 1961, 36 more holes have been drilled. Quoting from j i 12 Richard D. Ellett of Newmont (1975) : "To the best of our knowledge | the deposit represents the largest known nickel deposit within the '. United States. The deposit has been defined by numerous holes (82) i drilled through many hundreds of feet of ice from the surface of the i glacier. The investigation has indicated substantial additional reserves exist in adjacent areas where surface conditions make further : drilling hazardous, so that further exploration must be conducted from underground openings." and Htmmelberg Recent work by Czamanske, Calk, Loney, / (1977) on core samples has 21 ! indicated that massive sulfides up to 15 feet thick have been penetrated ?2 by drilling. In some areas 400 to 650- foot thicknesses of rock are i i 23 'suggested to contain networks of sulfide veinlets that are intercon- 24 'necting and average 0.3 percent copper and more than 0.4 percent 25 j nickel. The deposit is predominately disseminated sulfide in gabbro C-98 and peridotite. Disseminated ore may average about 0.02 ppm PGM (platinum group metals) and massive ore about 1.30 ppm PGM. The limits of the deposit have not been determined. Tonnage At least 90 million tons of mineralized rock are indicated within the boundaries of the 20 patented claims, having a grade of 0.53 percent nickel and 0.33 percent copper, based on the number of contained pounds of nickel and copper given in testimony before the Senate Committee on Interior and Insular Affairs by an official of the managing company, October 7, 1975 (Ellett, 1975), and on grade figures given in a state ment in the Congressional Record the following year (Stevens, 1976). More than 100 million indicated tons having an average grade of 0.5 percent nickel and 0.3 percent copper are reported by the USGS (Czamanske and others, 1977) which also closely correlates with the number of pounds of nickel and copper reported in the 1975 testimony cited above. At February 1978 metal prices the gross in place metal value of the indicated tonnage using the reported pounds of nickel and copper is $2.46 billion. Platinum group metals which are present have not been added into these calculations because, although an average grade for disseminated ore reported above might be used for minimal average assay for the deposit as a whole, it is not broken down into the relative amounts of component platinum group metals or is it necessarily determined from C-99 an adequate-sized sample to accurately represent the ore body. The presence of platinum group metals would probably add several percent to the value of the deposit. Since the limits of the deposit have not been determined and there is a high geologic probability that the body extends an unknown distance beyond the limits of the area probed by drill holes, additional tonnage at least equal to the 90 to 100 million tons of indicated tonnage should be inferred. However, "inferred" implies that specific indicated tonnage limits are established. This cannot be done since complete data on which the indicated tonnage calculation was based have not been made public. Ice thickness measurements taken to support USGS regional gravity surveys, made with a new radio-echo sounding technique (Watts and England, 1976), suggest that an ice-filled canyon with its bottom below sea level passes a mile or two to the north of the Brady deposit and possibly could somewhat restrict lateral extension of ore body C-100 dimensions in that direction. No ore-body shape information has been made public; however, a rough volume figure based on known tonnage might be illustrative. Using a 90 million ton figure and a rough, but reasonable conversion from weight to volume, the olume comes out to be roughly on the order of a billion cubic feet. Converted to hypothetical shapes this would be a volume equivalent to a cube of nearly 1,000 feet on a side or a sphere nearly 1,400 feet in diameter. Briefly restating, the Brady Glacier nickel deposit, one of the largest known nickel deposits in the United States, is associated with ultramafic rocks that are very probably related to the 130 square mile LaPerouse layered, mafic intrusive (cumulate) stock, It has excellent potential for being much larger than now known. Its limits have not been determined. Other mineralized areas near the Crillon-LaPerouse stock North wall of South Crillon Glacier Several extensive iron-stained zones in the layered gabbro near its contact with amphibolite schist are found on the north wall of the South Crillon Glacier. These zones appear to be up to 20 feet thick, are intensely iron-stained and can be traced visually for C-101 9-1267 thousands of feet. They are apparently poorly defined shear zones that cross the poorly defined layering of the gabbros. Most of these zones are inaccessible because of frequent ice or rock falls and j precipitous terrain. Access to one zone was gained (fig. C-32) . About 5 FigureC-32near here 120 feet of exposure was accessible between an overhanging cliff to the north and a snowbank to the south. The zone is from six to eight feet thick and is composed of intensely iron-stained/ sheared gabbro 10 containing disseminated pyrrhotite and chalcopyrite that occasionally coalesces into small, lenticular sulfide pods. Sample locations and 12 data are shown in figureG53 and tableG26a. A 0.6-foot thick, 12-foot 13 Figure&33 and tableG26anear here 15 long sulfide pod containing pyrrhotite, chalcopyrite, and pentlandite 17 I assayed 3,000 ppm copper, 2,500 ppm nickel, and 700 ppm cobalt. Samples i is j across the remainder of the zone contained up to 2,400 ppm copper, 700 i 19 | ppm nickel, 150 ppm cobalt and 0.10 ppm gold. This zone is too small i i 20 and low in grade to exploit but shows that copper-nickel mineralization i 21 j similar to the Brady deposit is found at the north end of the stock i 22 I approximately 15 miles away. Other stained layers in the immediate 23 area and some stained zones thousands of feet across in the general area were more difficult to access. 25 C-102 137° 15' EXPLANATION Glacial ice and per manent snowfields Hornblende gneiss and schist (Lower <^ Paleozoic? or Pre- A> cambrian?) f8?40 h£" "-* South^-^^e si Contact, generalized from plate I 7SOII-OI5 X' Sample location Assay data given in tables 26a and 26b N p?y.--..- Contour interval 100 ft. 0 .5 ! mite kilometers Base from U.S.Geol. Survey 1:63,360 (.5 Mt. Fairweather C'4, 1961 Figure C-32 North and South Crillon Glacier mineralized zones sample locations 0103 El 3600ft. N 0 5 10 20 FEET I I METERS El. 3575 ft snow cover Mopped by J. Still and A.CIough, July 1976 EXPLANATION Pyroxene gabbro NT Strike and dip of shear zone (Lower Paleozoic? or Precambnan?) ^ Massive sulfide lens Shear zone with intensely iron- "" stained sections,containing pyrrhotite Chip or channel sample location ond cholcopyrite as disseminations and in massive lenses Assoy dota given in table C-26a Figure C-33 North side of the South Crillon Glacier, sample locations C-104 r OH ON 000^ oooc TO 0' S' OOhT, Sb k O/ o 00^ 00^ Oj'O O OS OOb M ou atz I'l m dN 001 QSS g j o -fc^r, L' L'\ I u -t' 051 oog N oo/ /J'O CJ.D N £' OS4/ o-z; S' OL 2*0 e 001 uoijduosao a TJ j (UJ) ajdaios 33 1 j .:__. .Xi 9-1267 South wall of North Crillon Glacier A mineralized zone on the south side of the North Crillon Glacier was reported by Kennedy and Walton (1946) to be five feet thick, to extend for several thousand feet, and to contain up to 60 percent i ilmenite and some sulfides. During the present study numerous stained ; ii zones with a maximum estimated thickness of 20 feet were visible in the gabbro of the south wall above the glacier. All had similar orienta- ' tion and were visible for thousands of feet. Their separation ranged from an estimated 30 to several hundred feet. A bergschrund was cros sed to reach three shear zones (fig. C-32). The others were more dif- 10- ficul^t to access because of steep rock, or were inaccessible because _/ of hazardous terrain and intermittent ice and rock fall. The most heavily mineralized zone contained a one- to two-foot thick vein of pyrrhotite, visible chalcopyrite and small amounts of ilmenite. Three 14 chiji samples of the vein at locations about 30 feet apart (7S011A, 7S012 and 7S013) contained up to 980 ppm copper, 3,000 ppm nickel, 0.70 ppm platinum and 300 ppm cobalt, while samples of the other two zones gave lower values (table C-26b). These iron-stained zones are similar in orientation, extent and composition to those described on the north wall of the South Crillon Glacier located Ih miles to the south. This suggests that larger stained zones in the intervening rocks may contain similar mineralization. However, access to these would be difficult. 22 23 Table C-26b near here These exposures also lend credence to the extension of Brady Glacier- 25- type mineralization to the north end of the Crillon-LaPerouse stock. 0106 =:::-ls-«^v : "OF OL 0% Cwv^^o a^o.^t»C g>^».^ OS/ ^' f t' r^ I'v^'viiT I oi 001 o l"?>i"»i -.'M a (UU) 8|duuog » c* sispuv 9-1267 Additional mineralized occurrences The remaining occurrences in the Crillon-LaPerouse stock area are described in table C-27, and their locations are shown on plate III. Table C-27 near here 5 i I Numerous stained or mineralized localities were briefly noted or des- i j cribed by persons who have been in the area but which were not neces- ! i sarily visited (see province introduction) are reported to occur, mostly j i on the west side of the stock, at several localities near where stock ; 10 contacts are exposed. They are reported to contain ilmenite, magnetite, copper, or nickel mineralization, or to comprise prominent iron or i 12 copper-stained zones in or near contact areas. Most notable among these is a nickel-copper occurrence located on the southwest end of the ' stock (table C-27 and plate III, location 14). Investigation of several copper-stained zones in amphibolite near the north end of the stock , i 16 (locations 5, 7, 8) failed to reveal any source for the secondary ; 17 ! mineralization except for the copper, up to 200 ppm, in the amphibolite ! itself. | flWrCf Fairweather stock and vicinity ; | Moont TheA Fairweather stock is at least six miles long by 3% miles 20- i I I wide and is exposed on Mt. Fairweather from elevations of 5,000 to i| 15,000 feet. It consists of layered mafic and ultramafic rocks con- taining significant concentrations of chromium, cobalt, copper, i nickel, platinum-group metals, titanium and iron. These layered i i I rocks intrude amphibolite and mica schist. The information on this stock is from Plafker and MacKevett (1970), from close aerial C-108 Table O-27 Fairwcather province, Crillon-LaPerouse ,£ayOJT&bl. , . , occurrences not discussed in text. No. on Name of Main Source of plate III prospect commodity Location Description of deposit Mining claims Samples I/ information Remarks 5 Southwest of Cu North and south Extensive copper-stained Mono recorded. Samples of the amphi- This investiga- Investiga Mt. Wilbur sides of the malachite and azurite bolite schist in the tion. tion in the North Cril Ion zones in amphibolite vicinity of the copper area failed Glacier at an schist. Mostly on over stains contained up to to reveal a approximate hanging cliffs near the 200 ppm copper (AA source for I elevation of Crillon-LaPerouse stock" analysis) . the secondary H-> O 4,000 ft. amphibolite schist mineraliza contact. tion except the low background values (up to 200 ppm) of copper in the amphibo lite schist. 5 Southwest of Ti South side of Extensive iron-stained None recorded. A grab sample of iron- This investiga- - Mt. Wilbur North CrilJon zone on a steep mountain stained rock contained tion. Previous- Glacier at face in the gabbro stock. greater than 1% titanium, ly reported in appr. an MacKevett and elevation of others, 1971, 3,500 ft. p. 83, location no. 78. 7 North Cril Ion Cu North Crillon Copper-stained amphibo- None recorded. MacKevett and In place Glacior Glacier at an lite schist float in others, 1971, source of elevation of glacial moraine. p. 53, location copper - 2,000 ft. no. 86; Kennedy stained and Walt on, amphibolite 1946, p. 71. schist; may be location 5. Table C-27 Fairweather province, Crillon-LaPerouse favorable area, occurrences not discussed in text, cont'd. . . No. on Name of Main Source of plate III prospect commodity Location Description of deposit Mining claims Samples \/ information Remarks 8 North Crillon Cu North Crillon Malachite and azurite None recorded. This investiga In place Glacier Glacier at an secondary copper stain tion. source of elevation of on amphibolite schist copper- 800 ft. float in glacial stained moraine. Large blocks amphibolite of copper-stained may be material found for at location 5. least 1,000 ft. 9 North wall of Cu North wall of "Specimens collected by None recorded. This investiga This contact South Crillon South Crillon Goldthwaite from the tion) Kennedy could not be Glacier Glacier at the north wall of the South and Nalton, reached in gabbro stock Crillon Glacier at the 1946, p. 71» 1976 because amphibolite contact between schist MacKevett and of persis schist contact. and gabbro contain 5 to others, 1971, tent rock 6% sulfide minerals, location no. and ice fall principally pyrrhotite 80. from a and chalcopyrite." hanging (Kennedy and Ma 1 ton, glacier. 1946, p. 71.) * 10 One and one- Ti The stock contact area None recorded. Rossman, 1963a, half miles probably contains 10 to p. f42. - south of 25% ilmenite for a dis Mt. Lookout tance of several hundred feet. 11 Three and one- Ni Rossman noted rust stain- None recorded. Rossman, 1963 a, An attempt half miles ing similar to that found p. f44. was made to south of Mt. on the Yakobi Island nic reach this Lookout kel deposit at several area in 1977 places along the stock but weather contact. One of the most precluded it, outstanding of these Table C-27 -Fairweather province, Crillon-LaPerouse favorable area, occurrences not discussed in text, cont'd. Main Source of commodity Location - Description of deposit Mjning claims Samples I/ information Remarks t 11, cont. stained areas is exposed on the south wall of a small glabler 3>j miles southeast of Mt. Lookout. This contact could not be O I reached for close examina tion in 1952. 12 Northwest of Ti South side of Ilmenite-rich section of None recorded. Samples contain up to Rossman, 1963d, Mt. Marchain- Finger Glacier the Crillon-LaPerouse 2.5% ilmenite and 0.1 p. f43. ville at an elevation stock. to 1% copper, and 1- of appr. 4,300 10% lead. These are ft. spec analyses of a heavy minerals concen trate . 13 Northwest of Ti South side of Rossman sample location None recorded. Sample contains 0.1 to Rossman, Mt. Marchain- Finger Glacier at well within the Crillon- 1% copper, lead and tin, p. f44. ville an elevation of LaPerouse stock. and 1 to 10% titanium. appr. 6,000 ft. These are spec analyses of a heavy minerals concentrate. 14 Northwest of Ni, . N58°30*, W137°- Lenses of disseminated None recorded. Analysis of float from Anthony, 1977, Mt. Marchain- Cu 03' south slope nickel-bearing pyrrho- lenses contains 0.83% written com ville of unnamed 7,200 tite in diorite. nickel and 0.18% copper munication. ft. mountain Exposures are in sheer (method of analysis not south of Mt. cliff at head of known). LaPerouse. glacier which issues from Mt. LaPerouse. The largest lenses are 10 ft. wide and 5OO ft. long. Table C-27 Fairweather province, Crillon-LaPerouse favorable area, occurrences not discussed in text, cont'd. No. on Name of Main Source of plate III prospect commodity Location Description of deposit Mining claims Samples I/ information Remarks 15 Northwest of Ti, North side of Copper stain at the stock None recorded. This investiga This area Mt. Marchain- Cu unnamed glacier. contact and iron-stained tion} Rossman, was investi villa layers up to 50 ft. thick I963a, p. f43i gated during that contain from 7 to 11 MacKevett and very stormy percent ilmenite. others, 1971, weather and . p. 52, location the copper- O no. 82. stained con tact could not be Si found . 16 Northwest of - South side of Prominent iron-stained None recorded. This investiga Vertical Mt. Marchain- unnamed glacier. stock contact. tion} MacKevett cliffs and ville and others, glacial 1971, p. 72, crevasses location no. 83. may* make access dif ficult. I/ All sample values cited were obtained from semiquantitative spectrographic analysis, unless noted otherwise. 9-1267 observation, and from samples of glacial moraine taken from two sites 2 whose locations are shown in figure C-34 Much, or all, of the Figure C-34iear here i ______| morainal material clearly came from the stock. The country is too | rugged for safe helicopter landings within the boundary of the stock i I itself. The significant mineral content and analyses of Plafker's and iMacKevett's samples are given in the following quote from their work, 10 ! j previously cited: i i "The analyses indicate concentrations of titanium I (two percent) and vanadium (2,000 ppm) in the magnetite- and ilmenite-bearing two-pyroxene gabbro that are not unusual for rocks of this type. As much as 5,000 ppm chromium, 5,000 ppm copper, and u 5,000 ppm nickel are present in the richest samples of sulfide- and chromite-bearing pyroxenite and is | wehrlite, as much as 5,000 ppm chromium, and 3,000 i ppm nickel, in the chromite-bearing dunite. Note- 16 j worthy amounts of cobalt and platinum-group elements ! were also found in the ultramafic rocks and, to a 17 lesser extent, in the gabbros. The largest amounts of these elements, which were in the sheared dunite 13 . (68 APr 101 A5), totaled 200 ppm cobalt and 0.84 ppm palladium, 0.171 ppm platinum, and detectable rhodium }j ' (0.004 ppm) . 20 i Disseminated opaque minerals occur in all the float i collected from the Fairweather pluton. These minerals 21 j are mainly magnetite, ilmenite, sulfides, and chromite, which undoubtedly account for the anomalous metal content of these rocks. Combined magnetite and ilmenite ! constitute as much as 10 percent by volume of some : i gabbros. The wehrlite and pyroxenite contain up to 15 i percent sulfides with minor chromite, and some dunites » ; contain a few percent of chromite with minor sulfides. ', The sulfides identified in polished section include 25- i cubanite, chalcopyrite, pyrrhotite, and pentlandite. C-113 - Base from US.Geol. Survey 1 : 250,000 EXPLANATION Mi Fairweather 1961 _..._._._ Contact, dashed where inferred, generalized from plate I O 68APr 100 U. S. Geol. Survey float 6K059 U. S. Bur. Mines stream sample location . sediment sample location X 7K066 U.S. Bur. Mines float A Copper- stained rocks, in place sample location Assay data given in table C-26______Figure C-34 Mount Fairweather layered mafic stock, sample locations 9-1267 1 i "No chromitites or massive sulfides were found. The nickel and copper content of the highest grade rocks 2 sampled is about 0.5 percent each." | 3 | During the 1976 and 1977 field seasons the Bureau of Mines made a ! Moc^ 4 j concerted effort, to further sample the rocks of theiFairweather stock. i 5_ ! Localities from which two samples were obtained by the Bureau in 6 1976 from glacial moraine from an unnamed glacier two miles south of 7 ' Sea Otter Glacier are shown in figure^^ previously cited. Analyses 3 i are given in tableG28 . These samples contain up to 7,000 ppm copper, 9 j 1,400 ppm nickel, and 2,000 ppm chromium by semiquantitative spectro- i 10- i graphic analyses, and support values obtained by Plafker and MacKevett i n i in their 1968 investigation. 12 TableG28 near here ! Also in 1976, cobbles of pyroxenite were found on a stream bar about 150 yards above the mouth of Sea Otter Creek. Such cobbles were [ I not uncommon on the bar. They contain pentlandite and chalcopyrite, ' but were not analyzed quantitatively for copper, nickel or other 13 ' metals. Their probable source was the west side of Mount Fairweather via Sea Otter Glacier. A stream-sediment sample from the vicinity | contained 1,500 ppm chromium. ', 21 I : In 1977 the USBM made helicopter landings as close to the stock as ! was practical. No helicopter landings could be made on any part of the 23 i stock outcrop because of the extreme ruggedness and relief of the .mountain massif, although two landings were made within the mapped stock r-115 .-.,->.-* - f ojc y v Ot- oot 00^ 23 100' vD 00/7^ rH -£? ADSSV "'Vft boundary where ice and snow covered bedrock. Float from within the stock and from areas just outside the contact was obtained from four old avalanche paths containing scattered rock debris. Sites are shown ! in figureC-34, previously cited. i 5 Pyroxenite, peridotite and dunite were obtained in float from the ; west side of the mountain near the head of the glacier between Sea ! i I 7 Otter and Fairweather Glaciers from about 3,700 feet in elevation, h \ j to 3/4 mile outside of the layered stock near where copper stains on a ' nearly vertical wall of mica schist or amphibolite appeared prominent, ! 10 but could not be approached. Samples (see tableG28, previously cited) contained up to 5,000 ppm copper, 3,000 ppm chromium, 2,000 ppm nickel, 200 ppm cobalt, 1.5 ppm silver,.17 ppm platinum and .34 ppm j 13 ! palladium from this avalanche site. Most material probably came from r 14 a very high and exceedingly active ice fall to the north, just outside i ' 5~ j of the stock contact. i 16 : Just inside the contact, well above the ice fall and close to 17 I conspicuous copper stains in the vicinity of the contact, slide or 13 ; avalanche debris'consisted of gabbro. The most interesting looking 19 i specimen found, metagabbro with obvious sulfides, contained 2,00o ppm ~°~ i vanadium. 21 j It appears that one source of the ultramafic rocks which contain 22 I significant quantities of copper, chromium, nickel, cobalt, platinum 23 and palladium may be in the vicinity of the stock contact about four 1 miles a little south of west of the summit of Mount Fairweather, 25 probably above 4,000 feet in elevation. These rocks may extend to C-117 9-1267 jthe north as well since they are found in the moraine on Sea Otter j JGlacier. i No ultramafics were found among avalanche debris at the site shown on the south side of the stock on the north side of Fairweather 5 \ Glacier. Most rocks were either gabbros, amphibolite or mica schist. An occasional fragment with secondary copper stain was found. Ultramafic rocks were again found 2h miles south and a little east of the Mount Fairweather summit at about 6,200 feet in a basin near the head of Fairweather Glacier. Here, although most rocks were 10- of the gabbro clan, dunite, pyroxenite, and peridotite were also found. I Analyses of two samples gave values in ppm up to 6,400 for i copper, 5,000 for chromium, 2,000 for nickel, 300 for cobalt, .07 for j platinum, .28 for palladium, and 1.7 ppm for gold. i i i Clearly, at least two localities in or near the Fairweather j 15 stock contain ultramafic rocks with significant values in copper, ; nickel, chromium, cobalt and platinum-group metals. [ 7 ; Considering this limited exploration, significant metal minerali- s < zation has been found. Technical mountaineers would be able to 's ; examine portions of the stock in spite of the inhospitable terrain. 20 The mafic and ultramafic rocks of this stock are an excellent environ- i 21 ment for the further discovery of magmatic segregation-type deposits ~i \ containing copper, nickel, chromium, cobalt, platinum, titanium, and 23 ; iron. To be economically viable, deposits discovered here will have to 2-» ; be high enough in grade and tonnage to overcome the difficulties of C-118 9-1267 mining in such a remote, rugged and inhospitable environment. Astrolabe-DeLangle stock The Astrolabe-DeLangle layered gabbro stock is exposed for a distance of about eight miles along the coast between Dixon Harbor and Palma Bay in the Fairweather province. Geophysical information isuggests that it may be considerably larger than its maximum outcrop dimensions of two by eight miles would suggest. Concentrations of magnetite, ilmenite and some sulfides occur within this body. In the early 1900's, F. E. and C. W. Wright discovered the Astrolabe-DeLangle stock in the course of geologic mapping in the n Ii area. Field investigations by D. L. Rossman in 1946 and 1956 consti- 12 I tute the first detailed study of the stock. | iI DeLangle Mountain magnetite prospect !' i A group of nine claims was staked in 1955 on a magnetite prospect i i i within the stock on DeLangle Mountain. , | | | On DeLangle Mountain the gabbro intrudes hornblende schist and ; i gneiss probably formed from a greenstone-slate unit of Mesozoic age i ; (Rossman, 1963 a) The latter unit is unconformably overlain by j sedimentary and volcanic rocks of Tertiary age. An exposed thickness | of 2,000 feet of the layered rock of the intrusive displays synformal 21 i structure. The exposure includes neither the top nor bottom contact i of the sequence. Layers are delineated by changes in composition and i texture of the constituent minerals. A cumulus process is considered i i the origin of the layering. The intruded bedded rocks are largely 25 C-119 jrecrystallized within the gradational contact zone adjacent to the intrusive. Hornblende-plagioclase pegmatites occur in the gabbro near the contact and contain local concentrations of titaniferous magnetite. Field investigation revealed no sign of claim markings or development work on DeLangle Mountain. On the southern spur of the !summit ridge at an elevation of 2,700 feet a severe magnetic distur- ibance was noted. At this location a sub-horizontal hornblende- i 'plagioclase permatite body approximately 100 feet wide and 20 feet i I thick crops out discontinuously for a length of about 1,000 feet I 10 i within the gabbro. The hornblende occurs in anhedral to euhedral 1 crystals up to one foot in length. Magnetite occurs throughout the 12 pegmatite in inclusions with a length of five mm or less. Concentra- | 13 | tions of magnetite occur near the larger hornblende and plagioclase i i i crystals. Four spaced-chip samples. (6K046-49), ranging in length | 15 ' from 18 to 40 feet, were taken of outcrops of this pegmatite structure .] \ j Assay results of these samples reveal that each contains ten percent : iron and greater than one percent titanium, while copper values range from 150 ppm to 500 ppm. FigureC-35shows the sample locations. ; Titanium was run by spec which has a one percent upper detection limit. 1 ; Actual titanium values may be much greater. 21 FigureC-35near here C-120 136° 55' I36°50' 25 Leo Mark Anthony sample location Rossman sample locations EXPLANATION Layertd gabfaro (Lower Rrieozoic?or Pre cambrian?) Includes some Ter tiary acid intrusives on D«- Langle Mountain. Mainly hornblende gneiss and schist, and biotite schist,and semischist (Lower Baleozoic ? or Precambrian?) with some Tertiary ocid intrusives In cludes areas of cover. 58* 20' Contact, dashed where con- cealed,qeneralized from platel Fault 6K050 Location of samples collected ( during the present investigation Sugar Loaf Area of samples collected Island O by other investigators Contour interval I mi. 100 ft. km. 0 .5 I Base from U.S. Geol. Survey h63,360 Ml Fairweather B-3 1961 Figure C-35 Astrolabe-DeLangle stock, DeLangle Mountain magne tite prospect, sample locations C-121 9-1267 A sample (6K050) was obtained from an isolated outcrop or ! possibly float in the south-facing cirque below the summit. Assay i ! results of this 22-foot long spaced-chip sample include 15 percent ; j iron, greater than one percent titanium/ and 150 ppm copper. j Other mineralization in vicinity ' I Rossman sampled layers in the gabbro containing concentrations of j ilmenite and titanium-bearing magnetite on the southern end of Astrolabe Peninsula. These mineralized layers crop out near the top ! of the headland between 1,100 and 2/000 feet in elevation/ and represent 10 a stratigraphic thickness of abut 1,000 feet. Recrystallized rocks j probably representing a roof pendant or xenolith also crop out near ' the top of the peninsula. Some titaniferous magnetite was found in j ; 13 j the contact zone of the stock. His samples contained from one percent ; ! i ii to 22 percent magnetite, and from two percent to 12.5 percent ilmenite. ii i Not all the samples were analyzed for their ilmenite content. The I analysis of two samples of magnetite gave 10.69 percent and 8.5 percent iTiC>2 by weight. Sample locations are shown in figure C-3s / previously ' i cited. i * ; Leo Mark Anthony (written communication, 1977) furnished informa- , tion regarding another zone containing iron and titanium about a mile ' south of the summit of DeLangle Mountain on the southeastern slope ! | where he reported bands and disseminations of magnetite and ilmenite i in altered diorite in a 1,500 by 4,000-foot zone having an estimated ; iron content of about 10 percent. The best showing was considered a 225-foot long band two feet wide reportedly assaying about 64 percent C-122 9-1267 iron, 20 percent titanium and 0.28 percent nickel (see figure C-36, previously cited for location). Remainder of province About half a dozen showings of base metal mineralization, stained zones, and geochemical anomalies are reported within the Fairweather i i province which do not appear to be near enough, to any of the gabbroid ij j stocks discussed to have been associated with them. They include two i zones in amphibolite containing secondary copper minerals which were !I visited (20 and 21) and are similar to the zones described to the I north of the Crillon-LaPerouse stock. These are to the south of it andj i : j several miles away. Another locality (17) which sounded particularly j I j interesting could not be found on the basis of the description of its ; position. Information concerning these showings is given in table < | I u I C-29, and their locations shown on plate III. i 15 Table C-29 near here 22 C-123 Table C-29. Remainder of Fairweather province, occurrences not discussed in text . No. on Name of Main Source of plate III prospect commodity Location Description of deposit Mining claims information Remarks 4 Helicopter Mo On a sharp arete In 1976 a landing was made None recorded. This investiga Pilot's 3/4 mile south at a precarious spot to tion. Molybdenum of Mt. Orville at examine a prominent iron- the 6,000 ft. stained zone. The pilot elevation. produced a rock fragment that contained either O molybdenum or graphite. I High winds forced an immediate retreat and the rock fragment was lost. Snow conditions precluded a landing in 1977. 7 North Or i lion (See Crillon- LaPerouse area of high mineral potential) Glacier 8 North Crillon (See Crillon- I. aPerouse area of high mineral potential) Glacier J7 North side of Ni, NSS'M? 1 , W137°- Disseminated nickel-boar- None recorded. Analysis indicates the Anthony, 1977, Search for in Desolation Cu 33' ing pyrrhotite, pyrite average grade is 0.59% written conunu- 1977 during Glacier and chalcopyrite in gab- nickel, 0.62% copper, nication. stormy weath bro diabase dine with an 0.01 oz. gold/ton and er but not average width of 5-6 ft. an estimated 2-5% titani found . and exposed for about um (method of analysis 200 ft. unknown) . 18 Desolation Northeast side Conspicuous iron-stained None recorded. A random composite chip This investiga- Local stream Valley of Desolation area in hornblende gneiss sample taken over much tion. and slide Valley between containing disseminated of the stained area con float also Desolation and pyrrhotite; 40 ft. by tained no significant searched. Lituya Glaciers. 150 ft. zone locally. metal values. No signifi Elevation 900 Others in distance. cant mineral ft. ization was found . Table C-29. Remainder of Fairweather province,occurrences not discussed in text, continued. No. on Name of Main Source of plate III prospect commodity Location Description of deposit Mining claims Samples information Remarks 19 Southwest of Cu From an eleva- Follow-up of USGS float None recorded. Sample across sulfide This investiga- A more com- Cascade tion of 3,400- geocheraical sample con- mineralized seam 10 ft. tion. plete inves Glacier 3,600 ft. taining 1,000 ppm copper long and up to 0.4 ft. tigation of southwest of revealed large area of wide contained 800 ppm this area Cascade Glacier, iron-stain in amphibo- ' copper, 0.15 ppm gold is warranted. lite schist that contain (all AA analysis) , and O I ed up to 240 ppm copper. 7 ppm silver. 20 Palma River Cu North side of Large malachite and azu- None recorded. Samples across amphibo This investiga- Investiga copper stain the Palma rite stain on a short, lite schist near copper tion, tion of the River where it overhanging cliff in stain contained up to area failed enters the sea. amphibolite schist. 220 ppm copper (AA to reveal a analysis) . source for the secondary copper mineralization except for the low back ground values (up to 220 ppm) of copper in the amphi bolite schist. 21 Triangulation Cu North of Torch A prominent malachite None recorded A sample across the This investi- Investigation Station Garnet Bay just above and azurite-stained over copper-stained zone tion. of the area sea level. hanging seacliff of gray- contained 230 ppm cop failed to re wacke and schist. Copper- per (AA analysis) . veal a source stained area about 10 ft. for the secon by 5 ft. dary copper mineralization except for the low background values (up to 230 ppm) of copper in the host rock. Table C-29. Remainder of Fairweather province,occurrences not discussed in text, continued* No. on Main Source of plate III commodity Location Description of deposit Mining claims information Remarks 22 Brady Glacier Au Extremely fine-grained (tone recorded. A sample from the western HacKevett, 1971, "Mining acti- outwash gold occurs in the out- most section of the fan p. 57, location vity during wash fan at the terminus contained 0.15 ppm Au no. 55} Rossman, the early part of the Brady Glacier. (AAS analysis). A sample 1963a, p. 50-51; of the century A total of 10 stream collected near the mid this investiga probably sediment samples were point of the fan's peri tion. resulted in taken along the 3-mile meter contained 0.7 ppm the production long permieter of the Ag. A sample from the of a small NJ OY' fan. eastern edge of the fan quantity of contained 200 ppm Cu, gold." Ross 300 ppm Cr, 70 ppm Ni man, 1963a. and 30 ppm Co, indicat ing an ultraroafic proven ance of the detritus. \J All sample values cited were obtained from semiquantitative spectrographic analysis, unless otherwise noted. 9-1267 North Geikie sub-province Margerie Glacier ^favorable area The Margerie Glacier favorable area is up to four miles wide and extends from the south side of Johns Hopkins Inlet to c s the Margerie Glacier, a distance of 17 miles. Plate III shows the location of the area and figure C-2 shows the location of the most important mineral occurrences in it. In 1977 Mary Ann Parke was employed by the Bureau of Mines to do her geologic master's thesis project on the portion of the Geikie pro vince between John Hopkins Inlet and Margerie Glacier. She did much of! ',0 i the field work used in this report on the Margerie Glacier deposit, "Tarr Inlet Knob" prospect, 3,087 nunatak, and on other less important pros- j pects; contributed to field work on the Orange Point deposit, and mapped 13 I I i the region in detail along the coast and to a much lesser extent at i j ] 15 i higher elevations. Information from rough drafts of her master's the- ', i j \ sis titled "Geology and Mineral Resource Potential of the Margerie ; 16 I Glacier Area, Southeast Alaska" is used when the above deposits or ! prospects are discussed. In conjunction with an evaluation of Ms. | ; Parke's thesis project, Dr. lan Lange of the University of Montana, an i 20 expert on sulfide ore deposits, consulted for the Bureau on the Orange j | Point and Margerie Glacier deposits, and on the Tarr Inlet knob ' I 21 prospect. 22 23 \ 24 25 C-127 The only recorded claims in the area are the six covering the Margerie Glacier prospect located in I960, and two claims located 1,500 feet from tidewater and two miles southeast of the Margerie Glacier located in 1944. These are no longer active. Prospecting in much of the area near tideline can be accomplished from a boat and on foot; however, prospecting the high alpine areas will require a helicopter and, in extreme cases, the use of mountaineering equipment. The area consists of a Permian metamorphosed marine stratigraphic section of intermixed volcanics, shales and limestones that are intruded by Tertiary and Cretaceous granitics. This section trends north-northwest with a steep southwest dip. Graded bedding and rip-up clasts found in this stratigraphic section indicate the top of the stratigraphic section is to the east. The granitics tend to be elongate, parallel to the bedding, and contain conformable zenoliths of the marine section. The area is cut by numerous faults and fracture systems (Parke, 1978). Numerous and extensive iron-stained zones are found throughout the area. Two important deposits have been discovered by very limited pros pecting in the area: the Orange Point volcanogenic zinc-copper deposit and the Margerie Glacier porphyry copper-tungsten deposit. Both contain significant resources and both have excellent potential. The area also contains numerous showings of important ore metal mineralization, the most significant of which are a 24 ppm gold anomaly from a limited drainage; numerous showings of sulfides associated 0128 9-1267 with volcanics that may be indications of volcanogenic type mineraliza- i I ition; copper, zinc, lead, silver and gold mineralization located along i |fractures at the Tarr Inlet knob; and an area containing significant \ i rock geochemical and float molybdenum anomalies. The important deposits . and prospects currently known were indicated by iron-staining. Exten sive and numerous iron-stained zones found throughout the area should provide a guide to prospecting. The Orange Point deposit and the above mineralization were recognized by the Bureau of Mines in the course of i this study. ! Orange Point zinc-copper deposit Introduction The newly discovered Orange Point zinc-copper deposit is located in a metamorphosed Permian stratigraphic section of mixed volcanic and sedimentary rocks on the north side of Johns Hopkins Inlet and forms a C-H9 9-1267 1 spectacular iron-stained zone that is visible for miles across the i i 2 | inlet. Figure C-2 shows the deposit location. This area was examined by Reed during the 1930's (Reed, 1938) and by a U.S. Geological Survey team headed by MacKevett in 1966, plate III, location (MacKevett s_ ! and others, 1971, location 64). No claims are located in the area. 6 ; The massive sulfide mineralization in the area was first discovered ! 7 i| or recognized by a Bureau of Mines' crew late in the summer of 1976. a Follow-up work in 1977 revealed various zones of zinc-copper massive 9 | sulfide mineralization located from sea level (Hill #1) to a 500-foot i 10 elevation (Hill #3) over a horizontal distance of 2,100 feet, and n indicated a volcanogenic-type origin for the deposit. Figure C-36 is 12 i a sample location-geology map of the area. I 13 i u i Figure C-36 near here 15 ' i Because some volcanogenic-type deposits have proven to be both I 16 j ' j large and high-grade and, in addition, tend to reoccur and cluster in 17 ! ' a given strati graphic unit, this type of deposit has become an impor- '8 tant mineral exploration target. 19 i ' The massive sulfide mineralization found at Orange Point is con- i 21 ; | formably hosted in andesite and volcanoclastic rock, which is part of 22 ; ; a large northwest-trending and steeply-dipping metamorphosed sedimentary 0130 EXPLANATION EXPLANATION Massive sulfide zone Surficol cover or andesite with sul- '7:1 Diorite with some metavolcanic or meta- fides, containing from .-'-/ J sedimentary rocks (Cretaceous) 0.05 to 1.2 % copper Metavolcanics with some metasedimentary or zinc rocks, often highly iron-stained. Partially as Massive sulfide zone, similated by diorite and in some areas pre dominantly diorite (Permian) containing 1.2% or greater copper or zinc. ^ Massive sulfide zone or andesite with sul- Five-foot long samples W fides, containing greater than 0.05% copper contain up to 5.2% ^ or zinc copper and 19.0% zinc. Iron-stained zone that sampling indicates contains no metal values Post-mineralization dike o ; i Vertical contact or probable fault -- Contact, dashed where concealed Probable vertical fault 78 i. Probable fault, showing dip 7M08I \ Ch»p sample location, length to scale 7S092 Chip samPle 7S029F-I Assay data given in tables C-30 through C-33 7S029D-A 75028 D 7S028A-C 0 200 400 75029 E Contour interval H-M feel 100 feet meters Note: Additional 60 120 locations shown in figui Base from US.6.S 163,360 Geology mapped by J. Still. M. Parke Mt Fair weather D-3,0-4, 1961 1977 Rgure C-36 Orange Point zinc-copper deposit, sample locations and volcanic marine stratigraphic sequence whose top is to the east. In places the stratigraphic section is largely assimilated by diorite that forms vague gradational contacts with the rock hosting the sulfides. Relic textures in the assimilated rocks are conformable relative to the rest of the stratigraphic section. The sulfide bodies are in the form of elongate lenticular massive sulfide zones up to 80 feet wide (Hill #2) or narrow, intermittent elongate tabular (blanket) bodies up to 560 feet long (Hill #3). These form sharp unaltered contacts with the volcanics but within the zones themselves there is a gradation from andesite with disseminated sulfides to massive sulfides. The sulfides are pyrite, pyrrhotite, sphalerite and chalcopyrite. Very fine conformable relic sedimentary layering has been preserved in the sulfides but most of the sulfides are recrystallized, either from the thermal effects of regional metamorphism or nearby intrusives, and original textures have been destroyed. The sulfide zones also contain, in varying amounts, andesine, oligoclase, chlorite, sericite, muscovite, calcite, quartz, epidote and rarely small amounts of hornblende-actinolite and biotite. Zinc (up to 19 percent) and copper (up to 5.2 percent) are the most important economic constituents of the sulfide zones with gold and silver important by-products. The highest copper values are found in the lowermost stratigraphic horizon and the highest zinc values in the highest horizon of the Hill #2 mineralized zone. Silver-gold ratios generally range from 45 to 114. Analysis for other elements indicates the following: barium is common in amounts over h percent, lead is C-132 occasionally found in amounts up to 1,600 ppm, molybdenum is commonly found in amounts from 5 to 100 ppm, cadmium is found in a small portion of the samples in amounts from 20 to 500 ppm, strontium is found in most of the samples in amounts from 100 to 500 ppm, as are vanadium and cobalt in amounts from 10 to 150 ppm. Absent in all Orange Point samp les were arsenic, antimony, bismuth, tin and tungsten. These metals are often associated with hydro-thermal or contact-type deposits. Two or more of the latter five metals are associated with each known hydro-thermal or contact-type deposit found in the immediate area (Reid Inlet gold veins, Margerie Glacier porphyry or vein deposits, massive chalcopyrite contact-type deposits, and Tarr Inlet knob vein and altered zone deposits. The above description, in general, conforms to published descrip tions (Large, 1977, p. 549; Hutchison, 1973, p. 1228; Lusk, 1975, p. 1070; Graf, 1977, p. 527; and Koo, 1975, p. 48) of volcanogenic-type massive sulfide deposits. Also, this deposit is somewhat similar to the Big Sore (Greens Creek) deposit, considered volcanogenic, and currently being drilled about 100 miles to the southeast on Admiralty Island. In particular, the following factors suggest a volcanogenic origin for this deposit: geologic setting, in a thick sequence of intermediate volcanics; consistent simple sulfide mineralogy of pyrite, pyrrhotite, sphalerite and chalcopyrite; presence of zinc, copper, silver and gold as the only economic minerals and their relative proportions; presence of barium along with occasional lead and the absence of arsenic, antimony, bismuth, tin and tungsten; and. the size, shape, C-133 9-1267 I zonation and sharp contacts with the volcanic host of the massive sul- I fide zones. It can be interpreted that this deposit was formed at the -time 10 14 1.5 13 23 C-134 9-1267 | volcanic rocks in the stratigraphic section were being extruded into a j marine environment as the result of hydrothermal fluids leaching metals out of volcanic rocks and forming chemical precipitates in sea water. i The Orange Point massive sulfide bodies generally conform to Hutchinson's i volcanogenic-type I classification in terms of host rock, mineralogy, I i zonation and ore metals present; however, no obvious alternation vent i i for the bodies was observed (Hutchinson, 1973, p. 1225). The narrow, !I tabular nature (blanket) and sharp contacts of the Hill #3 body may i j indicate that it is of distal origin, though the mineralogy and ore i j| metals present do not necessarily conform to Large's distal classifica-j JO- j tion (Large, 1977). The study of this deposit was very limited and additional work is necessary to determine its nature. Description of mineralized zones and resources j The zinc-copper mineralized zones of this prospect are most easily! discussed if the area is divided into three prominent hills: -_ i Hill #1, elevation 120 feet; Hill #2, elevation 290 feet (by far the most important); and Hill #3, elevation 490 feet. Figure C-36, pre viously cited, is a geologic and sample map of the area, and figure C-37 is an aerial photograph showing the terrain and detailed sample i Figure C-37 near here 2\ i ______22 j locations for Hills #1 and #2 for samples visible at the photograph :s angle. Tables C-30 to C-33 give the Tables C-30 to C-33 near here C-135 7S041 C,B,A Location of grouped sam ple, showing relative j position of sample com- j ponents. * Photograph shows metamorphosed volcanic rocks ? with some sedimentary rocks that are intruded ; and assimilated by diorite, in some areas pre- I dominant!y diorite. Some of the iron-stained > volcanic rock, indicated by the darker shade, contains massive sulfide deposits. i:£ itJ Figure c-3? Oblique aerial photograph of the Orange Point zinc-copper deposit, showing the southwest side of Hill ' no. 1 and no. 2 mineralized zones and sample locations. Table C-2>0 Assay data^Ov-Qv^*. Po,'** < #£" -z.*«- Analysis Distance in ft PPiRTS PER hTLLION Sample Length from start of A, ft Sample Type Feet (m) - sample line Cu Au Descition »-*' ! A<>* / n I -* < 75031 A r.o 33,0* w;4*U \Si*e+ 7SP3I 6 - ID 2s;coo /^a^ AO SO f1 10-15- 7503 1C 000 1/0,000 SO 3.15" // . 7^^ t.lpjo»\A AU.J UJ /. 5" A5- ^f 7.3 2V.7-32 7 73- 38 330 /O 10 A 5" 330 ^oo £-.0 170 300 ./O 7SOJZB /TOO $20 5,0 3-700 1 U,l/\4U ol L 060 (->va< 5.0 Ifoo 1 '^f- noo ./O .O.l ll.aw 500 6*0 750306 76-81 3100 L -7 5.0 $00 ./o 11.0 /O .-'7 £030 A fo.o 3.0 50(8 /o N H. 00 c u. C.-s H 0 \0 Vn u. 8 O 3: o o vt <£ £ 8 S CO 0 § A; -a AJ u 'NJ fO C, rJ , rvi OJ o2 5 ^ \n In o. o to" o oa (O U to *no tn t cq O UJ Q CQ o JO r- n- r- C-138 Table 0-3c> Assay Analysis Distance in ft PARTS PER MILL! Sample Length rom start of 'A. A SPtC, Sample Type Feet (m) . sample line A Descition VIA JLSL 2.000 30 30 7S038C 730O 20 /O /OOD WOO o GO "7502 'iD Abif. r.o vO -7 L£. 30CD ./O 7502*1 ft A£ 5700 /O O.SSy^UjO.ttl %7^ .Alt^il.^! cU.' 1503BD /r l^l.ooc ,50 ./O 750?^ 730 "000 .25" A2- lo 70.r-74.0 pc«y yf i c PA 76,0-77.8 10,000 W.OOO ID. -r ^ Table C -3 / Assay data^O*-«^^e- Po.'^v A«pas.;4-^H/ll * 3"mtVev«U'z^ "z^e. ', ' ^Analysis Distance in ft PftRTS P6R hULI ow Sample Length from start of A. A. A.F\. A,h, SPC-C. Sample Type Feet (m) sample line £lc "2 v\ AK fx- Desciption . rl^'t*. SA"WAI^- li'^xCS, li'itfA q lr»vi^ VVo^-t*^ 4t» Sowfu AM S*« *vwAAi <2. I/K^V i^»»T *»' C*^ "ZtiMff ftWwtT* t - 1 4 / . ( _ / . , PI o . a\A(i £ix\i*»^l^«f P*t y-/T«!. D H irt»Uoi 1 1 c. t\*to\c*>r>t\n'ie. *t.O 75035" A 6. t Uv P , 0 - f .0 3 to ?5«>i r e? ^,r f h-RS- (<1CO 560 Mt-os;) 1 -7SOSV A 4,D f ' . > 0-6.0 ^ob tfCO JO 1 ?3o3^ g 4,0 t.^i?.o f^oO */Ojd ,30 ^o . 75034 A ^D O-3'.O ftsOCC) (c5£>0 ,/0 w ' ?So^ & s;o £.O-lot Q tffOOD I'loO .^o *D f \O.o-H>,& Nut- i d4 |/ m Q*t pt,£>tonUI<. |U^^ S«vU<>- <» S "^SoStC 1 ft^J '"^ ^So^f ^ c U.'P V.r 4,740 .3o /O 75o*iE 4,0 4, ZOO n\ooo .30 /O . ;,5" "7So1l A cU;p 0.6 Or 0.4 //,000 20,00) 1$ 76o O4t\/ v n;«4 val.^A/o^ V -tU, ore /i ,-u o{ M/ 1/43 ""^Obfc 10' 35" cU/p pr 25. 9 /O Nit^s) M . , t 1 i' -' i ' 1 - fable C-2i2. Assay data^C?v*w Analysis Distance in -ft PCS Sample Length from start of A. A i Sample Type Feet (m) sample line A Descition 14 7 5037 A .20 »;1Vr 10 Vso ./O 9 M^3 " 7 .o 4,0 75037 E £ Kl 6.0 / o.io 30 M**>|'U«- ** py'*** * A 0-1 llfi.^ j> Tablet -33 Assay datcuC?v-A*^<. P»I'A* T«V» ..KJ'VO (#30 C C 1 T 1 m'l'V -fluuL . 750V-7 30 30D AJ &- i r $0 7 75o7o -7 d M4 IHI O. 3 6COO Z 75" B D 1.0 VOOQ 3500 .20 I'f 32,^? WOO oti V 3,0 130 ! -'75063 /r /O A/ X5" l,S"'cU» /5T N 30 q.i 90 -7S067 6,0 50 110 fr.o ZOO 35- L. 7S065-A ZD M JLkjL^ "75064 /O /O 1.1 M 2'cU/p 20 /O M 7/108 2*5. ? AJ6C5) hi analytical results for the prospect. First the less significant minerali zed zones are discussed briefly followed by a detailed discussion of the main Hill #2 mineralized zones. The Hill #3 zinc-copper mineralized zone extends intermittently from an elevation of 290 feet to 485 feet for 560 feet along strike. To the north it disappears under cover and does not reappear in outcrops along strike a few hundred feet north, and to the south it disappears under cover that extends to the ocean. This zone's "best ore metal mineralization" as indicated by sampling (samples 7S036A and B) is 1.6 percent copper, 0.4 percent zinc/ traces of gold, and 0.6 ounces of silver per ton for at least a 10-foot width (six additional feet of the zone were not sampled). The zinc-copper mineralization of Hill #1 and on the south side of Hill #2 below an elevation of 200 feet is mostly scattered in small, low-grade lenses and is not nearly as high-grade or continuous as that found on Hill #3 or on the main mineralized zone of Hill #2. The main Hill #2 zinc-copper mineralized zone starts at an abrupt truncation at an elevation of 200 feet on the south side of Hill #2, extends over the top of that hill to an elevation of 290 feet and down the north side of the hill to an elevation of 195 feet, where it disappears under cover. This zone does not reappear in outcrops 800 feet further north. On top of Hill #2, most of the zone is under cover but for a few outcrops. The steeply dipping sequence of marine sediments and volcanics in the region has a trend approximately parallel to the mineralized zone. The massive sulfide body nas a wedge-shaped exposure, 50 feet C--143 across its upper portion (elevation 290 feet) and 80 feet across the lower portion (elevation 200 feet), indicating increasing zone width with depth. For the purpose of resource calculations, the main Hill #2 mineralized zone can be inferred to be roughly in the shape of a rectangular prism with dimensions established from the following assump tions. A strike length of 400 feet is based on the zone being continuous between north and south outcrops which is strongly indicated by the comparative size, shape, composition and orientation of these outcrops. A depth of 300 feet is based on the known 100 feet of depth established by relief and an additional depth inferred from ^ the 400-foot strike length, or 200 feet. This assumption is supported by the disap pearance of the whole mineralized zone under cover to the north and complicated by its abrupt truncation to the south by a probably vertical fault. The average width of 65 feet is based on an average between the (50 + 85) top and bottom width, ^ 3 J~* Using an estimated tonnage factor of 9.5 cubic feet per ton and the above established dimensions of 400 feet by 65 feet by 300 feet, the Hill #2 mineralized zone contains 800,000 inferred tons. The Hill #2 main mineralized zone was sampled at four locations: across the southern end of the zone (7S028-29, 200-foot elevation); the northern end of the zone (7S030-32, 195-foot elevation) on the top of the zone near its south end (7S103, elevation 258 feet), and on the top of the zone 60 feet further north (7S040-41, elevation 286 feet). The sample lines on top of the zone crossed only part of the mineralized body. C-144 These sample lines indicate portions of the Hill #2 zone from 15 to 25 feet wide, that average eight times more copper and zinc than most of the remainder of the samples. These high-grade sections are indicated by portions of the sample lines at the northwest (7S031A-D), southeast (7S028A-C, 7S029E) and eastern side (7S103A-F) of the hill, see inset figure C36 and table G-30 . There is insufficient data to -establish shape or extent of these high-grade sections within the larger Hill #2 zone, but they are probably in the shape of elongate lenses and represent about 1/3 of the volume of the whole Hill #2 zone, or 270 thousand tons. Values for individual five-foot long samples of the 15- to 25-foot wide high- grade portions range up to 5.2 percent copper, 19 percent zinc, 0.1 ounces gold per ton and two ounces of silver per ton. The estimated average grade for 1/3 of the Hill #2 mineralized zone or an inferred 270 thousand tons is 2.7 percent copper, 5.2 percent zinc, 0.03 ounces gold per ton, and one ounce silver per ton or $75 per ton at February 1978 EMJ prices. The lower grade remainder of the Hill #2 mineralized zone, 530 thousand inferred tons, has an estimated average grade of 0.4 percent copper, 0.3 percent zinc, 0.006 ounces gold per ton, and 0.35 ounces silver per ton or $9 per ton. The main Hill #2 zone has an inferred gross in place value of $20 to $25 million and the higher-grade portions of it may be exploitable by a small owner-operator type operation. This value would be much larger if the Hill #2 mineralization is found to extend to depth and under cover to the north. No resource value has been attached to Hills C-145 #1 and #3 because of limited sampling; however, potential does exist in these areas for additional tonnage. !: Limits of this investigation and work necessary to further delineate this deposit i Due to time constraints, size and rugged topography of the "Orange Point" area investigation of iron-stained zones, mapping, sampling and geophysical work were of very limited detail. The following work would be necessary to further delineate this deposit: 1) Detailed magnetometer 9 work in the area of surficial cover to the north of Hill #2 may help ! delineate the subsurface behavior of the mineralized zones. Limited magnetometer work during this study indicated a 500 gamma anomaly at one location across the Hill #2 mineralized zone. 2) Diamond drilling and 13 shallow surface trenches would delineate the Hill #2 mineralized zone between north-south outcrops, at depth and to the north where it is under cover. 3) To date only the most prominent iron stained outcrops in the area have been examined. The numerous remaining stained zones 'should be examined and sampled in detail. Most of these are on the sea cliffs in the southeast part of the area and will require the use of technical rock climbing equipment. The structural features of the area should be mapped in detail. Summary Limited investigation of the Orange Point area has revealed one mineralized zone (Hill #2 main mineralized zone) with an inferred gross in place value of $20 to $25 million and that because of its indicated C-146 volca6njgenic deposit type, high grades of metal values (5-foot width containing up to 19 percent zinc and 5.2 percent copper) and apparent increasing width with depth may prove with more detailed exploration to be significantly larger. The Orange Point area has not been explored in detail and additional, more thorough exploration may reveal additional important deposits. suicide. Other potential volcanogenic^showings The following showings of sulfide mineralization in volcanic rock may be indications of more extensive volcanogenic-type mineralization. 3,087 nunatak Massive sulfide lenses up to two feet wide and 6 feet long, similar in appearance to those at Orange-Point, are located- . - . ..-._-.- in volcanic rock near a 3,087 nunatak about four miles northwest of and 7,500 feet stratigraphically above the Orange point deposit (Parke, 1978). The location is shown on plate III. No analyses were performed. South side of Johns Hopkins Inlet In a region of mixed diorite and metamorphosed sedimentary and volcanic rocks, a small lens of pyrrhotite was found hosted in iron-stained volcanic rock. A 0.2-foot thick sample (7S044) across the lens contained 1,300 ppm copper, 30 ppm molybdenum, 1.5 ppm silver and T. 05 ppm gold. FigureG-38 shows the location. Figure G38near here C-147 Base from U.S. Geol. Survey , I 63, 360 Mt. Fairweather 0-3, 1961 and Ml Fairweather 0--4, 1961 EXPLANATION Location of samples containing anomalous molybdenum 10-30 ppm Mo. Greater than 30 ppm Mo In - place rock sample In - place rock sample A Rock float sample A Rock float sample -|70 55| Sample location and analysis, reporting molybdenum and copper, respectively, ' * in ppm. Shown for sample with at least 50 ppm Mo. Qy 7MI2I Location of stream sediment sample containing 21 ppm gold and 7ppm Ag. X 7S044 Location of rock sample of sulfides in volcanic rock , showing type of sample (In-place) Figure C-38 Johns Hopkins Inlet, showing molybdenum anomaly area, gold anomaly location and location of samples of sulfides in volcanic rock C-148 Two float samples (7S096 and 7S0101) collected on the south side of Johns Hopkins Inlet/ probably originating in the immediate area and consisting of volcanic rock, chert and sulfides, contained up to 4/600 ppm copper, 120 ppm zinc/ seven ppm silver, and 0.05 ppm gold. Figure shows the sample locations. MaoKievett and others (1971) describe an altered zone in granitic rock on the south side of Johns Hopkins Inlet/ plate III, location 29 . His grab sample from the zone contained 1,500 ppm copper and 30 ppm molybdenum. Brief reconnaissance of this area during the present study indicates this altered zone may, in fact, be remnants of mineralized volcanic rock similar to those found near the Orange Point deposit. In summary/ there are numerous instances of sulfides associated with volcanic rock that may be indications of volcanogenic mineralization. The extensive section of volcanic rocks that extends from the Margerie Glacier to south of Johns Hopkins Inlet, particularly the Orange Point horizon, should be investigated in detail for such mineralization. Margerie Glacier porphyry*copper deposit Introduction The Margerie Glacier porphyry-copper deposit contains important copper resources and has excellent potential. It is located in rugged terrain on the south side of the Margerie Glacier and extends from an elevation of 1,100 feet to about 3,200 feet. The deposit is not reasonably accessible by foot from tidewater because of badly crevassed glaciers and steep mountain cliffs. Access is gained by several natural helipads on the deposit. Figures G-2 andG-39 show the prospect location. C-149 9-1267 Figure C-39 near here In 1960 the deposit was discovered by Leo Mark Anthony (a mining enginejer working for Moneta Porcupine Co.) through following up glacial float containing chalcopyrite (Anthony, 1977). Six claims were staked on the prospect in that year. Later/ brief investigations were made of the I | deposit by the USGS under MacKevett in 1966, George Moerlein in 1968, j and the Bureau of Mines in 1975 and 1976. The bulk of the work pre- ! i sented on this prospect was completed by a Master's thesis student i ii ID- employed by the Bureau of Mines. In 1977, she camped on the prospect j for four days while mapping and taking samples. j i I Geology j | 13 The Margerie Glacier deposit consists of a massive Tertiary porphy- 14 ritic quartz-monzodiorite stock intruded into the same sequence of marine i 15 i volcanic and sedimentary rocks that are found at Orange Point, seven ! i 16 miles to the south-southeast. This stock contains a porphyritic quartz 1 monzonite core. A prominent joint set trending N50°E and dipping , i 13 steeply northwest cuts across the stock and extends into the adjacent country rock. Porphyritic monzodiorite dikes ranging in width from one to 50 feet, and quartz sulfide veins up to 1.7 feet wide occupy the 21 joint set. The dikes extend into the country rock but the veins do not. The quartz-monzodiorite host rock, its core, and the dikes contain 23 disseminated sulfide mineralization. The joint system was probably the conduit for this sulfide mineralization that replaces mafics in the host 24 rocks. Limited investigation indicates that significant disseminated mineralization does not extend into the marine C-150 137° 05' I Jmi 1 I I 0 .5 II Contour interval 100 feet 59° 00' Base from U.S. Geol. Survey 1=63,360 Mt. Fairweather D-3,I96I and D-4,I96I Skagway A-6, 1961 Figure C-39 Index map for Margerle Glacier and Tarr Inlet knob area C-151 section and/ where the dikes extend into the marine section/ they contain much less sulfides. Figure c^0 is a geology and sample location map of the deposit. Figure 040 near here Alteration in the stock and dikes takes the form of plagioclase subjected to slight-to-moderate sericitization and K-spar alteration and biotite subjected to moderate chloritization. The disseminated sulfides are chalcopyrite^pyrite and pyrrhotite. Powellite-scheelite was also found associated with disseminated sulfides. Spaced-chip samples across the stock and dikes ranging in length from 3.1 to 100 feet contained up to 4/400 ppm copper/ 1.5 ppm gold/ 15 ppm silver/ and 634 ppm tungsten. Table C349ives the analytical results. The disseminated copper-bearing mineralization forms a large ftdrtheast^trending Table G34near here zone that ends near the northeast and southwest stock marine section contact and is open to the northwest under the Margerie Glacier. The region between the Margerie Glacier and this zone consists of steep cliffs and permanent snow fields, and was not examined. To the southwest very limited investigation indicates the disseminated mineralization grades out. The area of disseminated copper-bearing mineralization shown in figure£40 was defined by field observation and sample results. It C-152 Bos* from (J.S.G.S. I 63,360 Geology by MParke ond J. Still Skagwoy A-6 1961 Glacial ice and permanent EXPLANATION snowfields Porphyritic quartz monzcdiorite Porphyritic quartz monzcnite stock (Tertiary) core, less mafic than the remain der of the stock Contains northeast trending vertical porphyritic monzodiorite dikes up to 50 ft. thick and vertical quartz-su If ide veins up to 1.7 ft. thick. Metamorphosed layers of andesite, Area of known disseminated chal- shale, and limestone (Permian) copyrite mineralization Contact Gradational contact 57-5S '-ocat'on °f samples collected Location of sample of dissemi- ./ V 4-5 * from veins or narrow stringer noted mineralization, showing zones, length to scale direction of sample line Location of sample collected from Float sample location from just 8I a narrow vein, pod , or mineralized "20 outside map area zone Assay data given in tables C-34 and C-35 Figure C-40 Margerie Glacier porphyry copper deposit, sample locations C-153 TableC'31/ Assay WVp! Analysis Sample Length Sample' Type Feet (m) I fl Mo Oesription H5" 4 PEC. 53 L n.iO K) 5el«c4 ia IOO IQ. 32: Z3g 0.7 A CD 6 NJ iCO 4X IMS IOO 30,5 KJ L. u SPEC IOO 30.5" L I.S-Q 100 o ^ 53 lO. 0.70 7 10 zoo \}\-z .2J. Je. &i£ ±i. L 3,9 \ Pfte . r oixxp 30,0 q. ISO 7? N» Si M 200 M ipec zo ir .HO 1(0 /COO M 0.25" Ni ft, TO ". 2- CMQ 10 TO IOO ft' ^'riup 53 2-0 Cb ro o.zo 1 H 1,0 It- 52T 500 /O ftiz.. \\}-z... SUrk 0.10 30 M . Sfork Ju 'dxcp ZO o./o 3 CoO M /OO 11 O.G M Ifcfrff 1,2- 070 2 ;g)up 20 317 10 14 extends from an elevation of 1,100 feet to 2,100 feet, and over a horizontal distance of 2,000 feet. Less important than the disseminated mineralization are the fracture or joint filling quartz sulfide veins that are found throughout the stock area. These strike northeast and most have a vertical or steep northwest dip (two veins, 6S096 and 6S097-98 have a 45°southeast dip). They range in width from 0.3 foot to 1.7 feet and contain quartz, chalcopyrite, arsenopyrite, sphalerite pyrite, pyrrhotite, powellite-'scheelite, and molybdenite. Continuous chip or channel samples taken across these veins contain up to 11 percent copper, 20 ppm gold, 150 ppm silver, 1000 ppm zinc, 700 ppm molybdenum, G10,000 ppm arsenic/ 6J.06 ppm tungsten, Gl,000 ppm bismuth, and 500 ppm tin. TableO35 gives the analytical results. Limited investigation indicated that the type of quartz sulfide Tableo-35 near here vein described above does not extend into the marine section. Very limited investigation of the marine section to the northeast of the stock did not reveal any significant ore metal mineralization. However, brief investigation of the stratigraphic section to the south and west of the stock from an elevation of 1,100 feet to an elevation of 3,200 feet did reveal interesting mineralization. Figure e40 shows the sample locations and table e35 gives the analytical results. Two spaced- chip samples (6S079-080) of iron-stained zones in the marine section to the south of the stock at elevations from 2,825 to 3,200 feet contained C-155 $!? S^jp- Sx- V* rc fc'y O Cw ° -0 C- "8 s - Q s 8 Sb A A. u Xi 0 >» KJ \ a Krw C^ w °\ oOv O 8 = !7 "7 gfe 03 ^io 8 8 S';5! ^ t ; I i5 \ Oo Table £-3 Assay data4ft«*5<*'' « vet* Analysis PARTS PGR. MILLION Sample Length A. I Sample Type Feet (m) UU Zh 6; M Oesription 125" 0.7 :2.J 50 M 00 N K) 30 10 .30 1O coo M .27 .ZO 100 60 o. r 300)0 q.o 20 G,iax> 151 - 0 //a U 20 o " t ICO ZO I .35 /o 4te > + ^ iu A5- to. o.t, 10 /CO U 300 SPEt 2.V .7J -30 /30 20 10 O.I 20 .f 30 6ICCO 30 £ .3-; 15 75 |00 M l.o (600 zr 10 75 GitOOCO too o.s 5S6_ .50 SCO 0? 300 5^0 325"! .ZO 50 M ,3o /00 Iflw 660 0,7 11,000 //qo 5000 too M- /.o r/o 20O 65*B ifzoo 1500 M a is 30 130 20O IOOO N SfCC £>. ,20 ll000 I&O 30 61000 10 T.OO 30 too M 700 10 SPEC A3 £70 N JO 35 20 D/A srec 5- S < 200 M Iw /£"1 50 M Ob $6 too toooo 200 6.5* / v / 200 30O '' Table C-3S" Assay datafl- it (oic-Rl- Sample Length X-RKV SPfc I Sample Type Feet (m) tu Au As Desription 5SI5O o. / ,2-0 zo 360 /oo M 2-0.5" M fO .02- Mo 21O 500 M 5-0 5"0 ~>Z FSfSY JO N 7i < o .7 16 o 7JL 5SITC. "l c .76 ,5 H1 Ln ./O 40 M 20 >f 2. 00 .05^ o.i? 320 15 M M A2- 40 77 25" 10 N 18 20 .30 too C C /si ^ M J U.tt ISO rK.,11,-44. 1 ' £ k .' IMO hi lOGO srec 8; 5-0 N M (.od N M 10 Sk\4ii.c. t>c>di I'K up to 280 ppm copper, 50 ppm tungsten, 180 ppm zinc, 1£00 ppm arsenic and 30 ppm tin. Above 3,500 feet and to the south, a glacier covers the outcrops. Exposed at the stock marine section contact on a narrow 2,400- foot elevation ledge are quartz sulfide fracture fillings that strike N3C£-4d£ and dip from 42^-67° northwest. These fracture fillings cut across the contact, are 0.04 to 0.17 foot thick and are separated by 3-5 feet of wall rock containing disseminated sulfides. The fracture fillings (5S150-161) contain up to 1.8 percent copper, 0.15 percent tungsten, 0.25 ppm gold, and 20 ppm silver; and traces of bismuth, arsenic and tin. The wall rock contains up to 0.15 percent copper and 0.15 percent tungsten. Extent of this mineralization could not be determined because of steep overhanging cliffs above and below, and a snow field to the east. At an elevation of 1,950 feet and just to the southwest of the stock marine section contact, a one-foot thick sulfide-rich fault gouge striking N40°E and dipping 45° south extends for 400 feet or more. It contains up to IpOO ppm copper, 397 ppm tungsten, 2.5 ppm gold, ten ppm silver and greater than 10,000 ppm arsenic (6S102-103). Southwest of the stock marine section contact an irregular lens of massive pyrite, pyrrhotite and chalcopyrite containing 0.17 percent copper, 0.13 percent zinc, and 1.5 ppm silver about two feet across was found in greenstone (7S023). Further southwest at an elevation of 1,080 feet below extensive iron-stained cliffs of volcanic and sedimentary rocks float (6S108) was collected that contained 0.18 percent copper, one ppm silver, and 1.5 ppm gold. MacKevett and others (1971) reported massive sulfide float containing C-159 0.3 percent copper and 0.3 percent tungsten, probably from these same cliffs. Resources of the Margerie Glacier deposit Leo Mark Anthony (working for Moneta Porcupine Co.) estimated the dimensions of the mineralized zone as being 2,000-plus feet long and 400-plus feet wide. Through trenching and surface sampling, he estimated the average grade of the deposit to be 0.36 percent copper with traces of gold and silver (written communication, Leo Mark Anthony, 1977). Details or specific locations of the samples are not available, however. This may be the best grade estimate on the deposit to date. In 1968 George Moerlein briefly visited the prospect and estimated that the best mineralization was found in an area about 1,000 feet by 500 feet across, and his representative samples of the area showed a range of 0.327 and 0.403 percent copper and 0.01 ounces per ton gold. * This investigation estimates the zone of disseminated sulfides containing copper, tungsten, silver and gold mineralization is at least 900 horizontal feet wide, extends for 2,000 feet and is inferred to be 1,000 feet deep. FigureG40 shows the area of known mineralization. The depth estimate is based on the extent of known disseminated mineralization over a vertical distance of at least 1,000 feet. The volume formed by the above dimensions is in the shape of a prismatic parallelogram. If a tonnage factor of one ton per 11.5 cubic feet is assumed, there are 160 million tons within the volume described above. Grade was estimated from 19 spaced-chip samples ranging in length from 3.1 to 100 feet and ranging in value from 150 ppm copper to 4,400 ppm copper. The estimated C-160 average grade is 0.2 percent copper, 0.008 ounces gold per ton, 0.13 ounces silver per ton and 0.01 percent tungsten or $5 per ton. This is an approximate estimate based on sparse sample data but the copper values compare roughly with previous estimates. Detailed sampling could reveal smaller higher-grade areas. This study also estimated the -resources of the most continuous quartz sulfide veins. The economically most significant vein was traced through intermittent outcrops across scree slopes for about 700 feet (6S109-114). The highest value section of the vein contained 11 percent copper, 3.5 ppm gold, 100 ppm silver and 0.1 percent zinc, for a 0.65 foot width (table C-35, 6S109), or a value of $30 per ton at a four-foot mining width. The average value of the vein (21 - 27, figure C-40) over the 700 feet at a four-foot mining width was 0.50 percent copper, 0.05 ounces gold per ton, and 0.4 ounces silver per ton, or $15 per ton for an inferred tonnage of 75,000 tons. Other veins have somewhat higher values for lengths of about 70 feet but the veins do not persist. In summary, this deposit has an estimated inferred gross in place value of about $800 million in copper, tungsten, silver and gold. Potential of the Margerie Glacier deposit vicinity Considering the usual north-south elongation of intrusives in the area, the Margerie stock may extend for some distance to the northwest under the glacier along with associated mineralization. Diamond drilling through the glacier northwest of the outcropping deposit could reveal additional deposits or extensions of the known deposits. C-161 Significant showings of copper, silver, gold and tungsten near the southwest stock marine section contact indicates the potential for important massive replacement, vein or contact-type deposits. Tarr Inlet knob prospect and vicinity The Tarr Inlet knob prospect is located on the west side of Tarr Inlet about two miles south of the Margerie Glacier and two miles south east of the Margerie Glacier deposit. Figures C-2 and G39 show the prospect location. Wright (1937, p. 221) reported copper mineralization located just south of the Margerie Glacier. In 1944 two claims were located in the area (described as being two miles southeast of the Margerie Glacier and 1,500 feet from mean high tide). Geological Survey work in the area in 1966 (MacKevett and others, 1971) resulted in finding rock samples containing 200 ppm copper, 100 ppm molybdenum, 5000 ppm arsenic and a trace of gold, and a stream-sediment or panned concen trate sample containing 1£00 ppm copper, 50 ppm bismuth, 100 ppm tungsten and 15 ppm tin (Plate III, location 24 ). Bureau of Mines work in 1975, 1976 and 1977 consisted of geologically mapping the area, sampling important mineralized zones and taking stream-sediment samples. The Tarr Inlet knob is composed of Cretaceous quartz-monzodiorite containing large xenoliths of shale and volcanics. Porphyritic granite is found at two locations, probably in the form of small plugs. Cutting the Tarr Inlet knob are fault zones with associated shear zones that vary in width from a few feet to 200 feet and are often brightly iron-stained. Most of the ore metal mineralization occurs along altered fault zones with orientations of N20°-3dfa and NlcP-30%. The C-162 mineralization found along the fault and shear zones consists of pyrite, chalcopyrite, sphalerite, arsenopyrite, and quartz. Although anomalous metal values were found for an area extending for two miles and from elevations of 0-1,400 feet, most of the more significant mineralization was found to the east of the Tarr Inlet knob ridgeline at elevations from 0-500 feet. Figure C41shows the prospect geology and sample locations, and table gives the analytical results. FigureC-41and tableC-36near here Similarities in mineralogy, ore metals present, alteration and structure between this prospect and the Margerie Glacier deposit located 2h miles west suggest both may have been mineralized by the same process. Stream sediment samples taken along the west side of Tarr Inlet knob are highly anomalous in copper, zinc, silver, arsenic, gold, bismuth and tin, reflecting values in rock samples in the area, figure(341and table C-36, A stream sediment sample taken northwest of Tarr Inlet knob in a tiny stream draining a 1,000-foot high cliff contained 0.3 ppm gold, 50 ppm tungsten and 150 ppm chromium, figure^l and tableC-36. Samples of richer portions of the mineralized zones ranging in width from three to 16 feet contained up to 3^300 ppm copper, 5pOO ppm zinc, 3J.OO ppm lead,'50 ppm silver and 0.15 ppm gold. A ^-foot sample contained 0.48 percent copper, 4.3 percent zinc, 100 ppm silver, 1£00 ppm lead, and 0.15 ppm gold. As they are now known, these mineralized zones are too small and low-grade to approach being economic. C-163 TARR INLET N Contour interval 100 feet 0 1000 2000 [mil I I feet I r " meters 0 200 600 Base from U.S. Geol. Survey 1:63,360 Geology by M. Parke Mi Foirweather D'3 t and D - 4, 1961 and Skagway A-6, 1961 Explanation Alluvium Porphyritic granite Shale Quartz monzodiorite (cretaceous) Contact Probable fault X 6R02I Sample location Assay data given in table C~36 Figure C-41 Tarr Inlet knob prospect and vicinity,sample locations C-164 Table C- 36 Ass ay dataT«»>. 1/3 Analysis Sample Length Aft AA smc Sample Type Feet (m) ," flo W As Desription Oy.p 2- M \\\ M Oi5A-5h3ji/^e/i L ror/? o mb MO lO KJ M 2-Chip MS 10 ^4 M 5.D fT 70 i M H N) M M.fc Mo 50 in M M M c o IO M 10 S' Mt.QS) M M N zo qo M IO I' chiP- 10 3.0 qo M Ni 6SC62- ''cKtp 30 q. s\ M L 10 |0 5 M iKxi\ O.^CCJ'k Cl JXl.Ct>p cr 00 CD < 8? I/O" to (V M O3 w en J\ t o rr - MS b I 5 5 b 3 C 3 I S Q. Q ; a 01 B P y> CM UJ O (A Ic J\ I 1 T- \ O 00 o O \J 8 O (J\ D S P O Q o O 0 O o O 7 CA 0 i 0 ' 7- 7 Oo *? CA OM J MO 0 D °\ 7 r 7 7 7 7" r z w> r Jo O 8? D O "7 7 A m 6 B Table Assay Tv\\«4- kv\o(o <*/J,TK Analysis Sample Length AA spec. S.KC Sample Type Feet (m) w M Desription 7M tttt -3,0 /8&C IO K) 6D 'Chip 10 lOQ MOO I 'C w 181 fi 3.0 50 L ,05" I10A xchXp ID 3.0 ZO 0 L N) 10 ID ,2. 3000 50 Stir fl VV/v. e& l o ' 15* I 55 Ki .?£> 5D 12CO ?£> 95' 'M lO.iOO -10 O oo 2-0 .10 1COO too 5"CO 3.51) 1- ao M 10 M JA l N M PS Ml 16) 10 L_ M \\ HO L. M SO M Ki Ni Mineralization is widespread d,n the Tarr Inlet knob area and the area presents an excellent exploration target. North side Johns Hopkins Inlet gold anomaly A stream sediment sample collected at an elevation of 1,200 feet on the north side of Johns Hopkins Inlet contained 24 ppm gold and seven ppm silver. Figure G38 shows the sample location. This stream drains the south side of a 4,300-foot high mountain consisting of mainly green- schist. Iron-stained zones located on the south side of the mountain may be the source of this gold anomaly. Johns Hopkins Inlet molybdenum anomalous area Numerous molybdenum anomalies are found in the marine volcanic and sedimentary section found on the north and south sides at Johns Hopkins Inlet. Most are in shale or its metamorphic equivalent and some are in the volcanic rocks of the Orange Point deposit. Values range up to 300 ppm molybdenum for in place samples. Anomalous copper is also occasionally found in these samples. Figure G38 is a map of the area showing the sample locations. The molybdenum in this section is an excellent source of mineraliza tion for contact-type or more important porphyry-type deposits. Porphyry- type mineralization occurs at the Margerie Glacier copper deposit seven miles north, at the Threesome Mountain molybdenum deposit 30 miles south, and at the Nunatak Molybdenum deposit 35 miles east. A sample of rock float collected on the south side of Johns Hopkins Inlet contained a %-inch thick quartz molybdenite-chalcopyrite vein cutting a hornfels host rock. (This sample, 7S097, contained G2,000 ppm molybdenum, 610 ppm copper, C-168 0.20 ppm gold, two ppm silver and 50 ppm tin.) This may be an indication of a porphyry-type deposit in this area. Thorough examination should be made of the granitic intrusives and their associated fracture zones found in the area for this type of mineralization. Other anomalous areas in the Margerie Glacier favorable area In addition to those areas previously described, there are numerous other prospects and anomalous areas located in the Margerie Glacier favorable area that may prove important leads in finding more significant mineralization in the area. Table G37 gives information on Table C-37 near here these anomalies and plate III shows their location. Of note are the numerous float samples found on the south side of Johns Hopkins Inlet ( 29-31) that contain up to 4600 ppm copper, seven ppm silver, 700 ppm tin, 0.15 ppm gold and 793 ppm tungsten. This area with its extensive intrusive marine section contact zones and numerous large, iron-stained areas presents excellent exploration targets for contact or replacement- type deposits. Rendu Glacier favorable area The Rendu Glacier favorable area has a maximum width of three miles and a length of five miles consists of a rugged north by northwest-trending mountain ridge (maximum elevation, 5,650 feet) located between the Rendu Glacier to the northeast and an unnamed glacier to the west. FigureC-l and plate III show the general area location. C-169 Table C-37 Korth Geikie subprovinca, Mar-: trie Glacier favorable area, occurrences not discussed in text No. on Name on nain Source of ol a t.c T 1 1 prospect Commodity Location Description of deposit Mining claims Samples I/ information Remarks 23 West shore Cu West shore of Chalcopyrite and pyrite Claims re- MacKevett (1971) reports MacKevett, "Location of Tarr In Tarr Inlet, occur as disseminations portedly staked that a composite grab 1971, p. 40, unknown. let 1 1/2 miles in altered zones frcn 1 to in the vicinity sample representing one 43, 54; D.A. Brew, south of the 8 feet wide in horn(els. before 1906, of the best mineralized location written Margerie but not'con outcrops containedi1,500 no. 18 f communication Glacier. firmed by claim ppm Cu, 100 ppm W, 50 Wright and 1977. O records investi- ppm Bi and IS ppm Sn. In*- Wright, 1937, I gation. Two vestigation of the area p. 221, claims were in 1975 failed to reveal George A. staked in the any significant ore metal Moerlein, area in 1944, mineralization. Brew 1968a. (written communication, 1977) indicates that this was a stream sediment or panned concentrate sample of unknown location. 24 West shore Cu, Mo West shore of Altered and brecciited None recorded Three samples of altered MacKevett, of Tarr Tarr Inlet, zones in granodiorite zones from 2 to 12 feet 1971, p. 32, Inlet 2 miles generally between 2 and thick contain up to 200 35 and 74, southeast of 12 feet thick. ppm copper, 100 ppm location no. the Margerie molybdenum, 5/000 17. Glacier. ' arsenic and a trace of gold (AAS analysis) . 25 Stained Three and 1/2 North zonei pyriui com- None recorded George A. zones miles (north prised 1 to 3% of i shear Moerlein, bOUth Of zone) arid 4 zone in argillite. South 1968a. the miles (uouth zone: massive pyrite occurs Margerie zone) south or along an assembla>j i of Glacier the liargerie leucogranite, diorito, Glacier at an limestone and slat::. No sul- elevation of fides other than ,;,rito occur app. 2,500 ft. in either zona. -North Geikie subprovince, Margerie Glacier favorable area, occurrences not discussed in text, con't. Table C-37 No. on Name ofi Main Source of plate in prospect Commodity Location Description of dei osits Mining claims Samples I/ information Remarks 26 West of Cu West of Tarr Pyrite and chalcoj yrite None recorded MacKevett (1971) reports MacKevett, "Location Tarr Inlet Inlet at an occur as massive veins and that a grab sample from 1971, p. 40, unknown . " elevation of as disseminations in al one of the lenses con 41, 51, 55,- D.A. Brew, app, 1,700 tered lenses in 1> acocratic tained 1,000 ppm Cu, 300 location no. oral feet. granite. ppm Zn and 1 ppm Ag. 63. communi cation. 1977. , 1 27 3,850 Cu Worth side of Pods of massive si. If ides None recorded Chip samples of the sul- This in J~J nunatak Johns Hop- up to 1/2 feet across near fide pods contain up to vestigation. H-> kins Inlet 2 a granitic, volcanic, lime 770 ppm copper, 190 ppm miles north stone contact. Tiie sul- zinc (all AAS analysis) of the Orange fidus are pyrite, pyrrhotif.a^ and i.'j ppm silver. Point deposit and som& cha loopy rite while at a 3,850 the gangue mineral sr are -.diopside ft. nunatak side>garnet, acti.iolite, chlorite, quartz, and epidote. 2b North of Cu North shore Altered zones bet/een 3 None recorded Grab and spaced -chip MacKevett, "Although Johns of Johns and 100 feet wide in meta/- samples of the altered 1971, p. 34, some of Hopkins Hopkins In- morhpic, intrusiv >, and zones contain up to 38, 51, 52, the al Inlet let from the volcanic rocks. 1,000 ppm copper, 15 ppm location no. tered point opoo- * molybdenum, 1 ppm silver 64; zones are , site Laroplugh and 0.1 ppm gold (AAS Reed, 1938, large, all Glacier to 4 * analysis) . p. 58, 59. of them miles west of. * appear to the point. * be too low grade to encourage explora tion." (MacKevett 1971, p. 52.) Table C-37 North Geikie subprovince, Marge::ie Glacier favorable area, occurrences not discussed in text'/ con't. No. on Name of Main "Source of plate HI prospect Conunod i ty Location Description of deposit Mining claims Samples I/ information Remarks 29 South Cu.Ag South side of Hornfels float containing None recorded A sample of float con This in- Approx. side of Johns Hopkins sulfides was fount! at this tained 4,600 ppm Cu (AAS vestigation. same Johns Inlet, 2 locality. analysis) , 7 ppm Ag, location Hopkins miles north and 300 ppm Co. as 632, Inlet west of the plate l f Lamp 1 ugh location Glacier at no. 65. an elevation O of approx. 1 150 feet. * -Jto ______30 South side Cu, South side of Float containing None recorded A sample of float con This in of Johns Sn, Johns Hopkins pyrrhotite and cl al-; tained 4,100 ppm Cu, 250 vestigation. Hopkins In- W, Inlet, 2 copyrite was found at ppm Zn and 0.15 ppm Au let. A. miles north this locality. (all AAS analysis) ; 7 east of the ppm Ag, 700 ppm Sn, and Kashoto 793 ppm tungsten (x-ray) . Glacier at an elevation of approx. 900 feet. 31 South side Cu South side of Hornfels float con- None recorded A sample of float con This in of Johns Johns Hopkins taining quartz w. th tained 410 ppm Cu (AAS vestigation. Hopkins Inlet, 1 mile chalcopyrite was found analysis) , 20 ppm Sn Inlet. northeast of at this locality. « and a trace of Ag. the K-ashoto f Glacier at an* elevation of approx. 400 ft. Table C-37 North Geikie subprovince. Marc, srie Glacier favorable area, occurrences not discussed in text, con't. Ho. on Name of Main Source of frlate III prospect Commodi ty Location Description of dooosit Mining claims Samples I/ information Remarks 32 East of Cu About 3/4 Pyrite, pyrrhoti':e and oc- None recorded Two spaced chip samples MacKevett, Kashoto mile east casionally borni-.e occur taken for IS.7 and 6 ft. 1971, p. 41, Glacier of the as dissemination.; in across the width of the 52; location Kashoto greenstone near u con stained zone each con no. 75. Glacier. tact with granod'.orite. tained 0.10 ppm Au, 190 This investi The sulfide-bear ,.ng and 140 ppm Cu (all AAS gation. zone is moderately analysis) , and a trace O stained. and 1 ppm Ag, respectively. J- 34 Mt. Copper Zn Southwest Weakly-mineraliajd al None recorded A random grab sample of MacKevett, flank of tered zones occn: in iron-stained hornfels 1971, p. 55; Mt. Copper iron-stained pyretic contained 0.10 ppm Au (AAS location no. at an hornfels. , The altered analysis). MacKevett 66, elevation zones are best (1971) reports that a this investi of 4,900 ft. developed near r' tnu- composite grab sample of gation. grainod porphyri:ic iron-stained hornfels dikes that cut t.ia contained 15,000 ppm Da, hornfels. 300 ppm Cu, 15 ppm Mo and 300 ppm Zn. Table C-37 North Geikie subprovince, Margerie Gli.cier favorable area, occurrences not discussed in text, cori't. No. on Name of Main Source of olate in. prospect Comroodity Location Description of'deposit Mining claims Samples l/~ information Remarks* 35 Southwest Cu Southwest of An intensely iron-stained None recorded A 2.3 ft. chip sample MacKevett, The of Lomplugh Lamplugh zone more than one-half taken across a heavily 1971, p. 52, proximity Glacier Glacier a- mile .long and one-quarter - iron-stained section of 79; location of this bout 5 miles mile wide occurs in horn- the zone contained 67. mineral frorn the fels and metadior:te. 230 ppm Cu (AAS analysis) This investi occurrence terminus, Abundant pyrite is present and 0.5 ppm Ag. Two com gation. to meta- between throughout the zci>u, oc- posite chip samples taken volcanic O elevation of curring as dissem:nations across a large section of units and I 3000 and and in massive stiingers the zone contained 0.20 the pre 3400 feet. and lenses up to ( .5 ft. ppm and 0.25 ppm Au (both sence of wide. A few. pyrilu-rich AAS analysis) and N to abundant quartz veins up t<. 0.8 ft. 10 ppm Mo, respectively pyrite wide occur in the hornfels. A 28 ft. chip sample taken suggest a across a section of the similarity zone containing abundant to the pyrite contained, 0.05 ppm Orange Pt. Au (AAS analysis). Mac- volcano- Kevett (1971) reports that genie de a select grab sample of a posit. pyrite-rich quartz vein con Further tained a trace of gold (AAS investi analysis), 300 ppm Cu and gation of L Mo. A select grab sample the area of copper-stained hornfels is war contained 50 ppm Cu and 50 ranted, ppm Mo. but the snow cover & very rugged terrain will be limiting factors. Table C-37 North Geikie subprovince, Margerie Glacier favorable area/ occurrences not discussed in text, coh't. No. on Mama of Main Source of plate III prospect Commodity Location Description of dep isit Mining claims Samples I/ information Remarks 36 Southwest Ni Southwest of An intensely iron-stained None recorded Two spaced chip samples MacKevett, See note of the Jiead the head of altered zone occur in taken for a combined 1971, p. 79, on 35. of Lamp1ugh Lamp1ugh hornfels near a co.itact length of 38.5 feet a- location no. Glacier. Glacier at with sheared leuco cross the width of the 68; an elevation adamellite (quart:; diorite) stained zone. One this investi of 2,900 ft. and hornblende andisite. sample contained 0.10 gation. Abundant disseminated py- ppm Au, the other a trace rite is present through of Au (both AAS analysis). out the atained zo :e which Both contained 5 ppm Mo en is at least 40 feu: wide and 5% Fe. MacKevett and about 7 150 feet long. (1971) reports that a select grab sample of the best appearing material in the stained zone con tained a trace of Au (AAS analysis), 150 ppm Cu, 150 ppm Co, 200 ppm Cr, 20 ppm Mo and 300 ppm Ni. I/ All sample values cited were obtained from semiquantitative spectrogrsphic analysis, unless noted otherwise. The first recorded activity in the area was the staking of the Ship claim, located two miles northwest of the head of Rendu Inlet by J.P. Ibach in 1937. In 1960 Leo Mark Anthony reported finding rock float containing chalcopyrite below the mountain ridge discussed above (Anthony 1977 f written communication). In 1966 the U.S. Geological Survey reported finding similar float and reported an iron-stained zone at an elevation of 4,000 feet in the area (MacKevett and -others, 1971). For the most part, the area:is composed of jagged mountain ridges and steep glaciers, and requires the use of helicopter and mountaineering equipment for exploration. It is little explored. The mountain ridge consists of a mixed contact zone, a Devonian sedimentary section and Cretaceous intrusive diorite. Figure (342 is a Figuree42 near here geology sample location map of the area. The sedimentary section is composed of argillite, limestone and some volcanics. At places, this section is metamorphosed to hornfels, marble or calcsilicate hornfels. The mixed contact zone consists of diorite mixed with partly assimilated sedimentary rock including large blocks of limestone. The eastern side of this mountain ridge is mostly covered with glaciers and snow fields while the western side of the ridge consists of a steep, broken mountain face up to 3,000 feet high, occasionally laced with ice and snow-filled gullies. Exposed in the mixed contact zone on this mountain face for two miles and at elevations from 4,000 to 5,000 feet are iron-stained layers and masses. C-176 136° 50' !36°45' 6R020 iifr-T:\r. % 66B no' Base from U.S. Geological Survey 1:63,360 Skogway A-5, 1961 EXPLANATION Glacial ice and permanent sno*f;elds Marine stratigraphic section comprising argillite and limestone with some vol- Mixed conloct zone- canics, upturned and folded, containing Oiorite containing partially assimilated some layers that are highly iror- blocks of marble and afiicr metasedi- stained (Permian and Devonian) menfary rocks. Layers and masses of iron-stained rock occur between elev. af Contact, dashed where indefinite 4000 to 5000 ft. Those examined were tactite zones 75075 Sample of outcrop X Tactite float containing chalcopyrite (no anal White diorite, highly fractured (Cretaceous) ysis} 6S053 Rock float or stream sediment sample A Assay data given in table C-38 Figure C-42 Rendu Glacier favorable area, sample locations 0177 Similar layers but more difficult to" access are found on the east side of the mountain. Helicopter observation indicates these layers are up to 50 feet thick, strike with the mountain face, dip gently into it and are up to 1,000 feet long while the masses are up to 100 feet in maximum dimension. In the southern portion of this western mountain face, highly fractured white diorite forms a sharp contact with the mixed contact zone. Figure G43 is a photograph showing this contact and the deposit associated with it. Figure G43 near here Bureau of Mines work in 1976 and 1977 consisted of investigating rock float at the bottom of the mountain face and, through use of technical ,'nos rock- and ice-climbing gear, investigate the more accessible iron- A stained zones. This resulted in the discovery of a high-grade chalcopy- » rite contact-type deposit containing copper, tungsten, silver and gold. The main occurrence (named the Massive Chalcopyrite deposit) is located at the above mentioned contact of the diorite and the mixed contact zone, but numerous showings of similar mineralization extend for at least 2h miles. The -prospects for additional contact-type tungsten, copper, silver, and gold deposits are excellent. Exploration will require detailed examination of the mixed contact zone and its contacts with intrusive white diorite, and the diorite's contact with an extensive stratigraphic section of limestone and argillite to the south. This 0-178 Goat spotted In 1976 rassive__ ChalcopyrFte ixed rope, ice gully epos it skam showing C7S061) (6S048-050) opper-stained zones Mixed contact zone: diorite with inclusions of marble and other metasedimentary rocks Indefinite contact White diorite Figure C-43 Oblique aerial photograph of the west side of the Rendu Glacier favorable area, showinq_copper-stained zones and sample locations ~C-179 r 9-1267 type of deposit is the only* important source of tungsten and, in terms 'of extent and type of mineralization, this area bears some similarities to) i Bishop California which, to date, has produced h billion dollars (1978 ; j prices) in tungsten, copper and molybdenum. Also, it is important to I i note that porphyry-type copper deposits can also be associated with high i temperature contact deposits. The area is too little explored to rule i out this possibility. ; Massive Chalcopyrite deposit i MacKevett and others (1971, location 15) reported float containing i 10 copper below a steep mountain face located west of the Rendu Glacier. Investigation of this area by the Bureau of Mines in 1976 revealed tactite i float containing anomalous copper or tungsten extending for 2^ miles. ! 12 i Figure C-42 shows the sample location and table C-38 gives the analytical results. i 15 Table C-38 near here i i 16 Helicopter reconnaissance along the mountain face above these mineral- i i ized float samples revealed a series of stained layers and masses extend ing for about 23s miles (see fig. C-42). Investigation by helicopter along these zones revealed several that were copper-stained and that appeared to contain massive sulfides. A massive appearing iron and copper-stained zone adjacent to a contact between the mixed contact zone and white diorite was observed at an elevation of 5,000 feet, 200 feet 23 below the ridge crest on a vertical to overhanging cliff 3,000 feet high. Figure C-43 is a photograph of the mountain face, showing the copper-stained zone (named the Massive Chalcopyrite deposit) and the mixed contact zone intrusive white diorite contact. T'ho 200-foot drop to this zone was C-180 . Table C-3&' Assay Analysis Somple Length A.A. 5 pee. IVA ft* Sample Type Feet (m) W W Description < / 100 12 3.7 50) .22.O 3-5" too 12 .7 500 210 22.6? 100 t C. VV ^ O.6, ,05 65 150 /f e. at ,50 3CT /CO -& o 75073 AZ- 7? N 00 /5T2- 7? /o iv) (.,05) Fixv! front > \ * «A « Sftt H /TO 3 JO 6)0 30 \4 L 20 Tlr*- L 5]QL .^^ Nl 10 i^ 12 10 5" ^ .7*? vi ,30 70 30 VI ^ Jl no 2.0 LlyJ^, spec H M Id IU tree 0 O O 0 M 30 N negotiated by securely anchoring a 150-foot rope to the ridge crest and repelling down the rope 150 feet and climbing down the remaining 50 feet using slings for protection. Limited footing on a narrow ledge limited the investigation. A massive sulfide zone is located between a 5-foot wide zone of epidote-bearing diorite that grade s into white diorite to the south and a 10-foot wide section of calcsilicate rock that graded into marble to the north. The calcsilicate rock was predominately garnet, epidote, and diopside with small sulfide and scheelite veins. The massive sulfide zone consisted of chalcopyrite, augite, geothite, pyrrhotite, scheelite and sphalerite. Petrographic examination indicated augite and scheelite had been replaced by chalcopyrite and pyrrhotite. The mineralization appears to be the result of metasamatic replacement of marble in a high temperature contact zone. About a 12-foot by 12-foot section of the sulfide zone was accessible for sampling and examination. The downward extent of the zone could not be determined accurately because the lower portion of it overhangs and there was insufficient rope to negotiate the overhang. By limited observation from the ledge and from the helicopter, the massive sulfide zone was estimated to continue down at least h rope length, or 80 feet. Additional iron and copper-stained zones were at lower elevations near the mixed contact zone white diorite contact, figure C-43. This 12 foot wide by 80 foot long sulfide zone here was named the Massive Chalcopyrite deposit because of the predominance of chalcopyrite. :. . C-182 9-1267 I ! i i i i "It is inferred to extend 40 feet into the rock face based on the custom often employed of inferring depth equal to one-half the length. Using an estimated ton per nine cubic feet density factor, this 12 foot by i 80 foot by 40 foot zone contains 4,300 tons. Two samples were taken "iI across this zone: one, 6S048, was taken across only two-thirds of the i, i zone; and one was taken along the middle of the zone (table C-38). The; 6 , i I ! :i average grade of the two samples taken across the zone is 0.52 percent i; I , I ; tungsten, five percent copper,'seven ounces per ton silver and 0.15 ; 8 i ! | j ounces per ton gold for a combined metal value of $215 per ton at i i February 1978 EMJ prices. The inferred gross in place value of this 'i 10 , I i i 1 1 ji deposit is $900 thousand. Four of seven grab samples (not shown in !j i table C-38-or figure C-44) from the 10-foot wide zone of calsilicate 12 j | I mineralization adjacent to the above zone contained from 159 ppm to : 13 i i | 11,000 ppm tungsten indicating the tungsten mineralization extends ', U i ; ; into the calsilicate zone. \ )5- j I } Mineralization in the vicinity of the j 16 i Massive Chalcopyrite deposit I j ; 17 ! Another accessible area of intensely iron-stained calsilicate ' 3 rock surrounded by the mixed contact zone was spotted on the cliff face ' 9 below a broken cornice about 400 feet north of the Massive Chalcopyrite :a~ deposit. Figure C-44 is a geology sample location map of the area. ! Figure C-44 near here i ______I Only the top of the calsilicate rock was examined about 30 feet above I its intensely iron-stained portion because loose rock prevented roped C-183 EXPLANATION Glacial ice and permanent snowfields Mixed contact zone- Diorite containing partially assimilated blocks of marble and other metasedimentary rocks (Cretaceous) White diorite, highly fractured (Cretaceous) Marine stratigraphic section comprising argil- lite and limestone with some volcanics , upturned and folded, containing some layers that are highly iron-stained (Permian and Devonian) Iron-stained skarn with massive sulfides. Only those zones that were sampled are shown Indefinite contact CD Lines of equal magnetic intensity, contour interval 400 gammas. Instrument used; Geo- Metrics UniMag model G-836 proton total field magnetometer Channel or chip sample location and analysis, 6S05I reporting tungsten, copper, and silver respec- ',1900,15) tively, in ppm. For sample sites with multiple X samples, the highest values obtained are reported Base from US. Geological Survey 1: 63,360 Geology by J. Slill Skagway A-5, 1961 0 500 1000 i i i. I I feet ' ' i meters N 0 100 200 300 Contour interval 100 ft. Assay data given in table C-38 Figure C-44 Massive chalcopyrite deposit and vicinity, sample locations and magnetometer survey results access to lower portions. It consisted of marble cut by a 0.6-foot thick iron-stained vein containing actinolite, chlorite, diopside, pyrrhotite, talc, chalcopyrite, and magnetite that assayed (6S051, table C-38) 0.19 percent copper/ 79 ppm tungsten, 15 ppm silver, 0.05 ppm gold, and 150 ppm cobalt. A 0.6-foot long sample of a larger tactite zone taken 1,000 feet northeast of the Massive Chalcopyrite deposit within the mixed contact zone (7S072', figure G-44 contained 1,500 ppm copper, 1.5 ppm silver and 0.5 ppm gold; while another located 2,000 feet southeast in the stratigra- phic section taken of iron-stained, interbedded marble and argillite (7S073, figure G4^ assayed 950 ppm copper and one ppm silver. A total field magnetometer survey was taken on the glacier in the snow-covered area between the above mentioned samples. Figure(M4shows the results of the survey. A sharp anomaly with a magnitude of at least 1,000 gammas is centered between the Massive Chalcopyrite deposit and sample 6S051, possibly indicating extensive mineralization under the glacier. Very limited investigation in the vicinity of the Massive Chalcopy rite deposit has revealed somewhat similar mineralization at several locations spanning thousands of feet with the intervening area covered with snow. The known mineralization in the area and the white diorite contacts with the mixed contact zone and the stratigraphic section form important exploration targets. C-185 Other._mineralization in the_.Rendu__Glacier favorable area Fixed-rope ice gully skarn showing About 3,000 feet northwest of the massive chalcopyrite zone is a prominent tabular-appearing iron-stained zone exposed below a large outcropping of marble at the bottom of a steep ice and snow gully about 700 feet below the top of a 3,000-foot high cliff. FigureG42shows its location. An attempt was made to reach the iron-stained zone in 1976 but it failed about 200 feet short of its goal because of lack of rope and ice pickets. In 1977, through use of ice pickets and by stringing 700 feet of fixed-rope, the iron-stained zone was reached but overhanging cliffs allowed access to only a small part of the zone. The iron-stained zone is about 20 feet thick, dips about 30° into the mountain and had a strike of about N20°W, and an exposure length of about 500 feet. Below it was diorite containing assimilated rock from the stratigraphic section and above was calcsilicate rock grading into marble. The iron-stained zone itself consisted mostly of pyrrhotite with minor chalcopyrite. A 10-foot long spaced-chip sample (7S061) across the top portion of the zone contained ],900 ppm copper, 0.10 ppm gold and three ppm silver. Crampon ice gully mineralized area An iron-stained layer located about one mile northwest of the Massive Chalcopyrite deposit was reached by ascending a 45° snow and ice gully on crampons for 1,500 feet to an elevation of 3,900 feet. The iron- stained zone reached was immediately below a ^-mile long stained layer 0186 (apparently hornfels) that could not be reached because of steep, wet rock. The iron-stained area consists of hornblende diorite with epidote and about two percent magnetite surrounded by the mixed contact zone. This tabular area is about 200 feet long and up to 20 feet thick, and strikes N20°E and dips 45°SE. A seven-foot long spaced-chip sample (6S054) taken of this layer contained 250 ppm copper, 159 ppm tungsten, 0.30 ppm gold and one ppm silver. FigureC42shows the sample locations. During poor weather, several iron-stained layers in the vicinity were observed from the helicopter to be copper-stained. Remainder of North Geikie sub-province Geologically, the remainder of North Geikie sub-province is somewhat similar to the areas already discussed in detail. However, no similarly large mineralized areas have been noted in this remaining portion of the area. Portions of the area are virtually unexplored, and the numerous small mineralized areas found where access was possible may indicate potential for larger areas of ore metal mineralization, some of which may be similar to those previously described. Little Jennie and the Silver Dick patented claims Little Jennie and Silver Dick claims were located in 1893, apparently along the west shore of Rendu Inlet, and patented in 1894. Development on the claims in 1894 consisted of a 65-foot long adit on the Silver Dick claim and trenching on both claims. Investigations in 1966 by the u.S.Geolo- gical^Survey (MacKevett and others, 1971) indicate the claims are located on an ankeritic carbonate quartz vein about six inches thick located along a dioritic dike marble contact on the west shore of Rendu Inlet. C-187 Earlier investigators, Buddington (in MacKevett and others/ 1971). and Rossman (1965b) also reported the claims' location on the west side of Rendu Inlet and indicate that the adit was covered by a landslide. They reported finding wire silver and tetrahedrite in the area. A copy of the mineral survey plot for the claims gives a latitude and longitude that plots on the west shore of Tarr Inlet and indicates a shoreline boundary for the east end of the claims. Plate III shows this location. National Geographic records indicate that in 1894 all of Tarr Inlet was under hundreds of feet of glacial ice. Investigation by skiff along the west shore of Tarr Inlet in 1976 and 1977 failed to reveal any indication of the claims, workings or silver mineralization. In 1976 during poor weather, a brief and unsuccessful attempt was made to find the prospect along the west shore of Rendu Inlet. Other mineralized zones and prospects in the remainder of North Geikie sub-province The location and information on the less significant mineralized zones in the remainder of North Geikie sub-province are shown on plate III and table C-39. Of note are a number of mineralized showings, some of them skarn-type mineralization on the ridge between Glacier Bay and Rendu Inlet. This ridge contains extensive Devonian limestone-Cretaceous Table 0-3 9 near here granitic contact zones in a setting similar to that of the Rendu Glacier area of high mineral potential. 0188 Table C-39 Remainder of the Worth-Gejkie subprovince, occurrences not discussed in text,con 1 t. No. o.n Name of Main Source of filate f II prospect Commodity Location Description of deposit Mininq 'Claims Samples I/ information Remarks 37 Upper 6+ miles east Banded gneiss slightly None recorded Three spaced-chip samples This in- Carroll of Mt. Barnard iron-stained on surface. 20-45 feet long across iron- vestigation. Glacier summit and 5 More intense iron- stained gneiss contained no miles north of staining to the north significant ore metal values. Massive Chal- but access more diffi copyrite oc cult. 'o currence at 1 4,300 feet M 00 elevation. VO 38 Mt. Cu 2 -1/2 miles Small pods up to 0.5 None recorded Grab sample of pod con This in Probably, Barnard east -southeast foot thick of pyrrhotite tained 1,000 ppm copperf vestigation. more of nunatak of summit of and pyrite with a trace 0.1 ppm gold (all AAS same in Mt. Barnard, of chalcopyrite asso analysis), 0.5 ppm silver vicinity elevation ciated with andesite, and 100 ppm cobalt. but in 500 feet. greenstone, epidote and vesti thin bands of limestone gation in or marble. Contact rugged metamorphic-abundant terrain chlorite alternation, may be some sericite alternation. difficult. 39 Stained North of Iron-stained zones occur None recorded George A. zones north Margerie discontinuously over a Moerlein, of Margerie Glacier a- broad area in fine-grained written com Glacier bout 2 miles clastic rocks. Pyrrhotite, munication, west of the the only sulfide noted, ^963b. terminus. comprises about 1% of the rock in the stainad zones. 40 Mt. Ni Approx. 2-3/4 Lens of copper- and iron- None recorded MacKevett (1971) reports MacKevett, «* Abdallah miles north- stained hornfels about 10 that a grab sample from a 1971, p. 79, Table C-39-Remainder of the North Geikie subprovince, occurrences not discussed in text. .No. on Name of Main Source of plate III prospect Commodity location Description of deposit Mining claims Samples I/ information Remarks 40, CQnfc, West of Mt. feet long and 6 feet lens contained 100 ppm Cu, location no. Abdallah at. wide occur at this and 70 ppm Ni. 16. an elevation locality. of 4,200 ft. .- 41 West side Cu Pyrite and chalcopyrite Hone recorded MacKevett (1971) reports MacKevett, . of Tarr occur in quartz-calcite that a grab sample from 1971, p. 40, Inlet veins up to 0.5 ft. wide. one of the veins con 51; location O The veins are located in tained 2,000 ppm copper. no. 62. 1 a 6 f t . wide pegmatic zone in granitic rocks. oE 42 Ridge west Mo Molybdenum, chalcopyrite, None recorded MacKevett, Location of Rendu pyrite and pyrrhotite 1971, p, 79 { uncertain Inlet occur in thin quartz veins location no. and quartz-rich pegmatic 60. dikes in a 25 ft. wide zone in granitic rocks. 43 West of the Cu West of the Sulfides, mainly pyrite, None recorded MacKevett (1971) reports MacKevett, _ mouth of mouth of occur as disseminations that a select grab sample 1971, p. 50, Rendu In- Rendu In and lenses in altered from one of the altered 73, 79, let let at an zones in bleached marble. zon&i contained 15 ppm Cu, location no. elevation The altered zones are up 30 ppm Ni, and 10 ppro Co; . 38. of 100 ft. to 200 ft. long and up to a select grab sample from 1 ft. wide. a pyrite-rich lens contained 1,500 ppro Cu, 1,000 ppm Ni and 700 ppm Co. Table C-39 Remainder of the North Geikie subprovince, occurrences not discussed in text, con't. No. on Name of Main Source of plate in prospect Commodity Location Description of deposit Mining claims Samples I/ information Remarks 44 West of Fe West of Rendu Magnetite-rich skarn de- None recorded MacKevett (1971) reports MacKevett, "Deposits Rendu Inlet at an posits occur near the con- that three select grab 1971, p. 53, exposed Inlet elevation of tact between marble and samples contained from 5% 70; location are small, 1/900 feet. diorite. A few mafic to greater than 10% Fe. no. 39. but much dikes cut the rocks ; some of the contain small pyrite-rich bedrock . ' pods near their contacts. is cov ered by surf ical deposits and the size and distribu tion of the de posits cannot be estimated accur ately ." MacKevett 1971, p. 70. 45 North Zn, Ag - Massive sulfides occur in None recorded A 3.5 ft. chip sample This shore of a carbonate-quartz vein taken across the widest investi- Johns ' in gneiss. The vein section of the vein con- gation. Hopkins pinches and swells, with tained 770 ppm Cu, 250 Inlet at a maximum width of 3.5 ft. ppm Pb, 4,300 ppm Zn, 0.03 entrance and extends approx. 100 ppm Au (all AAS analysis) ft. where it is covered and 15 ppm Ag. by overburden. Table C-39 Remainder of the North Geikie subprovince, occurrences not discussed in text, con't. Name of Main Source of prospect Commodity Location Description of deposit Mining claims Samples I/ information Remarks 46 Northwest Zn Northwest Iron-stained hornfels None recorded A chip sample of the shear MacKevett, shore of shore of contain finely dissemi zone contained 110 ppm Cu, 1971, p. 41, Johns Johns nated pyrite and a 0.3 130 ppm Zn, a trace of gold 55, location Hopkins Hopkins ft. wide shear zone. The (all AAS analysis), and 0.7 no. 76; Inlet. Inlet be stained zone appears to ppm Ag. A sediment sample this investi low the be fairly extensive. from the mouth of stream gation. O Kadachon transsecting the stained I Glacier. zone contained 0.10 ppm Au (AAS analysis). MacKevett (1971) reports that a select grab sample from the stained zone contained 300 ppm Zn. I/ Ail sample values cited were obtained from semiquantitative spectrographic analysis, unless noted otherwise. 9-1267 'Middle Geikie sub-province Introduction The middle Geikie province between Geikie Inlet and the mouth of Johns Hopkins Inlet (plate III) has a central core of Paleozoic meta- sedimentary rocks comprising hornfels, schist and marble which were metamorphosed during Cretaceous time. They are dominated and surrounded j s 7 j by Cretaceous granodiorite, quartz diorite and other granitics compri-j ! i i s sing a broad northwesterly igneous zone extending southward to Baranof; 9 j and Chichagof Islands, and northward through Glacier Bay and beyond. i 10 i| The Reid Inlet gold area within this Cretaceous zone of granitics ! 1 ! lies between the Lamplugh and Reid Glaciers and probably produced 1 2 between 7,000 ounces and 8,000 ounces of lode gold between 1938 and , 13 1950. Although the gold-bearing vein deposits are largely in the granodiorite and quartz diorite, marble, phyllite and argillite are vv i; also present at some of the gold properties. i 16 i The Paleozoic metasedimentary core of this province evidently is ! i i i? | not highly mineralized. Small contact metamorphic zones containing ; i | is j base metals, however, have been found within it east of Reid Glacier , i i? I in contact areas of a Tertiary pluton exhibiting a magnetic high. ', i ] 20 i Small amounts of gold have been reported farther north, east of Reid 21 i Inlet. , 22 j Another magnetic high occurs near the south end of the Paleozoics; J j "3 i in Cretaceous granodiorite and tonalite near Fourth of July Mountain. ' i 14 I No surface explanation for the magnetic high has been noted. C-193 9-1267 In the eastern part of this sub-province several localities exhibit stockworks of potassium feldspar veinlets in decomposed Cretaceous granodioritic rocks, but which do not appear to be associated with any! metallic minerals. Copper and molybdenum were especially looked for ! because of the possible porphyry molybdenum-copper environment. j A structural trench containing Brady and Lamplugh Glaciers and J passing to the west of the Reid Inlet gold area separates the grano- dioritics of the gold area from greenstone volcanics which appear to be ! a southeasterly extension of the rocks hosting the "Orange Point" typej ! 10 of zincrcopper deposit. Southeastward of the area of the greenstone volcanic unit/ as mapped, massive pyrite was encountered west of Lamp-* j lugh Glacier at two localities in mixed granitics and hornfels. These i | sulfides resemble those associated with the "Orange Point" deposit and may well bear further investigation, although the terrain is very rugged i 15 and largely snow-covered. j i 16 The Reid Inlet gold area is probably considered the most important i 17 area mineralogically in this sub-province. It is actually more exten 18 sive than might appear from claim locations, prospects and workings because, in addition to the gold found in samples from the rock mass between Lamplugh and Reid Glaciers, at least trace amounts of gold were found at nearly every locality sampled on the opposite sides of : 22 these glaciers. Gold has also been found in fairly high-grade but narrow subparallel veins on the northeast side of Russell Island. What lies to the south of the known gold area is under the Brady Ice field. C-194 i 9-1267 Reid Inlet gold area j i Introduction i i An estimated $250 thousand in gold, virtually all lode, was i ! I 4 I produced from the Reid Inlet gold area between 1938 and 1950 (MacKevett 5 !and others, 1971; and Rossman, 1959). The gold area's nucleus lies i i * {between Reid Inlet and Lamplugh Glacier (figure C-45) encompassing six ; 8 !Figure C-45 near here !______? ; I mines and about the same number of prospects within an area of less 10 ; |than 10 square miles. Gold-bearing veins, claims staked for gold, n i I and stained and altered zones found to contain traces of gold extend 12 into a much larger peripheral area probably covering a minimum of 60 13 i !square miles. Gold is clearly widespread within this region of Glacier u ! |Bay. 15- j !i Much of the gold produced in this area came from the LeRoy mine 16 , |during the 1940's. The Rainbow mine probably was a distant second. ;The history of the Incas, Monarch #1, Monarch #2 and Sentinal mines is '3 less clear and probably their production was less significant. ; Much of the foregoing and following information has been taken ~ 1 _ ' jfrom Territorial Department of Mines reports of visits to the area in T '. 11942, 1950 and 1954, and from U.S. Geological Survey publications 22 | !resulting from work done in 1954 and 1966 (Roehm, 1942; Fowler, 1950; «T ' ;Holdsworth, 1955; Rossman, 1959; and MacKevett and others, 1967 and 2-t i ;1971). Other works exist, most of whose information is incorporated -_ ; C-195 EXPLANATION Glacial ice and permanent snowfields Surfical deposits, includes glacial mo raines, alluvium & colluvium Biotite-hornblende tonalite and grano- diorite (Cretaceous) Metasedimentary racks (Cretaceous) Metosedimentary and metovolcanic rocks (Permian) Contact, generalized from plate I Fault, dashed where concealed Location of mine or prospect GLACIER Contour interval 500 feet mi. km. Base from U.S. Geological Survey, 163,360 Mt. Foirweother 0-3, 1961 Key to mines and prospects shown on map LRussell Island prospect (fig.C-55 ) a Sentinel mine !5.Whirlaway prospect 2.Churchill claim (location uncertain) 9.Monarch no 2 mine(fig.C-51 )l6.Rambler (Challenger) prospect 3.A.F Parker prospect (fig. C-58) IQMonarch no. I mine(fig.C-50)l7Highland Chief ( Joe's Dream) 4.Leroy mine(fig.C-46 andC-47) I Uncos mine (%C-49 ) prospect (fig.C-52 i Ptarmigan Creek basin l2.Sunrise prospect Site of LeRoy mill i Upper Rainbow prospect UGatena prospect 7Rainbow mine(fiaC-48 ) l4.Hopolong prospect Figure C-45 Reid Inlet gold area, mine and prospect locations 0196 9-1267 in the latter two reports cited. This information is supplemented by ; j | 2 'observations made and data gathered during this study. j ! ! 3 I The gold of the Reid Inlet area is in relatively small, discontinu- i j 4 Ious quartz veins and associated shear zones in metasedimentary and l 5_ [altered dioritic and granodioritic rocks. Virtually all veins i 6 isampled (1954, 1966, and during the present study) were found to be 7 gold-bearing. Many veins contained visible sulfides of iron, arsenic, 3 !lead, or zinc. Some of the veins from three properties (i.e., the 9 ] LeRoy, Highland Chief, and Russell Island) also contained traces of io_ i tungsten, however, in all instances below the 50 ppm numerical limit i n iof determination by spec. Although most veins based on the limited 12 ! sampling done were found to be of relatively low-grade, a few gave i 13 very high assays. Most veins were small in dimension, both in thick- u [ness and exposure length, although an occasional vein was up to four i :5_ i feet thick and some appeared to persist along strike for as much as 14 several hundred feet. 17 Gold was first discovered in the early 1920's by Joe Ibach in 13 float on icebergs which he traced to a Lamplugh Glacier source. He :? found gold in place in 1924. The monument was established by Presi- :o_ dential proclamation in 1925 and was opened to mining in 1936. The : - | production noted took place almost entirely between 1938 and 1950 i 22 ! although possibly small amounts of gold were produced both before and i 23 after that period. ;4 i All mining operations comprised selective mining of relatively ?c_ ; small vein deposits which were in nearly all instances steep-dipping ______^^^.^ ______C-19s*\ i <~i~j______/ " ______~~ 9-1267 to vertical. A small quantity of placer gold was reportedly mined, probably from residual concentrations derived from surface weathering of portions of gold-bearing veins. The total placer production is estimated to have been less than 100 ounces (Rossman, 1959). 5 i Although numerous gold-bearing veins are present in the area, and | | j i although they usually but not always occur in subparallel groups, ; ; their size, continuity, spacing and grade indicate that'any future I ' I 1 | mining operations considered will probably need to pursue the same i ' | type of largely underground selective mining on single vein systems 10 as has been done in the past. The steep dip of virtually all veins seen makes them more amenable to this type of operation than were 12 they gently dipping. None of the properties has adequate data for making reasonable or , i valid reserve calculations. With regard to the much less specific j 15 concept of resources, something more positive might be said. i 16 ij Exposures of outcrop throughout much of the Reid Inlet area as a whole !i i i 17 ! are good, and it is probable that most large important veins having ! '3 | surface exposure have been found. History of mining and exploration, 19 ! however, shows that veins have a tendency not to persist long distances, :o I appear to range widely in grade and width, are probably lens-shaped 21 I and usually lie in shear, fault, or altered zones nearly always | 22 ] steeply dipping. No obvious geologic reasoning would suggest the veins j j 23 i are either more, or less, persistent in length, width or grade along i 24 ! strike than they are in depth down-dip. Taking these observations and . reasoning into account, other similar veins may easily lie below the 9-1267 surface having no surface manifestation. Brief descriptions of some individual properties/ first mines then prospects, follow. Sketch maps of five mines and several prospects are presented in appropriate localities in the text. Localities of assay samples cut by the Territorial Department of Mines (TDM), U.S. Geolo gical Survey, and U.S. Bureau of Mines personnel are shown. Those of i the TDM were taken in 1954, USGS in 1966 and USBM during the present 1975-77 study. ' Results of sample assays and sample descriptions are given in ! i I tables throughout the text. i j LeRoy mine j i The LeRoy mine, situated two miles west of Reid Inlet and 3/4 j - ! mile south of the mouth of Ptarmigan Creek, accounted for most gold | I production from the Reid Inlet area. More than 600 feet of drift j { have been driven on three unconnected workings. The most extensive workings are on the LeRoy vein itself and comprise a 250-foot long , lower haulage drift at about the 950-foot elevation with a shorter ! discovery drift 35 feet above (figures C-46 and C-47). The vein has :: _ : Figures C-46 and C-47 near here I been stoped out between these levels and above the upper drift some 22 uncertain distance, except that at one point a stope is open to the ! surface about 70 feet above the lower level floor. Two-hundred feet to the northwest a 180-foot drift with an 807-foot raise explored a i ' smaller subpa ra, 1, ] eJ_veiiijgroup^._Alsc C-199 ®54-7 Cut at surface, O.i-.2ft. quartz 54-8 KI28 130 6KI32 - V*6KI3I Small veins at surface approximately 1.5ft. thick locally with a metamorphosed harse 0.5ft. thick OKUOle^oc, 0 5 10 20 j feet "o, meters VO u z 4 6 \ Contour interval 50ft EXPLANATION Slate,hornfels and schist, Black graphitic schist includes some intensely (Cretaceous) sheared granodiori te (Cretaceous) Contact, showing dip Fault, showing dip Vertical basaltic dike Basaltic dike, showing dip 90 _i =ajW Quartz vein, showing dip Dump Foot af raise I__ ] Ore chute Inclined workings, chevrons point 1^" Adit portol and open cut downward Open cut OOOOO Lagging or timbering along drift 54-11 X 66AMk-386 »7KO;J8 Location ot sample Location of sample Location of sample collected and assayed collected and assayed collected during the by the Territorial by the U.S. Geol. present investigation Department of Mines Survey in 1965 I I I r meters Assay data given in tables C-41 and C-42 0 10 20 30 Modified from MacKevett, 1971, plate 9 Figure C-46 LeRoy mine, west workings,sample locations C-200 Elevation app 950 feet Blacksmith shop an compressor house . X6KI33 Small veins at surface Quartz string O.I quartz Elevation \ app 987 feet % ^ . V /f'"' quartzr % '6K066-067 / -._ 0.7 Hquartz gtsurface" 0.3 ft quartz -333 vein at surface 7KO24 7K028 uartz less than 0.3 ...^ , mall quartz veins 66AMk-334 pen cut at surface 5K070.SK064 5K069 \ 66AMk-384 66AMK-385 66AMK-386 Modified from MacKevett, 197!, plate 9 Figure C-47 LeRoy mine,east workings,sample locations 0201 9-1267 stringers parallel the LeRoy system, 25 feet to the southeast of it, and have been explored for 40 feet by two open cuts and a short adit. The LeRoy system consisted of somewhat discontinuous quartz i veins following a sheared zone in altered granodiorite and metasedi- mentary rocks. The width of quartz reportedly ranged up to about 4^ feet at one point (Fowler, 1950), but averaged much less. Quartz veins at the LeRoy and in the immediate vicinity having significant gold values usually contain traces to conspicuous amounts of one or more of the following sulfides: arsenopyrite, pyrite, 10_ galena, sphalerite and chalcopyrite, often disseminated in bands or zones parallel to the vein. Some bands have a tendency to follow one -, 2 j wall. The better gold assays are almost always accompanied by high 12 lead and arsenic assays. | 14 j The LeRoy vein was discovered in 1938 by A. L. Parker and his I 15_ i son, L. F. Parker. Although mining was reported to have started i 16 I that year, most mining of the LeRoy vein was done by lessees in the 17 j early 1940's. By 1945 the ore above the lower LeRoy working level i ,3 had been largely mined (Rossman, 1959). Howard Fowler, an engineer i ? ; with the Territorial Department of Mines who mapped the LeRoy and i 20 ! subsidiary workings in 1950, stated that the vein had been completely 0 , i mined out above the lower LeRoy tunnel (Fowler, 1950). j 22 ! Total production from the LeRoy mine was probably between $130 22 j thousand and $170 thousand with gold valued at $35/ounce. It is not :4 : clear how much ore from other mines in the area went through the LeRoy i ,; i mill. Roehm (1942) reported that LeRoy ore averaged about $100/ton C-202 9-1267 (about 2.85 ounces per ton). Much of the production from this mine occurred in 1941 and 1942. The owner reports that overall production averaged about 3.3 ounces of gold per ton. The lessees of the LeRoy leased the Rainbow and Incas mines i : about 1945. Ore from at least the former was reportedly transported ; I I ; to Ptarmigan Creek and milled in the LeRoy mill. Rossman reported a ; i ! I production from the Rainbow of several hundred ounces. Milling | included crushing and grinding, and table concentration which produced! | high- and low-value concentrates. The high concentrate was run through Id- ! an amalgamation barrel to recover free milling gold while the low j j i -.1 j concentrate was treated by flotation to obtain an upgraded concentrate! ! 12 I for shipment to the smelter which contained most of the gold and silver. i I 13 ! According to the owner, about 25 percent of the gold was free milling.j u I During the present study, samples were obtained from the top of ; ! I i5 i the open stope, from open cuts on several veins, and from many of the J i ; I if j more than 15 parallel veins exposed on the surface in the immediate j i 17 mine area. Underground samples were also obtained from the main i 13 \ (east) workings and in the smaller west workings. Gold values ranged 19 i from nil to 25 ounces per ton. Nearly all were moil-cut channel samples 20- i taken across fairly narrow widths. The highest values were obtained 21 from thin veins at the top of the open stope. Some surface residual i ' :: ! enrichment may, or may not, have occurred. Assays, taken in October 23 1977 from underground in the main haulage of the LeRoy, are relatively --i low in grade and are mostly from thin stringers. These stringers ::_ i probably remain because the miners knew that the values were not high C-203 9-1267 .enough, or widths great enough, for those sections to be worth mining. Neither the very high assays in the top of the stope nor the I j unmined lower-grade parts in the main haulage can be construed to | j represent the mined tonnage. There is no evidence that mining occurred below the floor of the j LeRoy haulage level. The main vein was sampled on the floor of this ' i level in 1954 by Phil Holdsworth, then Territorial Commissioner of ! Mines. He was assisted by Darwin Rossman and Charles Ratte* of the i U.S. Geological Survey who were then fielding the work which le^d to j Rossman 1 s Bulletin 1058-B (1959). The sampling results indicated a ' i 50-foot strike length of vein exposure averaging about I3* ounces gold i per ton across an average two-foot vein width. By 1954 the mill had 13 been partly dismantled. Any further mining^ would probably have U required that the ore be hauled out and milled elsewhere. The main LeRoy vein appears to have pinched to a thin shear or alteration zone along the northwesterly wall of a thick basalt dike exposed in the face and adjacent back of 'the main haulage drift. The vein was reported to have met a dike in the upper drift as well. The 19 upper drift was not entered during this study. Samples of'the dike from the face of the lower drift and from a dike exposed on the surface to the south of the workings are petrographically nearly identical. They contain abundant augite, but are predominately composed of labradorite. A projection of the surface occurrence along strike and dip fits reasonably well the underground observations on the attitude of the dike.______C-204 9-1267 The dike underground differs from the surface occurrence only in that greater chloritic alteration has occurred in the ferromagnesi-i an minerals, and it seems softer and more friable/ perhaps partially due to blasting. Host rock is altered granodiorite. Assays of grab samples of the dike from the surface and from the face of the haulage drift yielded small amounts of gold (i.e, 0.002 and 0.005 ounce per ton/ respectively). The age of the dike relative to the quartz veining is not clear; however/ Rossman (1959) felt that the dike appeared to be older than 10 the quartz veining and may have acted as a dam for mineralizing solu tions. Continuity of the vein beyond the dike or lack of it has not been determined underground. Surface rubble of talus and glacial 13 debris obscure the dike and vein at the surface above the end of the drift. I ! 15 Figures C-46 and C-47 show slight changes from the mapping by 16 Fowler in 1950. Changes include an approximate five-foot extension 17 of the main haulage drift/ a breach of the dike 14 feet back from the face where it is five feet thick/ and the addition of a small open cut 19 on the vein swarm about 20 feet northeast of the open stope. These figures show the locations of all samples of which there is specific location record. These include samples taken by the owners, by Holdsworth in 1954, by the U.S. Geological Survey in 1966, and by the 23 Bureau of Mines during the present 1975-77 study. Results of assays ! of the first two sample groups are given in table C-40, while 25- sample results of the USGS and USBM are found in tables C-41 and C-205 9-1267 C-42. Descriptions and widths are also given. Tables C-40, C-41 and C-42 near here - The U.S. Geological Survey conducted a brief soil sampling campaign in 1966 in the immediate vicinity of the LeRoy mine (MacKevett and others, 1971) to determine whether lead in the soil could be picked up between 50 and 250 feet from known veins and used as an exploratory geochemical indicator to find other veins in the area. The method was concluded not to be satisfactory for the Reid 10- Inlet area. Twelve stream sediment samples were collected from Ptarmigan Creek below the LeRoy mine and mill drainage in 1976 by the Bureau of Mines. Only five contained detectable gold, and one any other u significant metal values. Virtually all were collected directly below mine and mill site drainages into the main creek, suggesting that stream sediment sampling is not necessarily a viable detection method for these gold deposits. Rainbow mine The Rainbow mine, probably the second largest producer in the Reid Inlet area, is situated about 15 feet above high tide on the steep bedrock shore of Glacier Bay about 2,500 feet northwest of the mouth of Reid Inlet (figure C-45). Six lode claims were located in 1936 at which time the owners were Joe Ibach and Newmont Mining Co. A short working was driven near the beach before 1940. The drift, C - 2 0 6 Table C-40 Assay data, LeRoy mine, Territorial Department of Mines [From the Alaska Div, Mines and Minerals (formerly Terr, Dept. Mines and Minerals) jn. MacKevett and others, 1971,table 12.] Fire assay Samples Length Ounces per ton Ft. (m) Su Ag Surface Samples 54-7 0.3 (0.1) 0 ,02 N 54-8 .5 ((*2) 2) 2 ,12 0.80 54-9 .5 10 ,34 7.40 54-10 .5 (.2) 1 ,37 L 54-11 1.3 (.4) .50 L Underground Samples 54-12 1.0 (0.3) 0.22 54-13 .3 (.1) .11 N 54-28 2.3 (.7) .38 L 54-29 4.0 (1.2) 2.63 L 54-30 .3 (.1) .25 L 54-31 .5 (.2) .10 N 54-32 .1 (.03) .46 L 54-33 1.0 (.3) 1.56 L 54-34 1.8 (.5) .42 L 54-35 2.0 (.6) .73 L 1 "7- (~2) .14 N 2 .36 N 3 (~2) .50 N 4 :5v .56 N 5 .42 0.60 6 (~2) .26 L ?7l/ 2.90 .66 i!o (.3) .16 N 1.5 (.5) .70 1.80 10 - 5/ .26 L I/ Selected sample. 2 Fines. 3/ 0.7-ft. section of drill core. 4_/ Location not known. 5/ Grab sample. C-207 Table C-41 Assay data, Reid Inlet gold area (nines and prospects (U.S. Geol. Survey) [From MacKevett and others. 1971. table 11.1 Atomic Semlquantltative absorption spectrographic cyanide F1re assay-atomic analysis method absorbtlon method Sample Type Length pom ounces per ton ounces per ton Description Ft. (m) Ag As Pb Zn Au Au LeRoy mine MK-326 Spaced chip, 1.5 (0. 5) N 20,000 N fl 0.0088 Quartz vein with minor 0.2-ft Interval horses. MK-328 Select grab N 7,000 N N .015 Represents the entire o width of a 0.3-ft wide to - quartz vein. 0 MK-329 do. N 15,000 50 N .029 0.058 Represents a 0.3-ft 00 wide quartz vein. MK-330 Channel .5 2 N 1,000 N N .012 Quartz vein, MK-332 do. .7 2 N 70,000 20 N .292 .450 do. MK-333 do. .4 1 N 30,000 N N .006 do. MK-334 do. 1.3 4 N N N N .0088 A 0.3-ft wide quartz veins 1n a 1.0-ft wide altered zone. MK-383 do. 1.3 (.4) 2,000 1,500 500 .321 .233 Quartz vein with subor dinate altered wall rock. MK-384 do. .7 (.2) 1.5 1.500 500 500 .495 .466 Quartz vein. MK-385 do. 1.0 (.3) 10 7,000 7,000 2,000 .350 .379 Quartz vein and altered wall rock. HK-386 Select grab 15 7,000 15.000 1.079 .699 Represents a 0.08-ft wide quartz vein and a 0.08-ft wide altered zone. Rainbow mine MK-387 Grab 1,500 70 0.116 0.205 Grab sample from ore pile near m face. MK-388 Channel 1.0 (0.3) 10 5,000 500 N 1.518 1.664 Quartz vein. MK-389 Grab - 10 1,500 300 N 1.635 1.606 do. MK-390 Channel 1.0 .3) 70 1,000 500 2,000 10.208 9.624 do. MK-391 do. 1.0 3! N N N N .0088 .0088 do. MK-392 do. 1.0 .3) N N N N .015 .0088 do. . Table C-41 Assay data, Reid Inlet gold area mines and prospects (U.S. Geol. Survey), cont. Atomic Semiquantitative absorption spectrographic cyanide Fire assfiy-atoralc analysis method absorption method Sample Type Length ppm ounces per ton ounces per ton Description Ft. Tin) Ag As Pb Zn Au Au Sentinal MK-393 Channel 1.0 (0.3) N N N N 0.117 0.0875 Near eastern-most outcrop of altered zone. Monarch no. 1 mine o to MK-337 Channel 2.4 (0.7) N N N N 0.0023 L Altered zone. o MK-339 do. .8 (.2) N N N N .006 0.012 do. MK-340 do. 1.3 .4) N 1,000 N N .012 .0088 do. MK-341 do. 2.0 .6 N 1,500 N N .006 .006 do. MK-342 do. 1.2 .4 N 1,500 15 N .029 .029 do. MK-343 do. 1.0 .3 N 7,000 100 N .029 .029 do. Monarch no. 2 mine MK-344 Channel 0.5 (0.2) N 2,000 10 N 0.026 0.0233 Quartz vein. MK-345 do. .5 2" N 1,500 N N .023 .017 do. MK-346 do. .5 .2 N N N N .0029 .0029 do. MK-348 do. .7 2) N 1,500 10 N .020 .023 do. East of Lamplugh Glacier MK-375 Grab N N N N 0.012 0.012 Pyrite-rich pod. Incas mine MK-350 Channel 0.8 (0.3) N 2,000 10 N 0.012 0.012 Altered zone. MK-351 do. 1.5 (.5) N 1,000 15 N .029 .020 do. MK-352 Spaced chip, 4.0 (1.2) N 20,000 N N .029 .029 do. 0.3-ft. Interval Sunrise prospect MK-572 Select grab' N N 0.0015 Represents 0.3-ft. wide quartz vein. Table C-41 Assay data, Re1d Inlet gold area mines and prospects (U.S. Geol. Survey), cont. Atomic Semiquantitative absorption spectrographic cyanide Fire assay-atomic analysis method absorbtion method Sample Type Length ppm ounces per ton ounces per ton Description Ft. ~7mT Ag As Pb Zn Au Au Hopalong prospect MK-57I Select grab N N N N Represents quartz veins. Rambler (Challenger) prospi o i Sj-5 Select grab N N 300 N 0.0015 Sheared and altered gran- to odiorite from contact with quartz vein (Sj-6). Sj-6 do. N 5,000 50 N .15 0.012 Represents 0.08-ft wide quartz vein. Sj-7 do. N 2,000 N N .204 .15 Sulfide-bearing quartz vein. Sj-8 do. N N N N .263 do. MK-545 do. N 30,000 30 N .029 Quartz veins, 0.08 to .3 foot wide. MK-546 do. N 50,000 N N .015 0.2-ft thick quartz vein. MK-547 do. N n N N L do. /.'»/- --/ '. I./ //(-,/ OWh/ fb'l £'0 utT w lov O'O ooow £0 JV OBO'O TV" ro II'O Ooz O/ -tro ZQO'O Z/'O oro OT-'O £'0 W'OI BO'0 Or,t 0/7 10V 01 vz owoti oo OI'O -r.ro o o O/'O /TV ro (X7/ oo/ II'O Z/'O Bh'O 5WO ZQ'O o bO'O £'0 oov QOV 00°) bt't oiy 17 M'O £0'0 ro -ZO'8 13'St XO'O CN 002/7 lh'0 I QQSI (>t'0 2-0 u ZO'V sro S'O Wvz O/ fV oos/ M'O fifV « oooo Lb'O -zro o QO^I /(V ~$v (UU) J89J \tv W f/0/ Table C-4£ Assay dataa#iA>Qff . -JdOULfLbduJ s cutdi ^ILO, C6>rf-, Analysis Sample .ength M AA Sample .Type Feet (m) Ax P? /\$ Description 0.3 0,030 /O 0,620 rr a 3 /o -can iKno Tr Hlf 5C 1KIV Th 1K112- /.o ft 30 T7- fAJ ^zfin L. -i x. uiora dfa it. haiuiOJP O.I OA5 Tr o K) I-1 N) IN 0,6 to A/ cT l MO/Mf 0-37 AJi 70 rhir^M A35" 100. AJ/I Mi/ t 36)0 1K035 an/i ^ rr ^ OD C 9-i267 f 1 now much enlarged, follows a foot-thick altered zone in granodiorite, ! ! f 2 |containing crushed vein quartz, for 180 feet to. where backfill blocks 3 iaccess to any further workings on that level (figure C-48). The vein ! 4 strikes about N30°E and dips steeply southeastward. The drift has j 5 j Figure C-48 near here ibeen stoped above the level for some distance. The extent of the a ' \ i stopes could not be determined because of the poor condition of the ! 9 j[Workings. Records of production are unavailable and size of the dump !'; I I 10 1 j ! cannot be used to gauge the extent of workings because the shore is too ! steep for a dump to accumulate . I 12 j I A considerable amount of high-grade ore was mined from the Rainbow ; 13 !"i , i workings, barged to Ptarmigan Creek, and hauled to and milled in the Le Roy 14 i ; | mill beginning about 1945 (Rossman, 1959) . The work was done under ' 15 j l I lease on the Incas property at about the same time. !6 ; i | The altered zone in which the Rainbow vein occurs is one of the 17 i : more persistent in the Reid Inlet area. It can be traced up the 18 ! mountainside to at least the 1,000-foot elevation. Some gold is 19 reported to have been recovered by surface mining near the upper end i (Rossman, 1959) . 2! . ' The two highest gold values obtained from underground samples by either the Geological Survey in 1966 or the Bureau of Mines during the 2: i present 1975-77 study came from the lower Rainbow workings, and were 24 i ' reported at 10.2 ounces and 7.9 ounces gold per ton, respectively. C-213 Elevation of portal app. 15 feet 70 0.3 ft. wide quartz vein in I ft. 0 5 1C) 20 wide altered zone. I,,,,, | feet 1 ' 1 i i meters 66AMk-392 0246 X/66 AMk-391 75 Altered zone app. I ft. wide, scattered quartz and much gouge 66AMk-390, 5K068 Altered zone app. I ft. wide EXPLANATION Granodiorite with minor alasKite (Cretaceous) ~J*\ Quartz vein, showing dip .»^r Vertical quartz vein Vein occupies altered zone 0.5 to 1.5 feet wide Timbered area ~v 0214 9-1267 Sample locations are shown in figure C-48. Sample data are given in tables C-41 and C-42. These values are from channel samples of 11.0 foot and 0.6 foot widths, respectively, cut across the vein in the i back both at approximately the same locality. Samples from the i iRainbow, particularly those having the higher gold values, are j generally also high in arsenic, lead and zinc as was found usually to i be the case at the LeRoy, Highland Chief, Rambler and Russell Island properties. In contrast, quartz veins in the A. F. Parker working i ;for example, although giving some high gold values across narrow (widths, indicated little or no arsenic present. i Geochemical soil sampling conducted by the U.S. Geological Survey ' i I ;in 1966 suggested that at the Rainbow as well as at the LeRoy mine i jlead in soils could probably not be used to trace gold-bearing veins. 14 Incas mine '5 ! The Incas mine was not visited by the Bureau of Mines during the ; | I :present study. Rossman (1959) and MacKevett and others:-(1971) indicate that some i i !200 feet of underground workings were driven, that gold values based on underground samples were relatively low, that although no production i records are available some production occurred probably mostly from surface workings, and that Rossman felt the property's possibilities as a mine remain unassessed. For the latter, subsurface physical 'investigation would be necessary. < Figure C-49, a sketch map of the workings, gives sample (localities. Results are given in table C-41. e ~C-4 9~near ~here~ C-215 o 5 10 20 j feet i r meters 4 6 o I Elevation of NJ H 66AMK- a\ portal app. EXPLANATION 1000 feet Granodiorite (Cretaceous) Hydrothermally altered fault zone "r^ro^" containing quartz lenses Location of channel or spaced 350 ch'p samP'e collected and assayed by the US. Geol. Survey in 1966 Assay data given in table C- 41______Modified from MacKevett, 1971, figure 14 Figure C-491 ncas mine, sample locations 9-1267 The Incas, found by Joe Ibach in 1924, was one of the first 2 prospects discovered in the Reid Inlet area. Claims were located in i 3 | 1936 by Joe Ibach and Rex Beach when the monument was open to mining. ! 4 ! When the workings were driven is not clear; however, the property was i 5_ | leased by the LeRoy Mining Co. about 1945 at the same time they leased 6 ! and began mining the Rainbow. i 7 I Monarch #1 and #2 mines s The Monarch #1 mine workings are situated at about the 1,900-foot i I 9 elevation west of Reid Inlet. Five Monarch claims covering this area 10 I were located by Joe Ibach and Rex Beach in 1936. Reed sampled a surface: 11 Ivein exposure in this general area in 1936, obtaining an assay of 0.97 i 12 ounce gold per ton and 0.50 ounce silver per ton across an 18-inch 13 iwidth (Reed, 1938). A tram from the 1,950-foot elevation to the beach n jexisted in 1940 and evidently some surface excavation had been done on '5 jone or more of the veins in the area. ii 16 | A group leased the property from Joe Ibach about 1945 and drove ! i "" .the 225-foot #1 upper underground workings over a period of about three i '3 |years. During this time they also drove the Monarch #2 adit-crosscut, 59 .about 400 feet lower on the mountainside, that consists of about 140 i 20 feet of workings. A tram joined the upper working with a road near 21 ithe lower working at about the 1,500-foot elevation. Another tram i 22 ]from the south end of the road passing over the Incas mine completed i 23 !the haulage system to the beach on Reid Inlet. The ore was transported 24 'to the beach, then taken to Lemesieur Island where Ibach had a two-ton C-217 9-1267 1 Gibson mill. The venture was considered to have been unprofitable i 2 |(Rossman, 1959). 3 | Figures C-50 and C-51 are geologic sketch maps of the two 4 (workings, showing sample localities. Three samples were taken in the 6 !Figures C-50 and C-51 near here 7 'Monarch #1 working by the Bureau of Mines during this study, while 3 ! .1 i10 others were taken both in upper and lower workings by MacKevett in 1966 '(MacKevett and. others, 1971). Assay values and descriptions of both groups 10- i ! I are given in tables C-41 and C-42, previously cited. 11 i i Underground assays from the hydrothermally altered fault zone in i 12 j !the upper drift and from the quartz vein exposed in the lower adit- 13 ' |corsscut range from less than .01 ounce to .03 ounce gold per ton. 14 i Although these assays indicate values remaining in the workings, they 15 i are not necessarily indicative of the grade of ore mined or of the 14 ; |grade of material that lead the miners to drive the workings at the 17 .' ionset. However, it was observed that only a small amount of stoping 13 had occurred in the upper working while none at all was observed in ;the lower. Some small production probably occurred from the Monarch claims, 21 a substantial proportion of which can probably be attributed to 22 ' i surface trenching along vein exposures perhaps other-than those on which the workings were driven. Rossman did not especially encourage "4 i ! future work on either of the structures developed underground. C-218 EXPLANATION elevation of portal Granodiorite (Cretaceous) app. 1875 ft. Hydrothermally altered fault zone, showing dip; contains open cut veins and lenses of quartz Quartz vein at surface 66AMK-343 66AMK-342 Location of channel or X 7K095 chip sample elevation app 1916 ft. 66AMK- samples were collected and assayed by the US. Geol survey in 1966. 7K-samples were collected during the present investigation. 66AMK-342, Assay data given in tables C-41 7K095 7( and C-42 elevation app. stoped 0 5 10 20 I....I I I f«' 1945 ft. I <1 I T meters 0246 66AMK-34I elevation app. ] 1968 ft. 66AMK-340, 7K094 elevation app. 1984 ft. 755 ^X\66Alv1k-339 position of fault_\ zone at surface elevation app. 1995 ft. 66AMK-337, 7K093 Modified from MacKevett, 1971, figure 12 Rgure C-50 Monarch no. I mine, sample locations C-219 EXPLANATION 0 5 10 20 Iniii I feet _L nr meters Grcmodiorite (Cretaceous) Mafic dike 66AMK-348 50 V*" Fault, approximately lo cated, showing dip o I ; elevation of tOl to, portal app. O 1500 ft. 8y Quartz vein between 0.2 66AMK-346 and 0.5 ft. wide, showing dip 66AMR-345 Location of channel sam- X pie collected and as- 66AMK-348 sayed by the U.S. Geol. Survey in 1966 Assay data given in table C-41 Modified from MacKevett, 1971, figure 13 Rgure C-51 Monarch no. 2 mine, sample locations 9-1267 I Sentinal mine The Sentinal claims located about 900 feet in elevation west of the mouth of Reid Inlet (figure C-45) were first held by Joe Ibach and Newmont Mining Co. in 1936 not far from the Rainbow structure, 5 i which they also held at the same time. i 6 I The description of the property is taken from Rossman (1959) and 7 ; MacKevett and others (1971). This property was-not visited by the i 3 JBureau of Mines. i i A foot-wide northwest-striking, steeply dipping hydrothermally 10 altered zone containing little or no quartz but sparse sulfides and secondary iron minerals mined by shallow surface workings was found 12 sloughed in 1966. It may have yielded a significant quantity of gold. Ore from this vein was carried to the beach and milled at Ibach's home on Lemesurier Island. 15 Ibach is reported to have had a two-ton Gibson mill on Lemesurier Island. There are a number of types of Gibson mills. Which type and 17 j what additional equipment Ibach may have had is uncertain. Both the :a i mill type and the percentage of gold in the ore that was free milling i i: | could greatly influence gold recovery. It is not known whether LeRoy :o ' ore chemistry is typical of the Reid Inlet area; however, most of the -n i LeRoy gold was tied up chemically, probably largely in lead and I 22 i arsenic sulfides. A channel sample cut in 1966 by MacKevett across a 23 j one-foot wide zone, one of several nearby having attitude and ii 2-'. i character similar to the Sentinal zone mined, contained no arsenic or I 25- i lead although it yielded 0.117 ounce gold per ton (table C-41). C-221 9-1267 Rossman, on the other hand, indicated that a red oxide (apparently a lead oxide) was present in some of the workings when mined, which suggests lead may have been present at the Sentinal. The production, although not recorded, may have been significant. j Highland Chief (Joe's Dream) prospect i | Six Highland Chief claims were located in 1936 just south of the | pass at the head of Ptarmigan Glacier, a mile west of the head of Reid ! I ! Inlet where gold-bearing quartz veins occur between elevations of I ! j 2,500 feet and 3,000 feet. The prospect has been relocated several ! ;i Ii times and is held by the six active Joe's Dream claims. j 10 i I According to Rossman (1959), the main vein not visible because of j ! i snow cover during his August 1954 visit was reported by Joe Ibach to be' in a gulch, to be up to six feet thick, and to contain a considerable ii amount of free gold. Rossman reports seeing other narrower, steep- j 15 | dipping northwest striking, gold-bearing quartz veins on the hillside east of the gulch. " ! i The property was visited by J. C. Reed in 1936, who described an altered zone containing four or five parallel quartz veinlets which were locally up to two feet thick. This zone was reported to pass under a small glacier to the south and to feather out in the country rock to the north. Strike was reported to be nearly north with a 21 steep westerly dip (Reed, 1938). A sample of typical vein material reportedly yielded 0.26 ounce gold per ton while the rock of the 24 altered zone yielded a trace of gold. The general prospect elevation 25 was given as 2,850 feet. C-222 9-1267 During U.S. Geological Survey field work in 1966 leading to Professional Paper 632, extensive snow fields covered the prospect and it could not be examined (MacKevett and others, 1971). During the present study the prospect area was completely snow-covered in August 1975; however, in August 1976 enough ground was snow-free that part of the easterly hillside could be examined. More area was snow-free in August 1977. A visit in October 1977 revealed other veins and open cuts not previously seen although much of the area was still covered by small snow fields. (The terms open cut, cut, and pit are used inter changeably in this section.) The relative positions and sample locations along veins and shear zones examined during the present study are shown in figure C-52, a map of the general area. Assays are given in table C-43. The central Figure C-52 and .table C-43 near here and southeasterly sections are mapped with bruton, tape and aneroid altimeter surveys. The northwesternmost veins and line of open cuts are joined with the Brunton survey by estimated and paced distances, and by generalized bearings that sometimes had to be estimated from photographs because there was not adequate time to sample or survey this area during the brief October 1977 visit. 22 Whether Ibach's large vein reported by Rossman was seen is doubtful. Either its locality was not specified accurately enough for it to be found, or it was rubble or snow-covered at the time of USBM C-223 X7KI22 0 100 200 [....I I I FEET onl >ETERS Contour interval 50 feet. AP.TS\ f>6K084 6K076,77,820\ .A-XX6K085 sloughed pit o Vx x^K086-87 EXPLANATION Altered granodiorite (Cretaceous) Metamorpnic rocKs, mainly marble Approximate contact Quartz or caicite vein O7KI2O ^^ Pft (°Pen c^i no* to scale, showing sample location \ K 6K090,7K080 ** Line of pits , nut examined due to \ 7K079 lacx of time x 7KII6 Channel sample location Assay data given in table C-43 7K070* Mapped by A. Kiniboll, October (977 Figure C-52 Highland Chief (Joe's Dream) prospect, sample locations 0224 Table C-43 Assay Chjilfr l/2- c/ Analysis OUNCE'S P0 2 01 il o Q. o O £ 00 Q 0 OQ p o _J m CA ~ . OJ a § T xi °\ & r & O i > S n- * i^> Q C O " <$T i. D" £ 3 § -Probable fault Rubble plane cover Granodiorite footwall EXPLANATION Rusty quartz vein Shear zone with quartz Crush zone and gouge Looking NIOW 0 .5 6K075i Channel sample location, j FEET 1 ' length to scale METERS 0 .1 2 .3 Horizontal and vertical scale Assay data given in table C-43 Mapped by A. Kimball, August 1976 Rgure C-53 Cross-section of pit no. one, Highland Chief prospect (Joe's Dream), sample locations C-227 9-1267 Three open cuts exposing short portions of a sheared and altered zone containing several subparallel quartz veins (shown in the west- central part of the figure C-52 area) were sampled in some detail, as the elevation and general characteristics of the zone correlate with 5 ; Reed's 1936 description previously given. It is, however, not known 4 |whether this is the quartz vein bearing altered zone described by Reed, j i i 7 ,Figure C-53 gives cross-sectional detail of the largest of the open cut : 'Figure C-53 near here 10 exposures. Remains of tool handles and a rusty gold pan were found in i a nearby cut. Open cuts expose the quartz veins and shear structure 12 j I for at least 150 feet. The steeply west-dipping, approximately north- 3 ! Istriking structure disappears under a snow field to the south .and fin- * i .gers into the country rock to the north, quite similar to Reed's is ; Description. 16 Several other sheared or altered zones and veins were sampled and, in all, nearly 40 samples were obtained, nearly all channel cuts. Sample widths range from 0.2 feet to 4.5 feet while gold assays range from nil to 3.49 ounces per ton; the latter, sample 6K090, was taken lacross an 0.3-foot width. The line of prominent open cuts in the northwesterly part of the 22 :area shown in figure C-52 between elevations of 2,900 feet and 2,975 | ifeet, snow-free only during the brief visit in October 1977, clearly had considerable work done on it. There was not time to examine the 25 C-228 9-1267 , lower pits to the south along this prominent structure; however, [ 2 samples were obtained in and near the two uppermost pits. Here, the I 3 best combination of width and grade ran 0.19 ounce gold per ton across 4 a 2.6-foot width of vein in a four-foot deep open cut. Wood fragments j | i 5_ iwere found near several of the cuts. i i ! 0 ; Rossman (1959) noted on his plate I the symbol "x" at several 7 llocalities in this general prospect area. One, perhaps the largest, is ; a jshown in the center of the gully draining south from Ptarmigan Pass. : i i 9 At about this locality (approximately 2,650 feet in elevation), a 10- i j 10 ifoot by 25-foot old camp site on the alluvial slope was found, compris- ! ! i 11 |ing a level area surfaced with fine material built up behind a dry wall i , 2 jstrewn with tin can remnants, coal fragments, and some pieces of . I \ 13 'mineralized vein quartz. An apparent trail leads from this general ' j£ ' u area up the easterly side of thegully, partly obscured by snow, toward ; /\ it i5__ JFtarmigan Pass or the open cuts noted above. - i , 4 ; The "main" vein described by Ibach may have been in the camp site 17 'area; however, no rock cropped out in that area of rubble cover and i ', -, s 'patchy snow. , 19 i Newmont Mining Co. took a lease on the Highland Chief and Rambler i 2c_ Iclaims in 1937 and, according to Rossman (1959), spent several months ; i 2 , 'looking over, mapping and sampling these prospects as well as others 22 I in the Reid Inlet area. He reported that the lease was dropped because 23 iof the inaccessibility as a deterrent to the mining of these vein 2-4 i systems. ' 25 C-229 9-1267 The Highland Chief is probably more accessible now that it was in \ 1 1937 because of Reid Glacier recession since then. On the other hand, j i I isnow and rubble probably obscured important veins that could therefore j I i not be sampled during the present study. Those veins seen appeared to i i be more persistent here than veins in most other parts of the Reid I ;Inlet area, also noted by Rossman (1959). i i Rambler (Challenger) prospect ! Four Rambler claims located in 1936 covered a conspicuous quartz 9 Jvein system exposed in the head of a steep gully near the 1,850-foot i 10 I elevation overlooking the Lamplugh Glacier (figure C-45). The locality j 1 iis about one mile due south of the summit of Mt. Parker. Since 1936, 2 ithe prospect has been variously restaked and is now held by the two i 3 {active Challenger claims. i 4 I The main vein system, made up of several subparallel probably i5__ i interconnected veins of slightly iron-stained pyrite and base metal i i 6 'sulfide-bearing quartz, is approximately vertical and strikes easterly. I 7 |It is exposed for possibly 100 feet in a steep-to-vertical cliff and 3 ;has a maximum thickness of about six feet where several narrower splits 9 ijoin. The vein system passes under gully rubble downward to reappear ,:__ ' 35 feet below, and has an intermittent slope exposure length of more , I than 200 feet. Upward it disappears in a cliff. No attempt was made t 22 to scale the cliff. '< Seven channel samples (6K108-111 and 6K187-189) cut across widths .of from 0.3 foot to 4,0 feet along the vein system and its offshoots C-230 9-1267 gave assays between nil and 0.16 ounce gold per ton. The highest value was across a one-foot width (table C-44). Table C-44 near here I - Two veins about 400 yards south cut the same altered granodiorite j ' ! i I host. They were sampled at the 1,850-foot elevation a year earlier i i (samples 5K102-105) and thought to be the Rambler when, in fact, the ! 3 i ! Rambler proper was then probably snow-covered. The highest assay 9 ! jobtained was 0.58 ounce gold per ton across a 0.25-foot width 10- I 11 ii of quartz vein in gully float. It is probable that the float came ! i from a visible, but inaccessible, vein exposure in the cliff above. ! 12 | i | A nearly one-foot thick vein associated with a short breccia zone 13 i I 160 feet N25°W of the thickest part of the main vein system and at u | i about the same elevation can be traced in a vertical exposure for about 15- | ! 30 feet. It disappears beneath rubble down-slope to the west. A . i I* ! i channel cut across a 0.9-foot width assayed 1.785 ounces gold per ton '' ;7 I ' iwhile another 0.35-foot width, representing a high-grade sulfide-rich 53 ' part near the 0.9-foot cut, assayed 6.45 ounces gold per ton (samples "9 ; 1 6K191 and 192). i ; The extent of this vein, and the grade except near where sampled, : I has not been determined. Prorated across a four-foot mining width ;' 22 ! ; ; and based on the very limited sampling done, grade at the points 23 : sampled would range between 0.40 ounce and 0.57 ounce gold per ton. C-231 TV" IT7 u '0 f rv /TO fV 80 -O £0 v "VT0 ( "7 OL'O Or '0 o y WWQOO'l t,L°\ opbr? oo4ri oofs LI' b'O JG- OS O/- SOO'O h'f O'f 02to' 01 N £'0 UT); OOL -It ty Q' Oh' QOJtl OT 50 '0 £'( / i?\f ; £'0 001- O goo'O CM O7 Of 01 n ON TO'O i' S'O I U n jj. L'O giOfM^. or L'Z OTOT 10^ ZI'Q LfT>f I? /;>?_ oro 20 Of N N S'O OOl- CV I' irui/vtp UO|jdjJOS8Q V""W"W (Ui) J88J SISA|DUV 9-1267 The Geological Survey took seven select grab samples from the area of Rambler prospect in 1966 (MacKevett and others/ 1971). Assay values and sample descriptions are given in table C-41. Galena prospect The Galena prospect near an elevation of 500 feet on the west side i i of Reid Inlet (figure C-45) was reported by MacKevett (1971) to have ; been obscured by sloughing and overburden in 1966. It was reported to ! I be a 4-inch to 18-inch thick, 60-foot long pyrite, gold and base metal ' 1 sulfide-bearing vuggy quartz vein in dominantly granodiorite rocks ' I 10 (Twenhofel and others, 1949) . Mining records show that the Galena claim was recorded in 1937. ! S ! ! Reed (1938) collected a sample during a 1936 visit which evidently i i I ! came from this vein or one near it, and which assayed 0.16 ounce gold per ton, 0.30 ounce silver per ton, and 0.79 percent zinc across a 12- j 15 !inch vein width. A small production is reported to have occurred in 11939 from this prospect (Twenhofel and others, 1949). Sunrise prospect Eight Sunrise claims and two Sunrise Extension claims were located by Joe Ibach and Rex Beach on the east side of Reid Inlet in 1936. They extended from the beach to at least the 800-foot elevation and probably higher (figure C-45). A sample cut by Reed (1938) in the vicinity was reported to carry 0.08 ounce gold per ton across a 10-inch width of quartz vein ranging in width from -two inches to 18 inches. None of the veins in the vicinity were reported to be treceable for more than a few tens of feet. C-233 9-1267 ij 1 j MacKevett and others (1971) reported negligible gold values from I 2 i samples cut in the general area in 1966. i 3 j No evidence of claims or workings were found in the vicinity by 4 the Bureau of Mines during the present study although reconnaissance ! ! 5-i was made between the elevations of 200 feet and about 1,400 feet. A j I 6 i number of small quartz veins, a quartz-calcite vein, and a very \ i i! 7 i conspicuously red-brown stained zone in dominantly calcareous host i ; 3 ! rocks were sampled. The quartz-calcite vein at the 550-foot elevation j i | 9 | contained a trace (about 0.05 ppm) of gold, otherwise samples yielded i | | ic no detectable gold and negligible values in other metals. A. F. Parker prospect The A. F. Parker prospect located in 1938 consists of a 16-foot i I 13 {drift at the 1,000-foot elevation about 3,300 feet (5/8 mile) westerly i u j from the LeRoy mine (figure C-45). The drift was driven S65°W on a i u | gougy shear zone containing a narrow quartz vein that may be faulted i i6 | off at the face by two faults (figure C-54). A remnant of the vein and '3 ' Figure C-54 near here part of the gouge zone were sampled (table C-44). Little of the vein 20 : apparently remains and neigher direction nor amount of fault movement 21 ; can be ascertained from the evidence at hand. The sample of the vein 22 ! j and gouge in the face along fault #1 assayed 0.09 ounce per ton while 23 ; ! an assay of the vein itself was slightly less. A sample of a 0.1-foot 24 : wide vein from material on the dump assayed 2.27 ounces per ton and C-234 Cross-section of face of adit looking S65W Elevation of portal app. 1000 ft. Sample 6KI83 located on knob 35 feet Southwest of portal Fault no. 2 truncates Fault no. I Maputo by A Kimball, Auflutt, 1976 Explanation Altered granodiorite .*_*._ Shear zone n (cretaceous) -s--r£ _»_»- Vertical quartz vein - -^ Fault, showing dip Portal with open cut XN ' ''l. Dump i 6KI80 Sample location Assay data given in table C - 45 Figure C-54 A.F Parker prospect, sample locations C-235 9-1267 may be indicative of vein material removed. An aerial tram reportedly 1 connected this working with the beach in 1940 (Twenhofel and 3 |others, 1949). j i A grab sample of quartz from the face near the back along the "cuty | 5 ioff" fault assayed 5.13 ounces gold per ton indicating that gold values! i | 6 are spotty. Search of the immediate area of the workings revealed a i 7 thin vein in a nearby bluff about 35 feet higher than the portal s :i elevation. A sample of this vein across its 0.1-foot width assayed i' i ! 9 i 2.46 ounces per ton. Rock exposures, where not practically vertical, ; ! i !o_ i were covered by rubble and vegetation obscuring this vein's relation- : n ' ship to the vein in the workings, if any. No other veins were noted in' i i 12 j the area of the workings; however, others could easily have been ! i 13 i covered by vegetation and rubble. i u | Hopalong prospect i 5- ! The Hopalong claim located by Joe Ibach in 1943 was reported to i6 ! be a mile east of the face of Reid Glacier at that time (figure C-45). ir | According to Rossman (1949), the claim was staked at an altitude of is about 1,350 feet and small amounts of gold were recovered by sluicing 19 ; weathered parts of the veins. ;D- ; Quartz veins up to a foot thick cutting diorite rocks and 2; ! traceable for as much as 60 feet along strike were reported to contain I 22 i calcite and uncommonly pyrite and arsenopyrite (MacKevett and others, i3 : 1971). A grab sample from the veins collected in 1966 by MacKevett 2-s ! was reported to be virtually barren of gold value. C-236 9-1267 These veins, although briefly looked for during a Bureau of Mines traverse in the area, were not seen during the present study. i Whirlaway prospect j Four Whirlaway claims were staked by Joe Ibach in 1944 on the west 5 side of Reid Inlet,' beginning 1,000 feet northwest of the face of Reid 'I 6 J Glacier, according to courthouse records. Three were end-to-end along 7 shore (figure C-45), and at least in part probably lay shoreward of a | the Galena prospect and may have included it. This area is mantled i 9 j by moraine and talus, and was not investigated during the present i 10 study. i i 1 Mt. Parker area i The crest of the Mt. Parker ridge was traversed from a point ; i 13 opposite the Highland Chief prospect for more than three miles to a ' point opposite the A. F. Parker prospect in search of quartz veins ' 15 which might have been missed during past prospecting effort. Eleva- 16 I! tions ranged from" 1,700 feet to 3,600 feet, and broad sections ! 17 covered with snow fields could not be inspected. One fairly prominent , | . ! is ! vein was found that passed under rubble to the west and over a cliff i "> i to the east. Assays of samples from two localities 100 feet apart i ! 20 ; yielded 0.94 ounce gold per ton for an 0.8-foot width, and gave nil for 21 ,i a 1.0-foot width by fire assay. Other veins may have been covered by ' i 22 snow or extensive areas of rubble cover. The vein seen is roughly i I ; 22 i aligned with those sampled and previously described as being situated i 2-) | about 400 yards south of the Rambler. However, the veins south of the 25- Rambler probably do not extend as individual veins this far. The two C-237 9-1267 areas of veins may lie along the same structural feature or parallel ones. Elevation difference between these two sites is about 1,200 feet Russell Island gold prospect The Russell Island prospect is located on the northeast edge of 5 Russell Island and consists of narrow gold-bearing quartz veins in an | iron-stained zone up to four feet thick in Cretaceous granodiorite. 'The location is shown in figure C-45. Previous investigation of this i , ,. . .,^». ,..,. - ' area by tne Geological Survey (MacKevett and others, 1971) in 1966 reported the zone as traceable for 25 feet and reported that a select grab sample of a narrow quartz vein contained 0.844 ounce of gold per ton. The present investigation found the north portion of the altered or iron-stained zone that forms a shallow depression in the'granodio 13 rite host traceable from tidewater to brushy cover, a distance of 40 feet. It was traceable through brush and cover, a distance of 100 ! | feet, via the depression it forms and thence to the other side of the ; i small peninsula where it reappears from under rubble and cover, and is ; traceable for another 20 feet to rubble at the tide line. This zone has an estimated length of at least 280 feet, strikes N15°E and has : a vertical dip. Figure C-55 is a map of the zone showing sample 1 locations. 22 Figure C-55 near here 23 The iron-stained zone consists of hydrothermally altered grano diorite (chlorite, sericite, introduced quartz) containing several ankerite, , '.?, i~. H'Jjb.i:-1 GPO -C-238 Glacier Bay approximate position of C shoreline at high tide 6S040E 6S070-7I r> 6S040^2, : 06^-69 Location Map Elev. 16 ft o 0.5 i I . i I 100 feet of cover I I l T Kilometers *o p.5 i 1.5 contour interval 100 feet i E X PLANATION Biotite-hornblende granodiorite Elev. IO ft. (Cretaceous) Iron-stained biotite-homblende granodiorite with occasional sulfides 6S068 Vertical quartz vein, locally with disseminated sulfides £5067 ' 7 y Chip sample location, length 6S069 to scale 6S06 A6S066 Channel sample location 6S066 or 6S065 6S040B-" approximate position of Assay data given in table C-45 shoreline at high tide Glacier Bay 5 10 , j____I feet I meters Mapped by J Still, August ore Figure O55 Russell Island prospect, sample locations C-239 9-1267 pyrite, pyrrhotite, sericite, dolomite, calcite and traces of scheelite. Metallic gold was found in the pyrite. The zone was sampled at several locations. Table C-45 gives analytical results. Channel samples of the narrow quartz veins Table C-45 near here contained up to 5.81 ounces gold per ton and 2.64 ounces silver per ton. In addition to gold and silver, the zone contained up to 890 ppm lead, 550 ppm zinc and detectable tungsten below the limit of numerical determination which is 50 ppm. Average weighted values across a four foot mining width range from 0.35 ounce gold per ton and 0.17 ounce silver per ton (sample 6S040) to 0.02 ounce gold per ton and a trace of silver per ton (sample 6S065 and 6S066). Although not of commercial grade or size, its persistence along strike and indications of high gold values are encouraging. Substantial increases in the price of gold might encourage further exploration. It could be mined from a shaft if substantial barriers were left on the sea side. Two additional narrow, iron-stained zones in granodiorite are exposed along the east shore of Russell Island about 1,000 feet north of the zone shown in figure C-55, and contained 0.30 ppm and 0.15 ppm gold (samples 6S070 and 071), a trace each had they been run by fire assay. Additional exploration of the iron-stained zones along the east side of Russell Island may be warranted. C-240 £ & '-£P J tf i ?-» ( Is V) I'J O o OC 0 Is L. O CU C5 C Vo ^ lo CXD ^ Z? 0 O O. V) \n a Vr re n o ^ V) O C5 o c3 r±3 0 ^ C-241 9-1267 Ptarmigan Creek basin A placer claim was located in 1974 in a basin on Ptarmigan Creek ! i about 7,000 feet from its mouth. The basin lies between 1,000-feet ! i and 1,150-feet elevations and covers probably 30 acres to 40 acres | (figure C-45). Alluvial fan material probably largely glacial in origin with some colluvial material along the edges comprises the basin floor. Altered metasedimentary rocks are in place 100 feet below a falls at the head of the basin; otherwise there are no bedrock exposures in the area either seen or likely to be found. A 10 low barrier at the mouth of the basin breached by the creek is probably at least in part glacial moraine, either a terminal or 12 recessional moraine related to a former front of Ptarmigan Glacier or a laterial moraine associated with a stage of much more extensive glaciation to the north, now receded. The latter is most likely and is probably also responsible for the extensive glacial deposits . between the LeRoy mine and the beach. Much of Ptarmigan Creek below the 1,500-foot elevation was located in placer claims in 1976 by the LeRoy mine owner. Some, possibly all, of these claims are active. During the present study the basin previously described was inspected for the possibilities that placer gold deposits might exist there. There is no evidence of mining activity and none is / known to have occurred. A few colors were panned from a stream -242 9-1267 channel following the west margin of the basin and from material on the surface of bedrock below the falls at the head of the alluvial fan. Little or no sorting of material is evident anywhere. Grading 5 of boulders to smaller-sized material with an increasing percentage of fines progressively downstream is evident through the basin; how ever, much very coarse material is present throughout. Boulders several feet in diameter are common in the upper part of the fan while those up to six inches' to eight inches in diameter are common 10 near the lower end. / - Bedrock reportedly exposed in the stream bed above the falls at the top of the basin was obscured by rubble and snow at the time of 13 our visit except for that which formed the wall of an inaccessible canyon through which the large stream-flow prevented access. Assess 15- ment near bedrock could not be made. 16 Alluvium in the basin below was sampled as a lower priority 17 alternative. Surface samples were taken in lines crossing the 18 basin. Samples were obtained at 100-foot intervals from a random start in two lines normal to the valley (stream) trend and about 800 feet apart, and centered roughly between the falls and the lower 21 outlet barrier. The lower line (#1) comprised nine samples and the 22 upper (#2) eight. Each sample was made up of fines collected by 23 shovel or by hand from between boulders to fill a 14-inch gold pan, 24 thence panned down to a sample weighing between five and eight and 25 one-haIf pounds. C-243 9-1267 These samples were laboratory-panned to a concentrate that was i 2 ! fire assayed. Tailings from six samples (of the 17) , randomly selected-, ! i were amalgamated. A cut of the tails of all samples was fire-assayed and values combined to single values for each total sample. Samples :_ ; do not represent fan material as a whole, but may represent on a recon- j 6 naissance basis randomly selected fines collected from near the present I i 7 \ surface of the fan. j s i One sample had a numerical assay value of 0.001 ounce gold per ton iI ,i ? ! or about 15 cents/ton with gold valued at $150/ounce, while two others : j j 10- I contained .00006 ounce per ton and a trace (only a few percent of that j i j I i 1 i numerical value) . No gold was detected in any of the other samples. ' ! i 2 ^ Fire assay assesses total gold but not free milling or necessarily I i 3 ! recoverable placer gold so results may be more, but will not be less, - i x i 4 i than what might be recovered in placer mining. | i i 5__ A row of 20 stream sediment samples was taken across the basin on ; ! I 6 ; 50-foot intervals from a random start in 1976 near the sample line #1 . ! 7 : locality. Gold assays run by atomic absorption on the minus 80 mesh 3 l fraction were all below the lower limit of qualitative detection (i.e,, 9 '' all were below 0.05 ppm, 0.0014 ounces per ton), or below about 21 20- i cents per ton with gold valued at $150 per ounce. The sampling i ; methods using larger samples gave much more sensitive gold determina- i : iI tions than the stream sediment sampling method. : I Possibly some higher values lie on or near bedrock above the « falls, but determination of values is dependent on accessibility. i rs- ; Steep topography, bedrock rubble cover, snow cover until late summer, C-244 9-1267 and unmanageable stream-flow are deterrents difficult to surmount in making an assessment of this area. There is no sure way to assess what may lie under the Ptarmigan Glacier in terms of gold-bearing veins which may be slowly physically 5- ! abrading and releasing potential placer gold; however, if gold is being released, it seems that at least some should have been picked up in i the reconnaissance samples of the alluvial material on the surface of i i i the fan. 1 i Conclusion 10 Based on previous work by Rossman (1959) and MacKevett and others (1967 and 1971) regarding the Reid Inlet gold area as a whole, 12 and on more specific work by Reed (1938), Twenhofel and others (1949), Roehm (1942), Fowler (1950) and Holdsworth (1955), and on observations | u made during the present study by the Bureau of Mines, some conclusions 15 i about the Reid Inlet gold area can be drawn. | 16 | There are numerous exposed altered zones in which gold-bearing 17 | veins occur intermittently, and there is no geologic reason why veins i la | do not occur at depth as well as exposed at the surface. All zones 19 i are steep-dipping and most strike roughly north, northeast, to east. 20 i Rock exposures are such that probably most prominent zones having 21 surface exposures are known; exceptions to this are those that may 22 lie beneath low altitude glacial detritus, under snow fields or under i 23 ! the Ptarmigan Glacier. Most veins are less than three feet wide and 24 i few can be traced for more than a few hundred feet, although the zones 25 i that contain them may sometimes be traced for much greater distances. ! 0245 9-1267 Two vein systems, the LeRoy and the Rainbow, have had significant production. Several other vein systems have produced small amounts of gold, but unfortunately records are not available to establish how much. Most veins are small and discontinuous, range widely in width, and contain spotty gold values. Veins appear to be lenticular and of limited strike length; however, geologic reasoning suggests their down-dip lengths are as great as their strike lengths, and width ; i and grade variations would be no greater down-dip than along strike. : I 10- These characteristics combined with relatively wide spacing indicate ' \ j ! that any future mining is likely to be similar to the operations which j I have occurred in the past. . I i ! i ! Data are probably not adequate for reserve calculations -on any of : 1 the properties or for broader resource estimates. ' i ' i Remainder of province i 16 j The Churchill claim was recorded by Terry Richtmeyer in 1964 j as 1,200 feet south of "Reid Inlet" and about two miles west of 1i : Ptarmigan Creek (figure C-46). The commodity sought is uncertain, and the claim was not found during this investigation. Twelve localities to the east and south of the Reid Inlet gold area ' are briefly covered in table C-46 which follows. Their positions are , shown on plate III. i Several other localities to the west, beyond Lamplugh Glacier, are discussed in a similar table accompanying the North Geikie province text because they may be geologically more closely allied with deposits in that province. 'C-246 Table O-4d. Middle Geikie subprovince, occurrences not discussed in text. No. on Name of Main Source of piate III prospect commodity Location Description of deposit Mining claims information Remarks 47 South end of Mo South end of Iron-stained altered zones None recorded. A random chip sample ta MacKevett, 1971, the Parker the ridge bet occur in metamorphic rocks ken for IS ft. across an p. 79i location nunatak. ween Reid and near a contact with grano- irregular iron-stained no. 70; this Lamp1ugh Gla dioritc. Small pods of altered zone contained a investigation. ciers at an massive pyrite a few trace of Au (AAS analy elevation of tenths of a foot long arc sis) and 10 ppm Mo. Two 3,300 ft. present in marble layers spaced-chip samples taken in the altered zones. A for 9 and 27 ft., respec O few quartz veins between tively, across a similar to 0.5 and 4.0 feet wide zone each contained 5 ppm occur in some of the Mo. MacKevett (1971) zones. reports that a 5-ft. long chip sample taken across an altered zone contained a trace of Au (AAS analy sis) and 7 ppm Mo. East of Reid O» Kast of the di Quartz veins between 1 None recorded. MacKevett (1971) reports Mackevett, 1971, Glacier- vide between and 2 ft. wide contain that a uelect grab sample p. 52, location Reid and Scid- ing small amounts of from the a)tered Rones no. 69. more Glaciers sulfides occur in meta contained a trace of Au at an eleva morphic rocks, mainly (AAb analysis) and 300 ppm tion of appr. marble. Two iron- Cu. A sample of a quartz 4,000 ft. stained zones, each 10 vein contained a trace of ft. wide, also occur in gold (AAS analysis) and the metamorphic rocks. 1,000 ppm Cu. 49 Kast of the Au blast 'of the Pyrite occurs in a 7-ft, None recorded, A chip sample taken for 7 This investigation. head of Held head of Reid wide iron-stained zone ft. across the stained Glacier. Glacier near in nor life Is and marble. zone contained a trace of the head of gold (AAS analysis) and 5 Scidmorc Gla ppm Mo. cier at an elevation of 4,000 ft. Table C-46. Middle Geikie subprovince, occurrences not discussed in text, con't. No. on Main I/ Source of plate III commodity Location Description of deposit Mining claims Samples ~* information Remarks 50 East of the Cu East of the Banded suIfides comprising None recorded. A composite grab sample This investiga head of Reid head of Reid pyrite, arsenopyrite and of a pyritic zone a few tion. Glacier Glacier near chalcopyrite occur in iron- tenths of a foot wide the head of stained epidote-garnet contained a trace of gold Hugh Miller skarn, Sulfide-rich zones (AAS analysis), 15% Fe Glacier at an are up to 3 ft. in width. and greater than 5,000 elevation of ppm Mn. A grab sample 4,100 ft. from a 3-ft. wide stained zone with massive pyrite O contained 0.15 ppm Au, 730 I ppm Cu (both AAS analysis), to *. 1.5 ppm Ag and greater 00 than 20% Pe. A chip sample across a 2.5-ft. wide stained zone contained 1,100 ppm Cu (AAS analysis), 1.0 ppm Ag and greater than 20% Fe. 51 Gilbert Island W North of the A 1-ft. wide tactite zone None recorded. MacKevett (1971) reports MacKevett, 1971, _ summit of Gil occurs in marble. that a select grab sample p. 83-84, loca bert Isl. at contained 150 ppm Cu and tion no. 43. an elevation 150 ppm H. of 2,000 ft. 52 Blue Mouse Cove Pb, Northeast end Twelve-foot wide shear None recorded. A MacKevett (1971) chip MacKevett, 1971, These two Zn, of Gilbert zone adjacent to ande- sample at 3-inch inter p. 50, location zones are Ag Isl., north site dike in quartz vals taken across the no. 42) this probably of Blue Mouse diorite and granodio- richest looking 2 ft. of investigation . separate, Cove. rite noted in 1966. the 12 ft. zone contained but in gene In 1977, a probably 700 ppm Zn and a trace of ral vicinity separate, remarkably Ag. A 1977 continuous of one straight vertical chip across 2.5 ft. of the another . Table C-46. Middle Geikie subprovince, occurrences not discussed in text,,con't. No. on Main Source of plate III commodity Location Description of deposit Mining claims information Remarks 52,cont. N75°E shear zone was found 4 ft. zone yielded simi cutting hetrogeneous ig lar values, i.e. 680 ppm neous rocks. Width 4 ft. Zn (AA), 220 ppm Pb (AA), where visited. Length ap 7 ppm Ag(spec),and 3,000 pears to continue up moun ppm As. A second sample tainside for greater than 200 ft. northeast had 1000 feet. lower values. O 53 Southwest end Cu ( Minor copper and molyb None recorded. Only minor concentrations MacKevett, 1971, of Gilbert Mo denum occur in shatter of copper and no molyb p. 41, 50, 55, Isl. zones in bleached quartz denum were detected in 2 73, 74, location V£> diorite. The mineraliza- channel samples from no. 45; Rossman, tion is localized along quartz veins and in 5 1963b; some of the borders of spaced-chip samples tak this investiga the numerous quartz veins en across the shatter tion. and stringers which occur zones. MacKevett (1971) as stockworks. A few reports that a select aplite dikes cut the grab sample from a 0.5- shatter zones and potash ft. wide quartz vein con feldspar is present in tained 1,000 ppm Cu. A irregular seams and float sample of quartz blebs. The mineralized contained 0.292 oz. Ag/ton, zone is exposed for about 7,000 ppm Cu and 2,000 ppm 1/2 mile along a beach Mo. at tidewater.' Some zones in the quartz diorite are iron-stained. 54 Southwest end Cu, Isl. south of Minor pyrite occurs in a None recorded. A channel sample taken MacKevett, 1971, of Gilbert Mo southwest end bleached and fractured across a 0.8-ft. wide p. 41, 73, 79, Isl. of Gilbert Isl. zone in quartz diorite shear zone contained no location no. 44; that is about 1,000 ft. significant metal values, Rossman, 1963b, long. A few alaskite and MacKevett (1971) reported p. k50> this Table C-46. Middle Geikie subprovihee,,occurrences not discussed in text, con't. Main I/ Source of commodity Location Description of deposit Mining claims information. Remarks 54, cont. aplite dikes cut the zone, that two select grab sam investigation. and thin quartz veins and ples from quartz veins clay seams occur in the with minor sulfides con quartz diorite. tained 3 and 50 ppm Cu, respectively. 55 Hugh Miller Zn West side of Thin iron-stained pyrite- None recorded. A select USGS sample tak- MacKevett, 1971, O Inlet mouth of Skid- bearing veins cutting en in 1966 of the best p. 55, location I to more Bay near quartz diorite suggested looking material in the no. 45j this cn junction with as possible fringe zone veins yielded 1,500 ppm investigation. O Hugh Miller of stockworks (low-grade Zn, 70 ppm Bi and a trace Inlet. Precise Cu-Mo) to west were samp of Mo (7 ppm). Chip samp locality was led in 1966, Thin iron- les in 1977 of a thin not found in stained veinlets and two iron-stained vein and two 1977. shear zones cutting quartz 2-ft. wide shear zones diorite were seen in 1977 j yielded no significant however the 1966 site was metal values. evidently not found. 56 Contact nuna- Au Pyrite and pyrrhotite None recorded. At the northern site, a MacKevett, 1971, tak occur as disseminations chip sample taken for 6.0 p. 79, location in limestone near a con ft. across an iron-stain no. 71j this in tact with biotite horn ed hornfels band in lime vestigation. blende granodiorite. The stone contained O.20 ppm hornfels occur as partings Au (AAS analysis), 5,000 or bands in the limestone. ppm As and 10 ppm Mo. A 2-0-ft. long chip sample taken across limestone with pyrite contained 0.10 ppm Au (AAS analysis), 10,000 ppm As and 20 ppm Mo. At the southern site, a 12-ft. spaced-chip sample taken across iron-stained Table C-46. Middle Geikie subprovihce occurrences not cited in text, continued. Mo. on Main Source of plate III commodity Location Description of deposit Mining claims Samples.*/ information Remarks 56 cont. hornfels.contained 5 pptn Mo. A sample collected between these two sites, a composite selection of iron-stained hornfela, limestone and granodiorite with pyrite and pyrrhotite contained 5 ppm Mo. 57 Fourth of Cu Bast side of Heavily red-brown stained None recorded. Two composite grab samples This inveati- One of two July Brady Glacier gossan as rubble and out*- of float and a third from gation. widely Mountain ' about 7 miles crdp in steep gully consis material in place contain separated, i"1 northwest of ting of several gossan 130-160 ppm Cu (*A> i nil to very conspi head of Geikie zones across an estimated 20 ppm Mo (spec) , and 0.5 cuous gossans. Inlet. North 75-ft. width. Length un to 2 ppm Ag (spec) . Petro- west peak of certain. Considerably graphic samples of gossan mountain at sericitized and chloriti- contain traces of chalco- 4,400 ft. ele cally altered dioritic pyrite. vation. host rocks. Minor ande- site. 58 Charpentier Mo East of the Flat-lying altered zone None recorded*. MacKevett (1971) reports MacKevett, 1971, Inlet head of Char about 50 ft. wide occurs that a spaced-chip sample p. 79, 82, loca pentier Inlet in fine-grained diorite. taken for 30 ft. across tion no. 47. at an eleva the most mineralized sec tion of 1,600 tion of the altered zone ft. contained a trace of gold (AAS analysis), 150 ppm Cu, 7 ppm Mo and 1% Ti. I/ All concentration values cited were obtained from seraiquantitative spectrographic analysis, unless otherwise noted. 9-1267 South Geikie sub-province The southern portion of the Geikie province consists of the area between Dundas Bay and Geikie Inlet and it is composed of Paleozoic limestone, volcanics and other sedimentary rocks intrude^ by Tertiary and Cretaceous granitics. Figure C-2 shows the area and the important 5 ! prospects in it. | The most important mineralization found to date in the area is the ! Threesome Mountain stockwork molybdenum-tungsten prospect. Although ; i not of economic size or grade the occurrence of stockwork-type molyb- j i denum-tungsten mineralization at the southern end of the Geikie pro- i 10 i vince series of granitics in a geologic setting, similar to that found ! i at the Margerie Glacier porphyry copper-tungsten deposit located 37 12 i miles to the northwest, encourages prospecting for additional porphyry j 13 deposits in the intervening granitic intrusives. j 14 Low-grade tungsten was found in contact rock by following up a 15 USGS stream-sediment sample taken in the head of the east arm of 16 ! Dundas Bay. Although this zone is fairly small, other granitic marble : contact zones in the area may contain more extensive contact-type 13 tungsten deposits. Numerous claims were located in the area between 1934 and 1947, 20 i mostly for gold, although our investigation did not reveal significant 21 gold mineralization. 23 24 25- G-252 Threesome Mountain molybdenum tungsten deposit The -Threesome ^Mountain molybdenum tungsten deposit is located on a ridge and cirque southeast of Threesome Mountain and was discovered and staked in 1968 by Alvenco Inc. with the Moly 1-24 claims. The mineraliza tion takes the form of quartz-molybdenite-scheelite fracture coatings or fillings in fractures capping a Tertiary granodiorite stock that intrudes Devonian volcanics, limestone and Cretaceous granitics. Figure G-56shows the sample locations and the approximate limit of molybdenite mineraliza tion as determined by brief examination. Figure G56near here The fractures strike N50°-80°E and dip at 25° to 76° West/and the quartz-molybdenite coatings averaged about 0.08-feet thick and never exceeded 0.2-feet thick. Analysis of these fracture coatings indicated greater than 2,000 ppm molybdenum, up to seven ppm silver, up to 330 ppm copper, and up to 4,917 ppm tungsten. Table 647gives the analytical results. The highest mineralized-bearing fracture density found was Table G47near here eight per hundred feet. In 1969 Alvenco Inc. put down three diamond drill holes to evaluate this prospect. The results of their investigation were not made available for this report, but they apparently were not encouraging and the claims are no longer active. C-253 136° 35 EXPLANATION Approximate limit of molybdenum stockwork as determined by 58° very limited exami - nation 32 .7SI66 Sample location o to en Assay data given in table C-47 Contour interval 100 ft. 0 1000 2000 Abyss ....I "1 T meters Lake 0 200 600 Base from U.S. Geological Survey 1 : 63,360 Mt. Fairweather C-2, 1973 Figure C-56 Threesome Mountain molybdenum-tungsten prospect, sample locations 00 g CD Cft oCft ex CO Q o P a 3o z. . r 8 W*0) -O o G) e r Samples taken of iron-stained hornfels in the stratigraphic section near the occurrence contain up to 200 ppm copper, 50 ppm tungsten, 0.7 ppm silver and five ppm molybdenum. Although this occurrence as it is currently known is not of economic size or grade, it and the intrusive rocks in the area and the intrusive- stratigraphic section contacts are of exploration interest. C-256 9-1267 Dundas Bay tungsten prospect i 2 ! Two stream sediment samples collected in 1966 from the head of i 3 I the east arm of Dundas Bay contained anomalous tungsten, tin and molyb- 4 denum. Additional stream sediment sampling in 1976 confirmed this 5 |geochemical anomaly and isolated the drainages contributing anomalous 6 ivalues in these elements. Five of the 15 stream sediment samples i 7 collected contained tungsten as powellite or scheelite. Figure C-57 Figure C-57 near here 10- shows the stream sediment sample locations and the tungsten, tin and molybdenum contents. Two samples that contained a trace and 150 ppm i tungsten, respectively, were collected from a drainage west of the head i of the bay. The watershed of this stream comprises a saddle at an i I elevation of 1,650 feet, a 2,325-foot peak and a tarn located south of ; i I i this peak. Traces of tungsten were detected in samples from the ; i i drainages of a 2,146-foot peak northeast of the saddle and from a lake ; i east of this peak. The remaining sample that contained a trace of tungsten was collected downstream from the junction of these drainages.' j ; Investigation was made of the saddle and the 2,325-foot peak, and i i | samples from these locations contained from 20 ppm to 79 ppm tungsten. i Figure C-58 shows the geology of this area and the sample locations, ' 22 Figure C-58 near here C-257 Base from U.S.Geol. Survey l : 63,360 Mt. Fairweather B-2,I97I EXPLANATION Contour interval 100ft. A 150,70 ,7 Stream sediment sample location 0 .25 .50 and analysis, showing tungsten, tin, t i i i i miles and molybdenum content, respectiv- I I T kilometers ly, in ppm (semiquantitative spec- 0 -25 .75 trographic analysis)______Figure C-57 Head of the east arm of Dundas Bay, stream sediment sample locations 0258 Base from U-S. Geological Survey, 1:63,360 Mt. Fairweather 8-2, 1971 EXPLANATION Tggd Hornblende-biotite granite (Tertiary) Kgfo Foliated hornblende diorite (Cretaceous) //////, Limestone ft skarn with interfingered altered diorite Contact, dashed where concealed, generalized from plate I £ Strike and dip of foliation * Strike of vertical bedding ±GR071 Spaced chip or grab sample location Assay data given in table C-48 1000 feet meters 0 300 600 Contour interval 100 feet Figure C-58 Dundas Bay tungsten prospect, sample locations C-259 9-1267 and assay data are given in table C-48. The foliated diorite is part Table C-48 near here a large body that extends over 16 miles from north to south, and about 5_ !four miles from the east to west at its widest point (Seitz, 1959; 5 j !Rossman, 1963). The moderately well developed fabric of the diorite ' i !j is the result of subparallel alignment of hornblende and plagioclase (crystals. Seitz (1959) believed that the diorite was derived from bedded 10 '5 16 C-260 51 2 3 0> CA N r » i ^3' (A O $ a a. a n«j ^^* O § O ± 3" IA r r r3"i r -4- 0 I! (A o> ^ " 5 ?' 5 J C\ ^" t S §' -si ^^l5 »1 ^e O 0 H CA 0 o 9-1267 sedimentary and volcanic rock. In some areas, inclusions occur within i the diorite and it is common for the long dimension of the inclusion to be aligned with the foliation of diorite. The inclusions are com posed of sedimentary and volcanic rock and, in some cases, of diorite more mafic than the enclosing foliated diorite. Alteration of the j I inclusions ranges from moderate metamorphism to nearly complete recrys- I tallization or metasomatism. The limestone inclusion exposed at the ', iI top of the 2,325-foot peak represents a relic bed which resisted | i chemical replacement and thus persists locally. Some of the limestone | 10 is altered to skarn and dike-like masses of altered diori'te cut' the ! inclusion. The skarn contains wollastonite, vesuvianite, grossularite, ] i epidote, diopside, tremolite, chlorite, biotite and powellite. The Tertiary granite that intrudes the Cretaceous diorite displays no preferred orientation of crystals and it is less altered than the diorite. Contacts of the granite with adjacent rocks are sharp and ! i contact metamorphism is slight. ! A composite grab sample taken in the saddle of quartz veins in diorite contain 20 ppm tungsten and a trace of gold. At an elevation of 1,900 feet northeast of the saddle, a composite sample of the diorite was collected and it contained 32 ppm tungsten and a trace of tin. Near the granite outcrop west of the saddle, float with molybdenite was : 22 found. At the top of the 2,325-foot peak a composite grab sample of , limestone and skarn contained 79 ppm tungsten, 8.5 ppm. gold -and 200 ppm bismuth. Another composite grab sample of skarn near the contact with the granite contained 150 ppm tin and a trace of silver. The contact ~~ C-262 " 1^1- ,;,-, ^T 9-1267 between the limestone and diorite is exposed in a north-trending gully leading from the peak. A 90-foot long spaced-chip sample collected across the contact zone contained 0.10 ppm gold. Trace amounts of molybdenum were detected in most of the samples. 10 12 13 15 16 17 22 23 C-263 Gold placer south of Wood Lake Gold placers have been reported south of Wood Lake in the Mt. Fair- weather C-2 quadrangle and also in the upper Dundas River drainage (Rossman, 1963b). Placer occurrences south of Wood Lake and within the C-2 quadrangle but not in the Dundas River drainage would have to be restricted to a drainage area of less than two square miles immediately south of and draining into Wood Lake ( plate III). A ground inspection was not made. Low level helicopter inspection revealed no evidence of cabins, cabin remains or of localities showing evidence of placer workings No placer claims are known to have been located in this vicinity. Placer claims have been located about five miles southeast of Wood Lake on an easterly fork of the Dundas River, however, and are discussed under the heading "Valley of Tears placer" in the South Chilkat province text. They are situated about 1.3 miles south of Lake Seclusion, locally known as Dundas Lake. Four miles due south of Wood Lake on the main Dundas River at a locality where in 1976 the river was against the west bank, a very wide- braided river bar was sampled. Twenty standard stream-sediment samples were taken at reasonably uniform intervals along a 1,600-foot line normal to the river. No gold was detected by atomic absorption methods in the minus 80 mesh fraction. (Limit of detection is reported by USGS to be 0.05 ppm). Other occurrences or prospects in South Geikie- subprovince The remainder of the prospects in South Geikie subprovince were not investigated in as much detail and may not be as significant as those C-264 discussed above. Their location is shown on plate III/ and table C-49 contains pertinent information on them. Table (249 near here C--265 Table C-49. South Geikie subprovdnce, occurrences npt discussed in text. No. on Name of Main Source of plate III prospect commodity Location Description of deposit Mining claims Samples / information Remarks 22 Brady Glacier (See remainder of Fairw eather pro v i n c e) outwash 59 Geikie Inlet Cr South of the Chromite with subordinate Eight claims staked A spaced-chip sample Juneau Recording Location chromite head of Geikie clinochlore with chromium for chromite in from a lamprophyre dike District claims uncertain. claims Inlet. occur on blebs in laropro- 1957; assessment in the vicinity con- records; Donald o phyre dikes in diorite work performed in tained 0.10 ppm gold McDonald, oral near a dunite body. 1976. (AAS analysis) , but communication, only a background con- 1977 . test of Ni and Cr. .._ . Mo South of Geikie Molybdenite reportedly Four olaims were MacKevett, 1971, Location 60 South of Gei- * . TT . . _ , . Inlet near occurs in tactite near staked on Black p. 70, location doubtful . kie Inlet near , ... Blackthorn , , ^. Blackthorn^ . . , Peak ."Wood Glacier.", . ' . which, thorn Peak in no. 50; Buddington at a high ele- has receded with Wood 1958. Assessment (1942) vation. Lake now occupying work was recorded Budding ton and states that part of the valley. in 1959. These Chapin, 1929, p. molybdenite claims were repor 329-330; Smith, ore was ob . tedly staked for 1942, p. 178} tained from Ni. this investiga near Geikie tion; Juneau Inlet in Recording 1918. Inves District claim tigations in records . the area in * 1966 and 1975 failed to reveal any sign of claim workings or the minerali zation reported . Table C-49 South Gcikie subprovince, occurrences not discussed in text,con 1 t. Main Source of commodity Location Description of deposit Mining claims information Remarks 61 West of Fe Seitz (1959) reports that None recorded, MacKevett, 1971, Location un Blackthorn a magnetic anomaly was p. 72, location certain. Peak discovered using an air no. 51i Seitz, plane compass near Black 1959, p. 115-116. thorn Peak. The aero- magnetic survey conducted O during the present inves tigation revealed a large magnetic anomaly centered about 6 miles northwest of Blackthorn Peak. The latter anomaly definitely should be investigated. 62 South of Mo None recorded. A rock sample collected This investiga Geikie in 1975 contained 700 tion. Inlet ppm Mo. molybdenum occurrence 63 East of Pe, Three and three- Skarn lenses up to 15 ft. None recorded. One 0.75-ft. long chip This investiga Brady Gla- Cu fourths mile thick at a granodiorite* sample of a iron-stained tion; MacKevett south of Abyss marble contact. The lens contained 1,400 ppm and others, Lake at an lenses contain magnetite, supper (AAS analysis), L 1971, p. 72, altitude of garnet, quartz, calsili- gold (AAS), 1.5 ppm location no. 54. 1,300 to cate minerals and some silver and 20%- iron. 1,700 ft. pyrite and chalcopyrite. Other samples ranged in Total field magnetometer length from 4.5 to 35 anomalies of up to 5,000 feet of skarn lenses in gammas were found at one the area and contained up lens. to 750 ppm copper (AAS), L gold (AAS), 0.7 ppm silver and greater than 30% iron. Table C-49. South Geikie eubprovince, occurrences not discussed in text, continued. No. on Name of Main y Source of >late III prospect commodity Location Description of deposit Mining claims Samples information Remarks 64 East of Au East of lower Gold-bearing quartz veins None recorded. A stream sediment sample MacKevett, 1971, No in place lower Brady Brady Glacier at occur in mafic gneiss and collected at an eleva p . 67 i Rossman , quartz veins Glacier an elevation of diorite. The veins arc- tion of about 25O ft. 1963a, p. K50. seen during appr. 450 ft. in only a few tenths of a contained 0.40 ppm Au this investiga a 1976 inves a stream cut. foot wide and are exposed and 230 ppm Cu (both tion. tigation. for only a short distance AAS analyses) . The The stream along strike. sample included frag cut was ments of quartz with filled with finely disseminated snow down to to pyrite and chalcopyrite. an elevationn o» MacKevett (1971) reports of about oo that a composite grab 375 ft. sample from quartz veins up to 0.8 ft. thick contained a trace of Au (AAS analysis) and 100 ppm Cu. 65 Lower Urady Mo - Float from molybdenite- None recorded. None. MacKevett, 1971, Location Glacier bearing quartz veins p. 79, location uncertain. reported. no. 56} Smith, 1942, p. 177; Budding ton and Chapin, 1929, p. 329- 330. * 66 West of Dun- Au, Lode gold occur 1.966: deposit not found. In 1930 "Doc" 1975: A channel of a MacKevett and According to das Bay ("Doc" Ag rence reported "Probably consists of Silver, with 1.9-ft. wide quartz vein others, 1971, Stewart Silver pros to be on north small gold-bearing several other containing 0.4 ft. p. 67, location (1949), in pect?, Red shore of the quartz veins in dioritic people, record- gouge zone yielded 250 no. 57; this 1933 "Doc" Top proper- peninsula bet rocks." 1975: One-1! ft. ed at least 47 ppm Pb (AA) , 5 ppm Ag investigation; Silver held ty?) ween Dundas thick quartz vein dipping lode claims: (spec), and 0.275 oz. Stewart, 1949, Red Top il Bay and its 65°W in altered hornblende the 24 Sunrise, gold/ton by fire assay. (PE-111-3)} and 12 claima west arm. diorite in west wall of 15 Newsboy, and Composite grab of nearby Charles Janda, He described Table C-49. South Goikie subprovince, occurrences not discussed in text, continued. No. on Name of Main . Source of plate III prospect commodity Location Description of deposit Mining claims Samples information Remarks 66, cont. steep gorge at about 45'o 8 Red Top claims, altered hornblende dio- oral communica a 1 to 2 ft. ft. elevation. No work Position of these rite gave no significant tion (1975), thick quartv, ings were seen. Old pipe claims was some- metal values. indicated that vein in the cable, and hose at vhere in this part "Doc" Silver west side of slightly lower elevation. of Dundas Bay. Red property was in a rocky Building ruins near Top property was this drainage. gorge in dark beach. examined by dioritic O Stewart (1949) in rocks at the I 440 ft. ele . to 1938. Location is cr> not clear. vation dip vo ping 65°W. This loca tion may be the same as that sampled by USBM in 1975, al though surface and under ground work ings reported by Stewart (1949) were not found in 1975. Work ings could easily have been nearby as this drainage is rugged and very brushy. Table C-49. South Geikie subprovince, occurrences not discusseti in text, continued. Main Source of commodity Location Description of deposit Mining claims Samples -* information Remarks 67 West arm of Cu, West side of Hornblendite dikes up to None reported. Analysis of a 1966 grab MacKevett and Dundas Bay Ag, very small is 10 ft. thick in gneissic sample of copper-bearing others, 1971, island Co land in south host contain dissemina hornblendite gave 10,000 p. 51, location western Dundas tions and small sulfide ppm Cu (spec) while 1975 no. 58; this Bay. lenses with visible grab samples of two small, investigation. O chalcopyrite (lenses up high-grade lenses in the to 2 inches x 6 inches). hornblendite yielded ->Jto Dike exposures are limit 18,000 ppm Cu (AA), 3 ppm O ed and contacts very ir Ag (spec) and 700 ppm Co regular. Length not (spec) each. determined but could not be great because of small size of island. 68 East side of Cu About 1/2 mile Highly fractured quartz None recorded. Continuous chip samples This investiga Dundas Bay northeast of stringer zone in quartz from 0.4 to 3.2 ft. long tion? MacKevett Triangulation diorite gneiss that is of the zone contained up and others, Station "Deed" about 5 ft. wide and to' 1,900 ppm copper (AAS 1971, p. 72, extends for about 40 ft. analysis), 10 ppm molyb location no. 54. between the high tide denum and I ppm silver. line and extensive These samples were taken cover. Some copper across the best minerali stain. zation in the 40 feet exposed. 69 East of Dundas Fe - Iron deposit shown on Four claims MacKevett (1971) reports MacKevett, 1971, Location Bay unpublished map by staked for iron that stream sediment p. 20, location uncertain, Rossman, probably in 1903 in the samples from the area no. 33) Juneau along contact between vicinity. Five contained anomalous THM Recording District quartz diorite and additional values. claim records. marble . claims staked in the area for unspecified com modity between 1891 and 1953. Table C-49, South Geikie aubprovince, occurrences not discussed in text, continued. No. on Main Source of plate III commodity Location Description of deposit Mining claims Samples I/ information Remarks 70 Fern Harbor West side of In 1933, three claim See description of 1,1-ft. long channel This investiga claims Fern Harbor. groups, the Tomboy, deposit. across two narrow tion. Melvina and Fern were quartz veins and a staked in the area. brecciated zone con This investigation tained 160 ppm copper revealed an old cabin (AAS analysis). and narrow quartz O carbonate veins in to greenstone exposed -JJ I-1 along the shoreline. I/ All sample values cited were obtained from semiquantitative spectrographic analysis, unless otherwise noted. Muir province Muir Inlet favorable area The Muir Inlet favorable area is about nine miles wide and extends from east of Muir Inlet to Queens Inlet and Gable Mountain, a dis tance of 22 miles. Plate III shows the location of the area and figure C-2 the important deposits in it. Prior to 1900 most of the area was covered with glacial ice. From 1900 to the present, Muir Glacier has made a spectacular 21-mile retreat closely followed by the prospectors who realized the mineral potential of the area as early as 1912. Claims with names such as Spring Maid and Bjorn were staked on the north side of the mouth of Adams Inlet almost in the shadow of the retreating glacier in that year. Molybdenum was first recognized in the area as early as 1918 when S. H. P. Vevelistad "7 staked the Molybdenum and Molybdun Quartz claims about two miles south of the Nunatak Molybdenum Deposit that was then almost wholly covered with glacial ice. In 1941 John Johnson and Tom Smith claimed the deposit now known as the Nunatak molybdenite with the O.K. nos. 1-4. In 1965 VanHorn Ridge was staked with the 63 Ursus claims for molybdenum and the south end of White Thunder Ridge was staked with the two iron claims. In 1968 the 56 Muir claims were staked on possible north and east extensions of Nunatak Molybdenum deposit and the Bruce 1-50 claims were located over the Bruce Hills. In 1968 the Dog 1-55 were located on Bruce Hills. The area is open with excellent rock exposures, has moderate relief and has been moderately well prospected. C-272 The area is characterized by Cretaceous and Tertiary dikes and plugs of porphyritic granitic composition intruding Silurian through Permian homfels, calcsilicate hornfels or schists and consists of east- west trends as opposed to northwest trends that are characteristic of the remainder of the monument. The most significant mineralization often takes the form of quartz stockworks, fracture coatings or dissemi nations in rock shattered by intrusives or along fault zones. Molybdenum and copper mineralization are found throughout the area. ! Two important deposits are located in the area: the Nunatak molybdenum stockwork deposit containing a large low-grade molybdenum resource and having excellent potential, and the Bruce Hills porphyry deposit containing low-grade resources and also having excellent potential. Numerous additional less important prospects are located in the area. C-273 The Nunatak molybdenum deposit Introduction The Nunatak molybdenum deposit is located on the east side of Muir Inlet around a 1,100-foot high isolated knob known as "The Nunatak." Figure G2 shows its location. It consists of stockworks of quartz-molyb- denV veins in skarn forming large low-grade molybdenum deposits with ^ current exploration potential as well as important future economic potential. In 1941 John Johnson and Tom Smith discovered this deposit and staked it with the O.K. nos. 1-4. During the summer of 1942 a party from the Geological Survey mapped the Nunatak deposit and a party from the Bureau of Mines systematically channel-sampled the deposit and drilled two diamond drill holes. This work was reported in 1946 (Twenhofel, 1946) and 1949 (Sanford and others, 1949). In 1964 James A. Walper'(the current claims owner) staked the deposit with the Nuna 1-30 and 34-38 lode claims (Moerlein, 1977). In 1966 the deposits were explored with three diamond drill holes by American Exploration and Mining Co. In 1966, the Geological Survey reexamined the deposit and their work consis ted of the following: checking Twenhofel's geologic map, collecting numerous chip and soil samples, and taking a few pertinent rock and C-274 mineral specimens (Mackevett and others, 1971, pp. 374-375). In 1968 \ Superior Oil Company drilled seven holes (totaling 5,430 feet), mapped the area on a scale of 1" = 250", collected rock geochemical samples, and did some geophysical work to determine the depth of the moraine to the east of the Nunatak. This deposit was briefly visited in 1975 and 1977 by the Bureau of Mines. The following description of the geology and ore deposits is modified mostly from written communication with George Moerlein who mapped and sampled the prospect in 1968 while working as a consultant for Superior Oil, and to a limited extent from earlier work on the deposit by MacKevett, Sanford and Twenhofel. Plate IV shows "Moerlein's" geology, important mineralized areas and drill hole locations. Geology The region is composed of limestone and limey argillites of probable Paleozoic age which have been intruded by quartz monzonite that is exposed as dikes and plugs on the Nunatak. These sediments strike in a northerly direction and dip steeply to the east and west. The sedimentary section shows a discontinuous "alteration" envelope where it is in proximity to the quartz monzonite. Outward from the quartz monzonite the limestone and limey argillites have progressively superimposed in them a silicified halo, a skarn halo, and lastly a cherty halo (see plate IV). Moerlein<1968a) believes these haloes are definitely related to the molybderitlm mineralization and are not separate sedimentary rock units as mapped by the Geological Survey (Twenhofel, 1946). C--275 - The silicified halo consists mostly of white bull quartz replacing both intrusive and skarn rocks, and contains only traces of molybdenum. The skarn alteration is of two types: epidote skarn and skarn containing zoisite and diopside with variable actinolite marginal to fractures and quartz veins. Molybdenum occurs in both skarn types, but the latter type with actinolite is the host for the important higher grade minerali zation exposed in drill holes near the stock. (These types are not differentiated on plate IV.) With the exception of the outcrops north of the Nunatak, skarn alteration is everywhere accompanied by quartz veining. Skarn alteration is believed to be the primary control of molybdenum mineralization with faulting and breccia zones exerting secondary control. Numerous post metallization dikes cut the sediments, "alteration" haloes and quartz monzonite porphyry. The rocks that have undergone cherty "alteration" contain micro-crystalline quartz with variable amounts of diopside and zoisite. At places this halo retains the original sedimentary features of the section it has invaded. The cherty "alteration" is the least intense ,of the three haloes and is barren in molybdenum mineralization. Molybdenum ore metal mineralization The molybdenum ore deposits consist mostly of closely-spaced quartz veins and veinlets containing selvages or thin films of molybdenite along their borders, rosettes of molybdenite crystals, and disseminations of molybdenite. Besides molybdenite and quartz, the veins contain minor to trace amounts of pyrite, pyrrhotite, chalcopyrite, tetrahedrite- bornite and euaugite. These veins usually strike N70^W to West, dip C-276 vertically, and are usually an inch or less in width, but are locally as much as several feet wide. In the area of skarn alteration the rocks are more highly mineralized than the surrounding rock, but out of the area of skarn alteration they are mostly unmineralized. The intrusive porphyry, the silicified rock, and the cherty rock appear to be unfavorable host rocks for the molyb denite mineralization. Stockwork-type quartz veining related to the alteration haloes outward from the porphyry is the primary control of ore deposition. Faulting and broad breccia zones are common in the area, and probably occurred contemporaneously with the period of mineralization and to some extent before and after, and exert a secondary control on mineralization. In general, the molybdenum mineralization surrounds the quartz monzonite porphyry dikes and plugs exposed on the Nunatak. It extends to the beach on the north side and to a small lake on the south, a horizontal distance of 4,600 feet over a vertical exposure-of 1,100 feet. The mineralization is open to the northwest where it extends under Muir Inlet and to the northeast where it extends under extensive glacial moraine. Twenhofel (1946, plate II) divided the deposit into two areas: that exposed to the northwest near the beach he called the area of conspicuous molybdenite and that exposed around the Nunatak he called the area of inconspicuous molybdenite. In addition, Moerlein recognized a third potentially important area exposed by diamond drilling and described below. The highest grade mineralization found thus far is exposed on the C-277 9-1257 surface along the "Nunatak" fault and below the surface by three drill | i holes (AMEX #2, Muir #1 and #2) and based on limited data it appears toj form a discontinuous halo around the silicified rock and the quartz 4 Imonzonite porphyry. Table C-50 gives the drill hole results. The 5 'Table C-50 near here 7 ;preferred host rock for this mineralization is a pale green skarn cut by 20 to 50 percent quartz veins and well-seamed with actinolite. Sec tions A and B, plate III, are cross sections of the mineralized zones showing drill hole data. One can infer from the available drilling information that this molybdenum-rich zone (greater than 0.1 percent imolybdenum) varies from 90 to 160 feet wide (as intersected by 45° 13 j Wholes), and averages between 0.110 to 0.122 percent molybdenum for 14 i ! these drill hole intercepts. Above and below these zones in the 15 i idrill holes, the molybdenum content drops off to less than 0.03 percent 16 ; jmolybdenum. The zones appear to be dipping steeply to the east. The j mineralization exposed by Muir #2 follows the down-dip surface expres- i 13 sion of the Nunatak fault brecciated zone. Surface samples taken of this 19 ' ! ! fault zone by the Bureau of Mines in 1942 indicate that for a strike 2£_ I ' i length of 1,200 feet and for an average sample width of 10.2 feet it 21 i assays 0.11 percent molybdenum, figure C-59, and table C-51. This ! mineralization as exposed by drill holes and surface exposure extends 23 ' I : Figure C-59 and table C-51 near here C-278 . 9-1267 for 1,800 feet along strike and is open to the north and at depth where there is some indication that the zone width increases as the mass of the quartz monzonite porphyry is approached. This higher 13 12 13 C-279 Table C-50 Assay data, The Nunatak molybdenum deposit, diamond drill hole samples [Samples from intervals not listed were not assayed; from Sanford and others, 1949 and from Moerlein.1977] Muir no. 1 Sample Sample Sample depth, ft. interval, Sample depth, ft. interval From To ft. Mo,% From To ft. Mo,% 20 32 12 0.044 830 840 10 0.151 41 50 9 .022 840 850 10 .109 50 60 10 .007 850 860 10 .062 60 70 10 .007 860 870 10 .111 70 80 10 .004 870 880 10 .233 80 90 10 .009 880 890 10 .127 90 100 10 .007 890 900 10 .102 100 no 10 .022 900 910 10 .093 110 120 10 .011 910 920 10 .089 170 180 10 .038 920 930 10 .109 180 190 10 .013 930 940 10 .044 190 200 10 .011 940 950 10 .122 200 210 10 .016 950 960 10 .074 210 220 10 .025 960 970 10 .036 220 230 10 .013 970 980 10 .070 230 240 10 .002 980 990 10 .031 240 250 10 .002 990 1000 10 .097 250 270 20 N 1000 1010 10 .028 270 280 10 .002 1010 1020 10 .043 520 530 10 .004 1020 1030 10 .016 530 540 10 .011 1030 1040 10 .013 540 580 40 N 1040 1050 10 .021 580 590 10 .007 1050 1060 10 .024 590 610 20 N 1060 1070 10 .038 610 620 10 .009 1070 1080 10 .024 750 760 10 .013 1080 1090 10 .016 760 770 10 .020 1090 1100 10 .014 770 780 10 .016 1100 1110 10 .081 780 790 10 .029 1110 1120 10 .023 790 800 10 .095 1120 1130 10 .040 800 810 10 .031 1130 1140 10 .069 810 820 10 .035 1140 1150 10 .016 820 830 10 .077 1150 1160 10 .016 Mu1r no. 2 Sample Sample Sample depth, ft interval Sample depth, ft. interval From To ft. Mo,% From To ft. Mo,% 225 235 10 0.033 530 540 10 0.193 235 245 10 .062 540 550 10 .069 245 255 10 .095 550 560 10 .188 255 265 10 .060 560 570 10 .169 265 275 10 .056 570 580 10 .120 305 315 10 .077 580 590 10 .182 315 325 10 .044 590 600 10 .039 325 335 10 .040 600 610 10 .113 335 345 10 .017 610 620 10 .111 460 470 10 .067 620 630 10 .161 470 480 10 .035 630 640 10 .073 480 490 10 .084 640 650 10 .020 490 500 10 .089 655 665 10 .035 500 510 10 .120 665 675 10 .049 510 520 10 .082 675 685 10 .020 520 530 10 .118 685 695 10 .017 Sample interval Composite sample ft. Mo,% 460 - 470 to 480 - 490 20 0.061 620 - 630 to 640 - 649 19 .085 C-280 Table C-50 Assay data, The Nunatak molybdenum deposit, diamond drill hole samples, cont. Muir no. 3 Sample Sample Sample depth, ft. interval, Sample depth, ft. interval, From To ft. Mo,2 From To ft. Mo,* 95 105 10 0.020 135 145 10 0.062 105 115 10 .026 145 155 10 .033 115 125 10 .035 162 172 10 .052 125 135 10 .064 172 182 10 .020 Muir no. 4 Sample Sample Sample depth, ft. interval Sample depth, ft. interval, From To ft. Mo,% From To ft. 135 145 10 0.007 195 205 10 .033 145 155 10 .106 205 215 10 .031 155 165 10 .025 215 225 10 .053 165 175 10 .013 225 235 10 .009 175 185 10 .047 235 245 10 .017 185 195 10 .031 Sample interval Composite sample ft. Au, oz/ton Ag, oz/ton Cu,% MoS2 ,£ 135 - 147 to 175 - 185 22 N 0.018 0.063 185 - 195 to 235 - 245 20 0.1 .006 .051 Muir no. 5 Mineralization noted in hole not sufficient to justify assaying samples. Muir no. 6 70 feet of rock were cored. The hole was stopped because the alternation suggested that is was well outside the mineralized zone. Muir no. 7 Between 333 feet, the base of the gravel, and 598 feet, the bottom of the hole, no significant sulfides were noted. AMEX no. 1 Sample Sample depth, ft. interval, -Mo,! -Cu.X- From To ft. Sludge Core Sludge Core 10 20 10 N N 0.340 0.226 20 30 10 N N .126 .252 30 40 10 .056 40 50 10 .126 50 60 10 .277 .270 60 70 10 .270 .207 70 80 10 .220 .176 80 90 10 .245 .422 90 100 10 .144 .170 100 110 10 .107 .340 110 120 10 .384 .107 120 130 10 .088 .081 130 140 10 .170 .170 140 150 10 .100 .081 150 160 10 .094 160 170 10 .050 170 180 10 .044 180 190 10 .144 C-281 Table C-50 Assay data, The Nunatak molybdenum deposit, diamond drill hole samples, cont. AMEX no. 1, cont. Sample Sample depth, ft. interval, no,* From To. ft. Sludge Core Sludge Core 190 200 10 _ _ .050 _ 200 210 10 _ _ .107 - 210 220 10 - - .075 - 220 230 10 - . .044 - 230 240 10 _ . .018 - 240 250 10 . 0.006 .050 .025 250 260 10 - . .018 - 260 270 10 _ - .056 - 270 280 10 _ .002 .069 - 290 300 10 _ .001 _ - 300 310 10 _ N - - 310 320 10 _ .002 - - 320 330 10 _ .001 _ .069 330 340 10 _ N . - 340 350 10 _ N . . 350 360 10 _ N - - 360 370 10 _ N . - 370 380 10 . .013 _ - 480 490 10 _ .001 . .018 503.4 512 8.6 - .002 - .088 Sample Core sample- Sample depth, ft. interval . Mo,*-- Cu ,%- - Au, Ag, From To ft. Sludge!/ Core Sludge!/ Core oz/ton oz/ton 530 540 10 _ _ .113 N N 540 550 10 . _ .037 N N 550 560 10 N _ .037 N 0.1 560 570 10 _ _ .113 tr N 570 580 10 - - .056 N N 580 590 10 . - .081 N .1 AMEX no. 2 Sample Sample depth, ft. interval - no, /a From To ft. Sludge Core Sludge Core 20 30 10 0.048 0.017 _ _ 30 40 10 .050 .014 _ - 40 50 10 .075 .086 - - 50 60 10 .020 .009 _ - 60 70 10 .023 .008 . 0.050 70 80 10 .005 .002 - - 80 90 10 .012 .011 _ - 90 100 10 .009 .012 - - 100 no 10 .011 .004 _ . 110 120 10 .012 .004 - - 120 130 10 .014 .011 - - 130 140 10 .011 .013 - . 140 150 10 .013 .014 - - 150 160 10 .008 - 0.025 - 160 170 10 .016 - - - 170 180 10 .011 - - - 180 190 10 .008 - - - 190 200 10 .009 .005 - - 200 210 10 .007 - - - 210 220 10 .008 - - - 220 230 10 .019 - - - 230 240 10 .013 - - - 240 250 10 .023 - - - 250 260 10 .019 - - - 260 270 10 .013 - - - 270 280 10 .014 - - - 280 290 10 .011 .009 - - !_/ Sludge sample too small for accuracy beyond 280 feet. -C-282 Table C-50 Assay data, The Nunatak molybdenum deposit, diamond drill hole samples, cont. AMEX no. 2, cont. Sample Sample depth, ft. Interval LU.fc From To ft. Sludge Core Sludge Core 290 300 10 0.008 0.007 0.037 0.069 300 310 10 .019 .024 _ 310 320 10 .011 .005 .516 320 330 10 .005 .001 «. 330 340 10 - .001 _ 340 350 10 .006 . _ 350 360 10 .016 .014 _ 360 370 10 .009 .013 _ 370 380 10 .013 .011 _ 380 390 10 .004 _ _ 390 400 10 .002 _ _ 400 410 10 .008 .004 _ 410 420 10 .011 .004 .044 .025 420 430 10 - .005 _ 430 440 10 .014 .004 _ 440 450 10 .023 . _ 450 460 10 .007 _ _ 460 470 10 .017 .011 .026 .037 470 480 10 .009 .007 _ 480 490 10 .013 _ _ _ 490 500 10 .014 I/ .044 _ 500 510 10 .019 7013 .012 510 520 10 .011 .009 _ 520 530 10 .013 .007 _ 530 540 10 .019 .019 _ 540 550 10 .021 .007 .019 550 560 10 .026 .013 _ 560 570 10 .023 .029 _ 570 580 10 .048 .077 .056 .056 580 590 10 .035 .036 _ 590 600 10 .053 .029 _ 600 610 10 .026 .021 _ 610 620 10 .040 .045 _ 620 630 10 .060 .037 _ 630 640 10 .057 .013 _ 640 650 ' 10 .186 .112 _ 650 660 10 .168 .053 «. 660 670 10 .588 .255 _ 670 680 10 .231 .053 _ 680 690 .10 - .033 _ 690 700 10 - .102 _ 700 710 10 .104 .080 _ 710 720 10 .162 .051 .012 720 730 10 .122 .029 _ 730 740 10 - .029 _ 740 750 10 - .062 _ 750 760 10 - .025 _ 760 770 -10 - .016 _ 770 780 10 - .002 _ 840 850 10 .020 .007 .025 _ 850 860 10 .007 _ «. 860 870 10 .038 N _ 870 880 10 .029 .011 _ 880 892.5 12.5 .035 .013 . I/Illegible entry in company drilling hole log. C-283 Table C-50 Assay data, The Nunatak molybdenum deposit, diamond drill hole samples, cont. AMEX no. 3 Sample Sample depth, ft, interval From To ft. Sludge Core 2 10 8 0.013 _ 10 20 10 .007 .009 20 30 10 .009 .016 30 40 10 .013 .004 40 50 10 .013 .007 50 60 10 .007 .011 60 70 10 .011 .004 70 80 10 .009 .002 80 90 10 .009 .007 90 100 10 .007 .009 100 110 10 .009 .007 110 120 10 .on .004 120 130 10 .017 .026 130 140 10 .016 .009 140 150 10 .007 .004 150 160 10 .007 - 153 160 7 _ .004 160 170 10 .007 .00417 170 180 10 .007 .004 180 190 10 .007 .011 190 200 10 .004 .002 200 210 10 ,011 .009 210 220 10 .009 .004 220 230 10 .009 - y 230 240 10 .002 240 250 10 .004 . 250 260 10 .004 _ 260 270 10 .031 .047 270 280 10 .029 .020 280 290 10 .036 .098 290 300 10 .033 .029 300 310 10 .042 .031 310 320 10 .038 .009 320 330 10 .016 .016 330 340 10 .004 .004 340 350 10 .007 .002 350 360 10 - .004 360 370 10 - .007 370 380 10 - .004 380 390 10 - .007 390 400 10 - .004 400 410 10 - .002 410 420 10 - .017 420 430 10 _ .009 430 440 10 - .004 440 450 10 - .009 450 460 10 - .020 460 470 10 - .004 470 480 10 - .017 480 490 10 - .002 490 500 10 - .004 U. S. Bureau of Mines drill holes ueyui, Hole ft. Core Sludge Adjusted average 1 46.7 0.043 0.041 0.042 2 238.1 .063 .073 .072 ]_/ Core sample also contained 0.037% Cu. 2/ Core recovery too poor from 220 to 260-foot depth for an accurate sample. c-284 X . . Channel Channel no. 31 Plan of the Channel no. Nunatak fault zone Contour interval 100 feet A A1 950'- Channel - 950' no. 20 Channel Channel Projected profile of the no. 21 no. 22 Channel hanging wall of the no 23 I i Channel Nunatak fault zone NJ| 850 - no.24 Channel - 850' 00 no. 25 Channel no.26 Channel no. 27 EXPLANATION Channel 75O - no. 28 - 750' Skarn with epidote and ____ sheared quartz Channel p|Qn of fau |} zone, showing channel Horizontal and Channel 650' sample location with conponent no. I vertical scale no.29 Channel h 650' on the east and no.2 on the west no. 30 0 100 200 Channel Profile of fault zone, showing I feet Channel no.20 .I/, / channel sample location I I meters io.3l 20 40 60 550 - - 550' Samples collected and assayed by the U.S.Bur.Mines for a 1942 investigation Assay data given in table C-51 450'- - 450' 420'- 420' Mod i fed from R S. Sanford and others, 1945, f ig. e Figure C-59 The Nunatak molybdenum deposit, Nunatak fault zone, sample locations Table C-51 Assay data, The Nunatak molybdenum deposit fault zone samples [From Sanford and others, 1949, flguri 6j Channel Length number Sample Ft. (fin.) Mo, % Description 20 4.5 < 1.4 0.06 Epldotlzed zone 1n skarn; east section of channel no. 20. O 20 3.6 1.1 .05 Sheared quartz zone In skarn; west section of channel no. 20. 21 6.0 i 1.8 .12 Epldotlzed zone 1n skarn; east section of channel no. 21. to CO 21 4.4 i 1.3 .04 Sheared quartz zone 1n skarn; west section of channel no. 21. 22 7.0 2.1) .10 Epldotlzed zone 1n skarn; east section of channel no. 22. 22 4.8 i 1.5) .09 Sheared quartz zone 1n skarn; west section of channel no. 22 23 6.0 i 1.8) .06 Epldotlzed zone In skarn. 24 5.8 i 1.8 .05 Sheared quartz and epidote 1n skarn; west section of channel no. 24. 24 5.7 1.7 .04 Sheared quartz and epidote 1n skarn; east section of channel no. 24. 25 15.8 (4.8 .04 Epldotlzed zone In skarn. 26 11.0 (3.4 .16 Do. 27 9.7 (3.0 .34 Do. 28 6.0 1.8 .24 Shattered quartz and epidote 1n skarn. 29 10.4 i 3.2 .10 Do. 30 11.2 3.4 .05 Do. 31 10.4 (3.2) .04 Weighted average value .10 grade zone together with the zone intersected by AMEX #2 and Muir #1 may prove with additional exploration to be the most important mineralization of the deposit. Identified'Resources The resources of the Nunatak molybdenum deposit have been estimated by Twenhofel (Twenhofel, 1946, p. 17) based on 1942 Bureau of Mines channel samples and U.S. Geological Survey mapping; by Sanford (Sanford and others, 1949) based on 1942 Bureau of Mines channel samples and drill holes; by MacKevett ("MacKevett and others, 1971) based on 1966 Geological Survey collected chip samples /the Survey considers their samples inadequate for satisfactory grade estimates (MacKevett and others, 197 \\Ji an<^ by Moerlein based on 1966 and 1968 diamond drill hole data (Moerlein, 1977, written communication.) For the purpose of resource calculations the Nunatak deposit has been divided into three areas: (1) stockwork with conspicuous molyb- ejaifie defined by the limit of 1942 Bureau of Mines channel samples; (2) stock-work with inconspicuous molybdenite defined by Twenhofel's 1942 and MacKevett 1 s 1966 mapping; (3) mineralized zones on the Nunatak exposed in the Muir #1 and #2 and AMEX #2 diamond drill holes and on the surface in the area of the Nunatak fault. Most of the mineralization in area #3 is included in the area #2 open pit calculation. All mineral resource calculations are based on an 11.5 cubic feet per-ton density factor. 1. Stockwork with conspicuous molybdenite: This area is delineated by the limits of the 1942 Bureau of Mines channel samples at the northwest end of the deposit and extends from sea level C-287 to an elevation of 360 feet over an 875-foot long by 600-foot wide area. Plate IV shows the area and drill hole locations and figure C-60 shows the Figure sample detail. In 1942 the Bureau of Mines cut 203 channel samples over a length of 1,440 feet and put down two diamond drill holes (maximum hole length 238 feet) in the area (USBM #1 and #2). Table C-52 gives the channel sample results. In 1966 the USGS collected numerous chip samples in the area and in 1968 Superior Oil (Moerlein) Table G52near here put down two diamond drill holes (maximum hole length 245 feet) and collec ted eight grid-type widely-spaced geochemical samples in the area. This area above sea level forms a triangular prism with a length of 875 feet, a width of 600 feet, and a height of 360 feet. This area contains 8.2 million indicated tons that are amenable to open pit mining. There are an additional 9.1 million inferred tons in the area located between sea level and 200 feet below sea level. The Bureau of Mines channel samples in the area have a weighted average grade of 0.06 percent molybdenum. The four drill holes in the area ranged in average value for the portions sampled from 0.039 to 0.072 percent molybdenum. Superior Oil's eight surface grid samples averaged 0.06 percent molybdenum and 0.02 percent copper. MacKevett estimates an C-288 hannel no. 2 o 30 so 90 Feet I y \'/ * ' 0 to ao so Meters Contour interval 10 ft. EXPLANATION Glacial moraine Channel no. 10 Hornfels Limit of area of conspicuous molybdenite Channel noJ^A Location of channel f\ sample, sample interval fiv« feet for channels nos. I through 8 Samples collected and assayed by the US.8ur.Mines for a 1942 investigation Assay data given in table C-52 Modified from Saodferd and athtrt, 1949, figurt 4 Figure C-60 The Nunatak molybdenum deposit, area of conspicuous molybdenite, sample locations Table C-52 Assay data, The Nunatak molybdenum deposit, area of conspicuous molybdenite [From San ford and others, 1949, figure 5] USBM Channel Samples -v*iiaimci HU. i Channel no. 2 SampleV Mo.X Sample Mo,%~ Sample Mo.S Sample MO,, Sample Mo,% 1 0 .09 11 0. 10 21 0.07 31 0.07 1 0.03 2 .07 12 . 14 22 .06 32 .05 2 .05 3 .09 13 ^ 08 23 .06 33 .09 3 .03 4 .09 14 ^ 12 24 .05 34 .06 4 .07 5 .04 15 B 04 25 .05 35 .07 5 .02 6 .04 16 B 05 26 .04 36 .08 6 .04 7 .08 17 m 07 27 .05 37 .10 7 .05 8 .08 18 . 05 28 .06 38 .04 8 .03 9 .09 19 , 05 29 .09 39 .05 9 .06 10 .08 20 09 30 .05 40 .06 Channel no. 3 Sample Mo,% Sample Mo,!5 Sample Mo,% Sample Mo.X Sample Mo,% Sample Mo .1 1 0 .05 11 0. 03 21 0.02 31 0.03 41 0.02 51 0. 06 2 .07 12 . 08 22 .03 32 .04 42 .07 52 05 3 .03 13 . 06 23 .03 33 .13 43 .03 53 05 4 .04 14 . 06 24 .03 34 .03 44 .06 54 06 5 .08 15 ^ 10 25 .03 35 .06 45 .08 55 04 6 .06 16 . 05 26 .02 36 .07 46 .04 56 06 7 .08 17 . 04 27 .05 37 .04 47 .04 57 08 8 .09 18 ^ 02 28 .03 38 .08 48 .02 58 05 9 .10 19 . 03 29 .03 39 .04 49 .06 59 06 10 .10 20 04 30 .02 40 .04 50 .04 60 07 Channel no. 4 Channel no. 5 Sampl e Mo.X Sampl e Mo.X Sample Mo,!5 Sample Mo.X Sample Mo,% 1 0 .08 11 0. 06 21 0.06 31 0.06 1 0.05 2 .08 12 07 22 .10 ,2 .03 3 .07 13 a 14 23 .05 3 .08 4 .03 14 ^ 15 24 .08 4 .05 5 .06 15 . . 05 25 .05 5 .04 6 .07 16 . 13 26 .06 6 .05 7 .09 17 9 08 27 .04 7 .52 8 .09 18 , 09 .28 .05 8 .06 9 .12 19 , 07 29 .02 9 .11 10 .09 20 07 30 .06 -Channel no. 6 Channel no. 7 Channel no.«.* o--o Channel no. 9 ------Sample Mo,% Sample Mo ,% Sample Sample Mo,% Sample Mo,% 1 0.05 1 0. 02 1 0.05 1 0.05 6 0.11 2 .04 2 t 04 2 .04 2 .05 7 .08 3' .04 3 .06 8 .11 4 .07 4 .09 9 .08 5 .08 10 .07 Average for each Channel no. 10- channel sample Sample Mo,% Sample Mo ,x Sample Mo, % Sample Mo,% Channel Mo,% 1 0.06 11 0. 04 21 0.05 31 0.09 1 0.07 2 .10 12 06 22 .10 32 .21 2 .05 3 .05 13 04 23 .08 33 .09 3 .05 4 .05 14 05 24 .07 34 .11 4 .07 5 .07 15 04 25 .11 35 .10 5 .11 6 .09 16 04 26 .10 36 .07 62/ .05 7 .06 17 07 27 .09 727 .03 8 .04 18 05 28 .08 83/ .04 9 .03 19 07 29 .13 9 .07 10 .04 20 07 30 .20 in .07 Weighted average over all channel samples .06 I/Component1 rs* sample sections are 5 ft. in length (1.5 meters) for all channel samples. 2_/Includes 2 samples that are not representative. 3/Includes 4 samples that are not representative. C-290 average grade for the area of 0.04 percent molybdenum and 0.018 percent copper. Table C-50 and table C-52 give the drill hole and sample results. (Superior Oil's grid geochemical sampling results are available upon request from the AFOC field office in Juneau, Alaska.) 2. Stockwork with inconspicuous molybdenite: This area ranges from an elevation of 300 to 1,150 feet, is up to 1,100- feet wide, and 3,200-feet long. It is defined by Twenhofel's 1942 mapping that was later confirmed by 1966 U.S. Geological Survey geochemi cal sampling and mapping. Moerlein's 1968 geochemical grid sampling indicates a somewhat smaller sized area, with the location shifted to the east. In addition to the above geochemical sampling, MacKevett sampled the area in 1966 and there are five diamond drill holes located in this area that reach vertical depths up to 800 feet below sea level. Plave IV shows the area and sections A and B are cross-sections through the area showing diamond drill holes and mineralized zone intercepts. The recoverable tonnage calculations for this area are based on an approximately north-south running open pit with 60 degree walls and a floor depth 200 feet below sea level. On the basis of five approximately east-west sections there are 137 million tons of indicated molybdenum- bearing rock and 52 million tons of waste. Of this, 20 million tons of ore and four million tons of waste are located below sea level. Twenhofel estimated an average grade of 0.048 percent molybdenum for this area while Moerlein's 29 widely-spaced grid geochemical samples indicate an average grade of 0.07 percent molybdenum and 0.04 percent copper. Based on chip samples MacKevett (1966) estimates an average ' C-291 grade of 0.016 percent molybdenum and 0.18 percent copper. Molybdenum values from the five drill holes in the area are difficult to assess because of variations in core recovery and variations in the selection of portions of the holes for analysis. According to reports, two of the holes, AMEX #1 and Muir #5, contained insufficient molybdenum mineralization for analysis. Only portions of the other three were analyzed and these portions contained the following: AMEX #2 - 810 feet averaged 0.024 percent molybdenum; Muir #1 - 1,130 feet averaged 0.030 percent molybdenum; and Muir #2 - 320 feet averaged 0.084 percent molybdenum. Table CSOgives the diamond drill hole analytical results. 3. Mineralized zones on the Nunatak exposed in the Muir #1 and #2 and AMEX #2 diamond drill holes and on the surface in the area of the Nunatak fault: On the west side of the Nunatak, AMEX #2 and Muir #1 diamond drill holes intercept a mineralized zone with a minimum true thickness of 50 feet, plate IV, sections A and B. On the east, Muir #2 intercepts a mineral ized zone probably 160 feet thick that may have a partial surface expres sion along the Nunatak fault. Analysis of these drill hole intervals show grades from 0.110 to 0.143 percent molybdenum. The Nunatak fault zone on the surface has an average grade of 0.11 percent molybdenum for an average width of 10.2 feet. Indications are that this mineralized halo and fault zone may constitute an important higher grade portion of the deposit, but its character is not well enough known to accurately establish grade or tonnage. The mineralized tonnage in this area is mostly included C-292 in the open pit calculations described in area #2 above. Underground mining would be required to mine this halo by itself. Identified resources summary In the previous section all the various grade estimates have been listed for each area of the deposit. Tablets3 summarizes each area and reports what in the judgment of the present author, is the most representa tive grade. In summary, this deposit contains 145 million indicated tons Table O53 near here accessible to surface mining at a grade of from 0.04-0.06 percent molyb denum and 0.02 percent copper, and an additional 9.1 inferred million tons below sea level near the coastline at 0.06 percent molybdenum and 0.02 percent copper. Within the volume accessible to open pit mining is a potentially important higher grade section that, if taken by itself, would have to be mined from underground. The indicated gross in place value of the deposit as it is now known is $550 million. Mineralization outside the molybdenum area Moerlein's geochemical sampling indicates several small areas of copper mineralization mostly to the west of the area of molybdenum mineralization (results of Moerlein's grid geochemical sampling are available upon request from the] AFOC field office in Juneau, Alaska). A Copper occurs as chalcopyrite in disseminated specks and in shear zones cutting epidote skarn. The richest occurrence is in brecciated rocks due west of Muir #5 at the 100-foot contour. Here a 15-foot long chip C-293 Table C-53. Summary information on the resources of the Nunatak molybdenum deposit. Estimated* avg. grade Area Dimensions Tonnage percent #1 Stockwork with 875-feet long by 8.2 million indi 0.06% Mo conspicuous molyb- 600-feet wide, cated tons above 0.02% Cu denite zero to 360 feet sea level, an above sea level. additional 9.1 Additional area million inferred from sea level to tons below sea to 200 feet below level. sea level. #2 Stockwork with Mineralized zone 137 million indi 0.04% Mo inconspicuous up 1,100-feet wide cated tons of min 0.02% Cu molybdenite and 300-feet long. eralized rock, 52 Open pit designed million tons of around above area waste from open pit. with 60° walls, up Of the above,20 mil to 1,700-feet wide lion tons of miner and with a floor alized rock and 4 200 feet below sea million tons of level. waste are located below sea level. #3 Higher grade Exposed by drill Tonnage included 0.11-0.143% mineralized halo holes up to 500 in #2 area. Mo exposed in the feet apart. Esti- AMEX #2, Muir #1 mated width from and #2 drill holes 50 to 160 feet. and along the May be discontinu Nunatak &ult on ous halo around the the surface. stock. *An estimate of the average grade of the indicated area based on the extent and type of sampling, and on the various previous estimates. C-294 sample across a zone less than 100 feet in length assayed 0.554 percent copper; however, Moerlein estimates that these small zones will average in the 0.1 to 0.2 percent copper range. Rossman (1963b, p. k41) reports that a grab sample of quartz-rich rock that was collected from a gulley on the northeast side of "The Nunatak" contained 0.04 ounces per ton gold and 7.07 ounces silver per ton. Resource potential Twenhofel (1946, p. 18) indicates that at depth the quartz-monzonite stock probably increases in size and that the mineralized zone around it may correspondingly increase in size. This deposit is open at depth, to the northwest under Muir Inlet, and to the northeast under glacial moraine. The little known higher-grade mineralized halo exposed by diamond drill holes may prove to be the most important mineralization in the deposit. The deposit as a whole and this area in particular forms an excellent exploration target. Bruce Hills copper-molybdenum prospect Copper and molybdenum minerals occur in shear zones, disseminations, joints, and thin quartz veins in granodiorite and quartz diorite in at least two localities in the central part of the Bruce Hills between Burroughs Glacier and Wachusett Inlet (figureC-61) . The presence of Figure 661 near here copper and molybdenum in the Bruce Hills was first reported by Rossman (1963). C-295 I36°25' 136° 20' I36°I5' EXPLANATION Glacial ice and permo nent snowfields Biotite-hornblende granite and tonalite 59° (Cretaceous) 00' Biottte-quartz-feldspar hornfels, schist, sem! - schist, slate, and phyl- lite (Permian) o I 7K099X, Ni Contact, dashed where CTi -., f7^ >< ,,.p Figure" Q- concealed, generalized s . f f Fault, dashed where inferred Location of large D scale figure, outline not to scale A Sample location Base from U.S. Geol. Survey 1: 63,360 Mt. Fairweather D'l, D'2 1972, Assay data given in table C-54 Skogway A~4, 1972 .5 | | mile 0 .5 I i!s k ''ometers Contour interval 100 ft. Figure C-61 Bruce Hills location map Six claims were located in 1967 and 50 more in 1968 covering the above showing on the south slope of the central Bruce Hills and a second mineralized area on the north slope. The whole area including these mineralized showings was relocated with 55 claims in 1969. Claims are now inactive. During the present study reconnaissance was made in the central Bruce Hills and some detailed sampling was performed on both the south and the north slopes. The south slope area discussed by MacKevett and others (1971) consists of thin sulfide fracture coatings in a heavily iron-stained granodiorite that is shattered and brecciated in the vicinity of a prominent north easterly trending fault zone. Small roof pendants of hornfels and ande- site dikes are also present. U.S. Geological Survey geologists took 44 samples from a 4-acre area and analyzed each sample for total heavy metals (THM) in the field. THM, combined copper, lead and- zinc ranged from 20 to 600 ppm. Twenty- four of these samples were also analyzed by semi-quantitative spectro- graphic analysis yielding copper ranging from 26 to 710 ppm and molyb denum from nil to 90 ppm. Lead and zinc values were nil indicating that THM values are entirely due to copper. Much of the area was inaccessible because of steepness of the terrain or was covered with rubble or snow. They took eight additional samples from the area near the top of the fault gully obtaining copper and molybdenum values up to 3000 ppm and 1,000 ppm respectively from selected sulfide-bearing float, and 3^000 ppm copper and 70 ppm molybdenum in a spaced-chip sample across a six-foot C-297 wide altered zone. During the present examination the Bureau took spaced-chip and channel samples along a 150-foot line crossing the top of this fault gully where some of the best looking mineralization appeared. Figure C-62 shows sample localities while tableC54 gives sample assays and descrip tions. Assay returns ranged up to 610 ppm copper and 150 ppm molybdenum Figure C62 and table C54 near here across the larger chip sample lines, and higher values for shorter sample intervals across small iron-stained zones. A figure of 500 ppm copper and 75 ppm molybdenum is probably indicative of the average grade of mineralized material in this immediate area. A channel sample of a narrower joint filling contained more than 2£)00 ppm molybdenum. The best mineralization found is associated with joints, fractures and « veining; however, the host rock also is locally decidedly anomalous in both copper and molybdenum. The mineralized locality on the north side of the Bruce Hills was reported to the Bureau by George A. Moerlein based on work done there in the late 1960's (Moerlein, written communcation, 1971 ). He discussed a mineralized area about 400 feet in diameter containing an average of about 0.2 percent copper and 0.017 percent molybdenum. During the present study a mineralized area was examined on the north side of Bruce Hills, probably that described by Moerlein. Host rocks of iron-stained, fractured quartz diorite contain disseminations and veinlets of chalcopyrite and molybdenite. Some pyrite is also present. 'C-298 5K097 10 20 J_ I FEET ' METERS Mostly covered. Pro bably includes a diKe. EXPLANATION Granodiorite, iron-stained in 5K092 sections, containing goethite- coatea joints ana snear fractures (Cretaceous) StriKe and dip of joint or 70 shear fracture StriKe of vertical joint or shear fracture 5K086 O< Location of spaced chip \\ sample, one foot intervc 5K096\V length to scale K087 xx5K094 Channel sample location Assay data given in table C-54 Mopped by A. Kimbail and A. Clough, August 1975 Rgure C-62 Central Bruce Hills, south side, sample line crossing top of southwest trending fault gully C-299 -\ ooe-D ^ - ^s s\ e\ ^ °t j*p s $ 5 $ <; -? S ^ ^ ^ ^ § ^ "23. ^ ^ ^ ^ -0 >& ^ DO £ b § k k- \ \ s Ic^o& \ i M k$m ^ 0 ts\ & i cs ^ ^ ^ ^ H 0 0 a 0 O XJ 1 & £> ^ fty ^ ^ rn -n ;o o o, ro 0 ^ (M ,Ni 3> i § ^ ^ ^ 04 t»\ CO 1 i ^ ^\ .is - r~ i '^ :s4 wvs>t . § ^^ XJ s i^K ft. fc m !oo o -0 f\) O -4 D ? ifn rq| CM CM Oo Go JO WW > Oo ^ U) ?!'; O -J o O Q bfo g- 88 i^ r~» .^x i<^"'^^;8 * w t 0 X =l 4_ ; _4_ i_!_j_ -fe^^opp 5 i -'\r ?;z.2.fc!z. %v < -> l i ! i i 1 |F-)PL f ;o^ ^ I r-A A^ j** P"a. r! <*s \A* :^19 fe if i M -S -^ ?. £'l r? CK |T !^ K - ^ 3 .* .K i o i£ . tz i? ' ;i I'id * !.A i I 5 V ! ; Li : pIV ^ i I I.i UI._..... J! C-302 n o ro l U Eight-hundred feet of quantitative sampling comprising chips taken on one-foot intervals along seven sample lines in increments of three to twelve feet substantially covered available outcrops in a 350- to 400-foot diameter area on the steep-gullied hillside (figureC63 ). Table C54 previously cited gives copper, molybdenum and silver assay results. Copper ranged up to 3400 ppm for a 10-foot sample length while Figure C-63 near here molybdenite ranged up to 700 ppm, and silver nil to three ppm. Tonnage and grade calculations for this area have not been made; however, line no. 1, the most easterly comprising 22 samples from five to 12 feet in length and averaging nine feet in length taken in a steep gully with a slope line length of 325 feet have copper values ranging from 290 to 3,400 ppm and molybdenum values of from 12 to 700 ppm, giving numerical average values of 1,675 ppm copper and 260 ppm molybdenum (0.17 percent copper and .026 percent molybdenum). Assay values in this line were generally higher than those in the other lines so the average values of copper and molybdenum for the whole area are somewhat lower than the above figures. The area sampled (figure C-63) ranged in elevation from about 1,700 to 1,950 feet over a slope distance of about 400 feet. The uphill minerali zation limit toward the south was established by sample lines crossing it. C-304 1750 0 10 30 50 Lin« 6 I II . i I FEET I I I I METERS 0 5 10 15 Contour interval 50 fe«t. Mapped by A.Kimbail, J. Still, M.Parhe and M.Affl«cx , August 1977 EXPLANATION Dominantly iron-stained and fractured quartz diorite (Cretaceous) El. i9 Off. Spot elevation determined by anneroid altimeter Spaced chip sample location, length to scale Assay data given in table C-54 Rgure C-63 Central Bruce Hills,north side copper-molybdenum showing, sample locations C-305 The downhill, northerly limit occurs somewhere well before the southern margin of Burroughs Glacier is approached, probably between the eleva tions of 1,600 and 1,700 feet above a prominent west-trending fault. East and west, limits of the occurrence were less well established. Although sample values in copper and molybdenum appeared to decrease generally to the westward, iron-staining of rocks in gullies farther west indicate that the deposit may continue in that direction. The present sampling campaign was cut short by time and bad weather and did not extend into that area. Staining dropped off rapidly to the east of the easternmost gully sampled. Petrographic examination shows that the rocks from the 1,550- to 1,600-foot elevation contain no sulfides but are enriched in potassium feldspar as porphyroblasts and as fine veinlets cutting other minerals. The rocks are K-spar rich, fairly soft, and the ferromagnesium minerals have been partially altered to chlorite. In addition, the rocks downhill from this are shown through quantitative sampling to be practically barren of copper and molybdenum. Late potassium feldspar introduction is widespread and occurs south of the southside mineralized zone as well as a mile to the east, and at other localities not shown on the small scale figure. The importance of this area lies not in the occurrences which have been found as they are presently known, but rather lies in the area's potential for hosting large copper-molybdenum deposits. The widespread stockwork of K-spar veinlets cutting other rocks in the area, the chlorite alteration, the fracturing of the rocks, the wide area over which at least small amounts of copper and molybdenum are C-306 found, and the general nature of the host rock and extensive faulting suggest a favorable environment. Wachusett Inlet copper-molybdenum - - prospect This copper-molybdenum, occurrence is located on the very recently deglaciated north side of Wachusett Inlet at the high tide line and was investigated by the Bureau of Mines in 1975. This occurrence is the same as location number 35, plate I, in USGS Professional Paper 632 where it is incorrectly located. Figure C-2 shows the correct location. This occurrence consists of a quartz vein 50 feet long and up to 0.7-foot thick penetrating granitic rock and containing chalcopyrite, pyrite and molybdenite. The best sample came from the widest portion of the vein, 0.7 foot, and contained 7.4 percent copper and 0.02 percent molybdenite; other samples contained up to 0.15 percent molybdenite. Figure C-64 is a map of the vein showing sample locations and table C-55 gives the analytical results. This vein contained 800 inferred tons with an Figure C-64and table C-55 near here average sample assay of 0.44 percent copper, 0.005 percent molybdenum and 0.034 ounces per ton silver over a 4-foot mining width. Although not of economic size or grade over a 4-foot mining width this occurrence, because of its mineral concentrations and nearness to other significant C-307 approximate of shoreline tide Copptr- moiybdtn prospect location Bast fromU.S.Gtotoqical Survty 1:63,360 Mt. Foirwtothtr 0-2 1972 Location Map Contour interval 500 ft. ! milts kilomtttrs Broken granite, iron-stained in sections A5S203 Channel sample location or \5S207 Assay data given in table C-55 Mopptd by J.Still ond J.Rotoj, August 1975 Figure C-64 Wachusett Inlet copper-molybdenum prospect, sample locations C-308 Table C-S& Assay data^uy«cUu5 £"S2o/ CUa m*/ 1 a v ./2- 1? Ou*+-iZ. l/«/1 M M T I ^ 5"S?oi. 0.3 .09 ^,000 1500 1 Cl^^^z. S<«f£ie u^V. a>/f^ cbnlso/m+Sfe. 5~seo3 0,0!T .02. I^/YY) I5CO 5"7 5-SEo*/- ^ C>. V ,/a- ^/m i^roo SSZoS" a? .z; Xooo zoo 30 rSZot. .06 3= o 0.2 3t,COO 3CO 15 I CO ( y.' ' . deposits, encourages further exploration for larger occurrences in this very recently deglaciated area. Idaho Ridge prospect Examination was made at the area near USGS rock geochemical sample 75CN108A located on Idaho Ridge that contained 700 ppm molybdenum, 300 ppm tungsten and 10 ppm silver. The area consists of granitic rock with occasional fractures (some containing epidote alteration) and unmineralized brecciated zones. Samples were taken across the brecciated zones, across small fractures filled with quartz and sulfides, and across granitic rock adjacent to the fractures. The sample locations are shown in figure C-65 and the assay results are shown in table C-56. Two samples of the filled Figure G65and table G56near here fractures, 0.14 and--_.... 0.15 foot thick, contained 500 ppm tungsten, 300 ppm molybdenum, five to 15 ppm silver, and 100 to 240 ppm copper. Except for traces of molybdenum the remaining samples did not contain significant mineralization. These fractures containing quartz and sulfides are too widely spaced to constitute more than an interesting occurrence; however, detailed prospecting around the margins of this granitic intru sive might reveal more interesting molybdenum or tungsten mineralization. Minnesota Ridge prospect Minnesota Ridge is located on the west side of Muir Inlet north of Bruce Hills. The northwest portion of the ridge consists of occasionally iron-stained quartz diorite cut by a few andesite dikes. In 1966 the C-310 Base from U.S. Geol. Survey, I 63, 360 Mount Fair weather 0- I , 1972 EXPLANATION Glacial ice and permanent snowfields Biotite-hornblende granite and tonalite (Cretaceous) X 7S08I Sample location Assay data given in table .C- 56 Figure C-65 Idaho Ridge prospect, sample locations C-311 Table £-5~6 Assay data^I^K* Rt'^c. pros^c-f- Analysis PARIS PER ntLLioK Sample Length ^pr-c, srF,c» fcA SP»:-c Sample .Type Feet (m) W Mo Cu A«% Description J -7SO-7L 5"00 £U**!p 5". 3 Lk is! L. f\) TV o-"^ 1 1- A J^ , w .. » . j USGS found some low-grade copper mineralization in an outcrop surrounded I i | by snow fields. In 1976 the northwest portion of this ridge was investi- i ! gated from an elevation of 2,900 feet to Glacier Pass and it was found i that the 1966 snow fields were absent. Nine samples, ranging from grab 4 ! ; ! I j to 150-foot long spaced-chip, failed to reveal any significant minerali;- i zation, Figure C-66 shows the sample locations and table C-57 gives the analytical results. However, measured samples contained up to 190 ; Figure C-66 and table C-57 near here '0 ' \ ppm copper, 0.7 ppm silver, 0.10 ppm gold and 30 ppm molybdenum, and i 11 i s one selected grab sample of iron-stained quartz diorite containing i ,o ! i j small amounts of chalcopyrite smeared along tiny fractures assayed 490 j i i i ppm copper and 10-30 ppm molybdenum. j i Other prospects or mineralized areas ! ! ""~ Plate III shows the location of the remainder of the occurrences in the Muir Inlet -favora.V>\e~ a»-ea ~ ------an pertinent information on them. The most important of these is the i Gable Mountain occurrence (75) that contains copper, silver, molyb denum and tungsten mineralization along joint coatings. The remainder of the occurrences, although of low-grade and limited extent, indicate pervasive molybdenum or copper mineralization throughout the area. Table C-58 near here C-313 I36°I5' 59*00' Base from U.S. Geological Survey I-.63,360 Skagway A-4 EXPLANATION Glacial ice and Hornblende - biotite quartz permanent snow fields diorite (Cretaceous) A 6SI4I Sample location Assay data given in table C-57 Contour interval 100 feet 1000 2000 feet meters 0 200 400600 Figure C-66 Minnesota Ridge prospect, sample locations C-314 'cf>to D i C & \o J O Q O aUJ a T* srt oZ \o V) £ crrr 9 o- ) o VS cs o to CO -oO o en (/> o 3'\J No. on Name of Main Source of . plate IV prospect Commodity location Description of deposit Mining Claims Samples I/ information Remarks 71 Van Horn Mo ' Southwest Weakly mineralized iron- Sixty-three A composite grab sample MacKevett, . Ridge . end of stained altered zonet. claims were of iron-stained shale 1971, p. 74} Van Horn occur in hornfels and staked on the contained 150 ppm Cu location no. Ridge. shale and in granodiorite. ridge in 1965. (AAS analysis) and 15 11, Most of the zones are a- ppm Mo. MacKevett (1971) this investi long faults and are a few reports that a select gation, feet wide, not persisting grab sample from an iron- Juneau along strike. A few stained shear zone con Recording shallow pits and trenches tained 100 ppm Cu and 200 District explore some of the zones. ppm Mo. Three other claims samples from iron-stained records Q 1 altered zones contained u> from 20 to 70 ppm Cu and I-1 (7v from N to 5 ppm Mo. 72 Rfid Zn Three miles Pyrite-rich pods and Mono recorded MacKevett (1971) reports MecKevett/ "Deposit Mountain southwest of impregnations occur in * that a select grab sample 1971, p. 40, consid Red Moun limestone near a con from a sulfide-rich pod 53, 55, ered to tain at an tact with a granodiorite contained 1.5 ppm Ag, 70 location no. be too elevation of cupola. The largest ]>od ppm Cd, 30 ppm Mo/ 100 ppm 20. small .to 1000 fcot. is approx. 10 ft. lorn, Ni, 500 ppm Pb and 7,000 be of and 1 ft. in diameter. ppm Zn. economic significance." KacKfavett/197i p. .55 73 Curtis Cu North of Iron-stained zone 1-2 ft. None recorded A channel sample taken a- MacKevett, "Al Hills Wachusutt widu occurs contiguous to cross a 0.3 ft. wide 1971/ p. 44, though Inlet, mafic dikes that .cut l.orn- quartz-calcite vein con 73, 79, 62, the area approx. fels. These altered rones tained 300 ppm Pb (AAS location no. is almost 2S mi. contain quartz and qui rtz- analysis) and 15 ppm Ag. 23. virgin be west of calcite veins up to 05 ft. Assay of a select grab cause of Curtia wide. sample from a 4 ft. wide its recent Hills. iron-stained lens gave 150 denuda- Table C-58. Kuir province, Muir Inlet favoraole area, occurrences not discussed in text, cont. No. on Main Source of plate IV Commodity Location Description of deposit Mining Claims information Remarks 73, cont. ppm Cu (AAS analysis), 1% dation, Ti and a trace of silver. the de Two spaced chip samples, 3 posits in ft. and 5 ft. long, con it appear tained 150 & 140 ppm Cu to be too AAS analysis), 20 & 300 lean to ppm Cr, 1% Ti and greater encourage than 1% Ti and a trace of prospec Ag, respectively. Kac- ting." Kevett (1971) reports that MacKevett, a select grab sample of a 1971, p. 0.5 ft. wide quartz vein 44. contained 500 ppm Cu. Assay of two grab samples from stained zones gave 100 and 700 ppm Cu, 150 and 100 ppm Ni, 700 and 30 ppm Cr and 0.5% and 1% Ti, respectively. . 74 Triangle Mo Head of A few hundred pounds of None recorded MacKevett, No sign Island Queen molybdenite was miner. 1971, p. 78, of work Inlet. from the island in 01 e location no. ings day. The island is nom- 36, found posud of fine-grained Rossman, during a granodiorite cut by s 1963, p. K- 1966 exa . aplite dikes. . 49. mination ^ of the island. . 75 Gable Cu, Ag, East of Site til: Joint coat'.ngs None recorded Site 81s 1966, composite MacKevett, Site #1: Mountain Mo, W Car roll of secondary copper grab sample yielded 1,000 1971 and minerali Glacier minerals of unknown ex ppm Cu (spec) and small a- this in zation pro 10 mi. tent in diorite werts re mounts of Ag and Mo. In vestigation. bably local northwest ported in 1966 betwu in 1977 follow-up, 0.7 foot and limited Table C-58. --Muir province, Muir Inlet favonible area, occurrences not discussed in text, cont. No. on Main Source of pidto IV Commodity Location Description of deposit Mining Claims information Remarks 'J'j, cont. of Bruce 4300 arid 4500 ft. eli. channel across shear zone Site »2: Hills. In Follow-up in 1077 re yielded 250 ppra Cu (AA) and area con cludes crest vealed copper stainec; 7 ppm Ag (upec), while a high taining and weat side quartz diorite float grade grab yielded 8,000 ppm significant of high ridge. in talus leading to a Cu (AA) and 5 ppm Ag (spec). Cu, Mo, Ag 0.7 foot wide shear Site «2 area 1975s 7 grab and W sug zone with quartz samples ranged in assay value gests that O stringers and copper up to 970 ppm Cu (AA), 3 ppm the area I sLains at 4475 ft. ele. Ag (spec), 200 ppm Mo (spec) be lween there Nc stained float above; and 150 ppm W (spec). and Ltrucfi 00 talus and snow belovt Mil Is might One piece Cu stained well have float 2,50O ft. below further in in gully loading fron vestigation. inunodiave area. Site «2 8,000-9,000 ft. boui-.heast of sifcu #ls Thin iron sulfida joint coatinys in qu..rtz diorite cropping out. above a snow field <.:>d also on the mountainous r;Ulo ii,i>00 feet bolo-r. \_/ All sample values cited wore obtained from uemiquanti tative spectrogr.tohic analysis, unless noted otherwise. Remainder of Muir province The bulk of Muir province/ excluding the Muir Inlet £-a.\fc>raV*I« consists of Silurian through Permian hornfels, schists and, in places, limestone or volcanic rocks intruded by Tertiary and Cretaceous granitic plutons with predominent east-west trends. In the northwest portion the structural trends are more northwesterly. Plate III shows the area and figureC-2 shows the location of important prospects. The most significant mineralization found to date in the area are hydro- thermal quartz-sulfide veins containing copper/ lead/ zinc and silver intruding andesite, graywacke, limestone/ and hornfels located near Mount Brack. This occurrence may prove to be more extensive and higher grade with additional prospecting. This area has seen little pros pecting/ particularly the rugged/ remote alpine area along the monu ment boundary. No claims have been located in the area. The area < has potential for the discovery of volcanogenic (particularly volcanic rocks of Permian age the age of the Orange Point deposit volcanics)/ porphyry/ vein-type/ contact or replacement-type deposits but is not well enough known to accurately assess this potential. Mt, Brack zinc-copper prospect The Mt. Brack prospect is located about 3/4-mile easterly from Mt. Brack. It consists of hydrothermal quartz-calcite veins from 0.1 to 1.8 feet thick containing chalcopyrite/ sphalerite/ lead sulphide/ pyrite arsenopyrite/ and ankerite conformable hosted in Devonian and Permian andesite/ graywacke/ limestone/ hornfels and siltstone. Most of the C-319 I veins strike north and dip easterly. Altered zones in the area are sparsely mineralized (Samples 6S11B-6S122). Figure C-2 shows the prospect location, figures S67 and @68 show the sample locations, and table c59gives the analytical results. The veins contain up to 1.3 Figures C-67 and C-68, and table C-59 near here percent copper, 0.9 percent lead, 4.2 percent zinc, 0.7 percent antimony, 70 ppm silver and traces of gold. The veins could not be traced more than a short distance because of scree or snow cover. Individual veins are not high enough in average grade or extensive enough to approach being economic, and they are not close enough together to be mineable as a unit. The veins blend in with the gray-brown country rock and close scrutiny of the general area, particularly the cliffs to the southeast, could reveal more significant mineralization. Other prospects or mineralied zones in the remainder of Muir Province Information on the remaining prospects or mineralized areas in the remainder of Muir province is given in table C-60, and the locations are shown on plate III. Table c-60 near here C-320 Base from U.S. Geological Survey 1.63,360 Skogwoy A-4 1972 EXPLANATION Glacial ice and permanent snowfields Kggd Biotite-hornblende quartz diorite (Cretaceous) Biotite-quartz-feldspar hornfels, schist,semischist and phyllite Contour interval Marble (Permian) 100 feet 6SI15 Channel,chip or grab sample location 0 1000 2000 Assay data given in table C-59 i I I Feet I 1 i Meters 600 Figure O67Mt. Brack zinc-copper prospect,sample locations C-321 - f { f Uo 581498^ \ I ^9 cc \ A c. A Do IT 7A T .DotHoA c& t A f\ A" A T/\ v , - 70 5SI45A fl 551478-^1 \ I | 551458-^/^531468 / X 5SI48B * ^ 5S|43A 4.60 \ 5SI44A o X ^^.^ M / \ I TX 5SI44B / 5SI43B to to EXPLANATION stone and graywacke y predominantly covered £>y talus y60 Strike and dip of bedding 70 Quartz-calcite vein with sulfides, "*Vw showing dip. The veins are confonn- * » ' able with the host rocks Contour interval / 5SI45A 1 A" A Channel sample of vein 25 feet <£ limit of snow cover, 0 5 lO / 5SI45B X" Cnanne l or grab sample of host rocks Ii 1 1 i 1 J 'ee* / of vein 1 I i meters / 0123 s" Assay data given in table C- 59 Mopped by J.Still and A.CIcugh, august 13" Figure C-68 Mt. Brack mineralized zone, sample locations -t 3. Tt vj Q.«>=» J J3L 4; O o ^Vn O O "tow O a i a. O Vo n n O Vn XT Cr CD 4- cr O ro o f\) "oo 00 O o o tfT> to i J ^ O VJ 0) CQ o .0 CD 00 co oc o vn CO vT> in 10 vO C-323 \ or TT (97-7N M O// O/ (UU) 9|dlUD$ qj6u9~ Table C-60. Remainder jf Muir province, occurrences not discussed in text. No. oo Name of Main Source of Plate IV Prospect Commodity Locationit ion Description of deposit Mining Claires information Remarks 76 Casement Mo Casement Molybdenite-hearinf float None recorded MacKevett, "Location Glacier Glacier was found on moraine of 1971, p.74, doubtful", moraine . moraine, Casement Glacier by Ohio location no. MacKevett, about 1 State Univ. glaciologists 9. 1971, p.74. mile south of Coleman Peak. O 77 West of An Approx. 2 Arsenopyrite, chalcopyrite None recorded A 2-ft. channel sample MacKevett, I pyrlte, pyrrhotite and taken across an Iron- CO McBride miles south 1971, p.39, to Glacier east of traces of gold occur in stained zone in marble 56, 66; en Black Mtn. ankeritic zones near an contained 0.003 oz. Au location no. at the edge irregular, interfingered per ton, 13,000 ppm Cu, 10. This of McBride contact that marks a 200 ppro 7.n (all AAS Investigation. Glacier at facies change between analysis), 15 ppro Ag, an elevation marble and phyllite. A- 7000 ppm As, 5 ppm Mo of about bout 10 separate zones and greater than 5000 2500 ft. are present and each is ppro Mn. Four other less than 10 ft. wide and channel samples, ranging less than 100 ft. long. in length from 1.0 to The zones are copper- and 2.4 ft., taken across iron-stained and are con similar zones in marble formable with the bedding contained from 20 to 55 of the metasediroentu. One ppm Cu, from 10 to 80 zone forms the hanging ppm Zn (a]1 AAS analyses) wall of a 5-ft. wide ande- and N to 10 ppro Mo. Mac .site dike that contains Kevett (1971) reports that chalcopyrite and pyrite. a select grab sample of sulfide-bearing rock con tained 0.088 oz. Au/ton (fire assay atomic ab sorption method), 7,000 ppui As and 150 ppro Cu. A 2-ft. channel taken across an ankerlte zone contained 0.0088 oz Au/ton (fire assay atomic absorption method) and 100 ppro Cu. Table C-60. Remainder of Mulr province, continued. Main Source of Commodity Location Description of deposit Mining Claims information Remarks 78 West of N 59° 9' 40" Sulfide band 5-10 feet None recorded Anthony, 1977, Rlggs W 136* 18' wide in cliff fact too written Glacier steep to reach. communication. O to to I/ All sample values cited were obtained from semiquantltative spectrographic analysis, unless noted otherwise, North Chilkat sub-province Miller Peak-White Glacier area The Miller Peak-White Glacier area is 11.5-miles long, from one-bo-five miles wide, and is located between White Glacier and Miller Peak. Plate III shows the area and figureC-2 shows the important prospects. The area below timberline is mostly covered with heavy brush and timber, and is difficult to traverse, while the area above timberline is only moderately difficult to traverse. The area is predominately composed of a Permian andesite unit located between a limestone argillite unit on the west and a cherty limestone siltstone unit on the east that is intruded by a small granitic Tertiary plug. The most significant mineralization found in the area consists of a pyrite chert zone containing sphalerite, chalcopyrite, and trace amounts of native silver and gold located in limestone at the number 2 area of the White Glacier prospects. The number 3 area of the White Glacier prospect consists of pyritized zones in andesite containing slightly anomalous amounts of zinc, lead and gold located in a volcanic unit similar in age to the unit that contains the Orange Point massive sulfide volcanogenic deposit. Other prospects in the area are the Sandy Cove prospect consisting of an adit driven along a narrow discontinuous altered-zone quartz-vein system in granitic rock that contains low-grade copper, gold, silver and C-327 tungsten; and the Miller Peak prospect with potential for strata-bound quartz-calcite-chalcopyrite veins in limestone. While the above prospects, as they are now known, are too small and low grade to exploit economically, they and the geologically favorable area that contains them present a target for additional exploration. Additional strata-bound, vein or contact-type deposits potentially could be found in the area. White Glacier mineralized areas The White Glacier prospects are located between 1/4 and one mile north of the face of the White Glacier (1975). In 1966 the U.S. Geolo gical Survey found three areas where sampling indicated ore metal mineralization: the number 1 area contained traces of gold and 150 ppm copper; the number 2 area contained up to three percent copper, 0.05 percent zinc, traces of gold, and 15 ppm silver; and the number 3 area in volcanic rocks contained two percent zinc. Bureau of Mines 1 investi gations in 1975 and 1976 were confined to the number 2 and number 3 areas because of stormy weather. Figure C69 shows the area locations, geology and sample locations; and table C61 gives the analytical results. Figure G69 and table S61 near here Bureau of Mines' investigation of the number 3 area disclosed andesitic iron-stained zones hundreds of feet in width containing disseminated and occasional small pods of pyrite hosted within a Permian section of volcanic rock at least a half-mile in width. These zones, C-328 I36°55' 58° 50' Base from U.S. Geological Survey 1 : 63,360 Juneau 0-6, 1972 EXPLANATION Thin-bedded limestone and Cherty limestone and siit- argillite (Permian) stone (Permian) Basalt or andesite Contact, dashed where con (Permian) cealed, generalized from 6SI26-I29 X Sample location plate I Assay data given in table C-61 Figure C-69 White Glacier zinc-copper prospect, mineralized areas and sample locations 0329 Table C-6/ Assay Analysis PARTS Sample Length Aft- A. A, Sample ^Type Feet (m) Pb M Description 3.0 22O 70 Stfh ft ,6 10 I' l^SMSuT 370 >^p 6? C noco ^.30 #0 2-0 3O) IfcO f «.i'*\./iw o 30 I 80 L zco to co VSJ \2 3. -7 MfT 260 O ro /5'5" M 20 .05 10 M M JO !6i 1Q_ go ico 200. 'A. UfL To 30 L 2O) SO iSi /fl-3 ICO ^2a 30) up to 1,000 feet long, contain disseminated and small pods of pyrite. Nine spaced-chip samples across the zones from seven to 60 feet long contained up to 140 ppm zinc, 30 ppm copper, 80 ppm lead, 50 ppm molyb denum, and 0.05 ppm gold. Reanalysis of the original 1966 Geological i i Survey sample taken in this area indicated only 80 ppm zinc, and not the itwo percent reported in Professional Paper 632. Slightly anomalous !lead, zinc, and gold values may indicate some potential for volcanogenic- ,type mineralization in the area. , Investigation of the number 2 area indicated an iron-stained zone j (about eight feet across in Permian limestone, near a contact between the |limestone and volcanic units, that consisted predominately of pyriti- |ferous chert containing chalcopyrite, sphalerite, traces of native silver I land gold, ankerite, barite, celestite, strontianite, and witherite. The ! ^mineralization is probably strata-bound. To the south the mineralization i |is truncated by a mafic dike and to the north by cover. Figure C-70 shows !the mineralized zone and sample location, and table C-61 gives the analy- ;Figure C-70 near here tical results. Continuous chip samples across this zone ranging in length from 1.9 to 6.6 feet contained up to 4.5 percent zinc, 0.19 jpercent copper, seven ppm silver, 5,000 ppm barium, and 5,000 ppm strontium. Although not .of economic grade or size this concentration of mineralization encourages exploration in the area for higher-grade more C-331 El. 261 Oft. o; U) ! U) ! EXPLANATION to Limestone (Permion) Iron-stained limestone containing pyritiferous chert and sulfides Vertical mafic dike \5SI86 Chip sample location, length to scale Assay doto given in tobleC-61 mopped by J. Still and J. Rataj , August 1975 Figure C-70 White Glacier zinc-copper prospect, area no. 2 9-1267 extensive deposits. Further investigation of the area in which the number 2 mineralized zone is located was hampered in 1975 by constant scouring of the gullies to the north and south by ice avalanches from the hanging glacier just to the east. However, an investigation of the area in late August of 1977 revealed several iron-stained zones i | just to the north of this area exposed by receding snow. Stormy I weather with high winds prevented landing at natural helipads that i ! | were not exposed to the glacier's ice fall. The limestone andesite contact near which the above prospects 10 are located extends for miles and is a favorable environment for i stratabound deposits. 12 13 15 22 23 C-333 9-1267 Sandy Cove gold-copper prospect The Sandy Cove prospect is located on the northwest shore of Sandy Cove at an elevation of about 115 feet on a south-facing hillside, partially covered by vegetation and soil. Gold, copper and silver i values occur in discontinuous quartz veins and adjacent altered zones ! | I mainly in quartz monzonite and monzonite that forms small masses in a j i predominately limestone terrain. Four claims were staked on the ' prospect in 1933, according to the Juneau Recording District claim ; records. When G. A. Nelson visited the property in 1935, Wolf Creek 10- Mining and Exploration Co. had driven a 25-foot long adit (Nelson, ! | 1935). In 1936, Reed investigated the prospect and the Glacier Bay ; i Mining Co. was continuing development (Reed, 1938). A compressor shed ( i 13 had been constructed below the adit at an elevation of about 30 feet, i A surface tramway connected this structure with a loading shed located 15 at tidewater. By 1937, the adit had been driven to its present length I of 110 feet. The only recorded production was a four-ton smelter test . shipment made prior to 1938. In 1966, the U.S. Geological Survey samp led and mapped the adit and surface altered zones, and collected soil [ samples (MacKevett and others, 1971). The prospect is not actively held in 1978. The adit was mapped and sampled during the present study and the assay results obtained confirm those cited by the previous inves tigators. Figure C-72 shows the location of the adit, figure C-71 shows the adit sample locations, and table C-62 gives the assay Figures C-71 and C-72 near here C-334 5SI36 5SI35 EXPLANATION Quartz monzonite ft monzonite (Tertiary) zone with quartz veins, showing dip. Contains sulfides as disseminations and in massive discontinuous bands Channel sample location, 5SI32 length to scale ^Timbers Elevation of portal Assay data given in table C-62 opp. 145 feet o 5 10 15 Samples 11 I ' ' 5K058-059 located 100 ft. I meters east > Mapped by J. Still and J. Rataj, July 1975 Figure C-71 Sandy Cove gold-copper prospect, adit sample locations C-335 135° 55' 58° 45' EXPLANATION Quartz monzonite (Tertiary) Foliated biotite hornblende grano- diorite (Cretaceous) Limestone, siltstone, and argil life (Permian, Devonian and/or SHur- ian) Includes areas of cover Sandy Cove adit (Fig. C- Contact, generalized from plate I o; i w, U) OV 7K086 Sample location X Assay data given in table C-63 .5 mile I ' ' kilometers 0 .5 I 1.5 Contour interval 100 feet Base from U.S. Geoi. Survey h63,360 Juneau C-6, 1966 Figure C-72 Miller Peak copper prospect, sample locations. Also shows the location of Sandy Cove adit 9-1267 i results. The adit is driven on a discontinuous altered zone striking north- 1 j j east and dipping steeply east. The altered zone is from 0.2 feet to 4.5 2 ! i Table C-62 near here 0337 Table C-&Z Assay data } 60*^3 - Copper p. \o+3~ Analysis p«r~ Sample Length Spec.. -!/ fl.o (-0.6) so /s- N 00. 10 /u /V o w I 05" u> 55/325 Do. A; A; A; N CJ 00 Oo. ,200 A; /u N .10 55 f 33 A Da U£. A; Jbi A; L. ^L /S" 10 /u N 55/33C Do. Ao 100 o /OO /\J AJ 10 J3 0. 2 - Sc; / f i?/e> i/c /'/» . AS- 15" /3V* 00. U loo /o 10 Ool Da 00. ISO 3o 10 70 L I/O*-!. 1.5- 300 AJ A; to ,0? />*. 60 A) On. tyooo ISO 70 33 1.75* 5" 005" 55/35(1 Do. 10 IV n; Co. soo 10 n) f\J 10 ?-oni-t 55/366 Do. l.o oo A/ .2X2. Oo. no IS 1- A/ /u .ol Table C-£O. Assay data> Co\/o $old( - Copper pr0s^-f->Co/7-r- ?.*.<* 2- Analysis Sample Length _/ms Color. 3> Sample. Type Feet (m) Cu I Pb Mo Desription samples Chi? 3- 2 (l.o) IO 20 - Do. 1ST fi) by X-ftn* ' 2J Lo<*/Qt~ i?^ o 3f Sam pi l?u U) Specs and L- 9-1267 feet wide and contains quartz stringers and veins up to 2.0 feet j wide. Chalcopyrite and pyrite occur as disseminations in the quartz i i veins and altered wallrock, and in massive discontinuous bands up to j I 0.6 foot wide in the quartz. Scheelite is also present in some ! sections. Alteration products in the zone include chlorite, epidote, : sericite and hydromuscovite. The quartz monzonite and monzonite is i locally silicified near the quartz veins. The gold values have an ; i erratic distribution, with the best values obtained from at or near the j face of the adit. An 0.8-foot channel taken across a quartz-sulfide j i vein about 10 feet from the face of the adit contained 0.333 ounces i gold per ton, three percent copper and 1.75 ounces silver per ton. | 12 The samples collected in the adit contained as much as 159 ppm t I tungsten, 70 ppm molybdenum, 150 ppm bismuth, 220 ppm lead, - 1 and 300 .ppm arsenic.------The 110-foot long altered zone had ! average assay values of 0.019 ounce gold per ton, 0.18 percent copper [ i and 0.16 ounce silver per ton over a four-foot mining width based on 18 samples. According to Reed's map of the prospect (Reed, 1938), the face of the adit is about 100 feet from the limestone contact. The best gold values were obtained from at or near the face of the adit, so the mineralized altered zone could have a greater e:ctend than that exposed in the adit. Samples were collected from an altered zone approximately 100 feet east of the adit at an elevation of about 225 feet near the limestone contact (5K058 and 059). The mineralization is similar to C-340 9-1267 that found in the adit 'but the metal values of the samples were low. Other veins were found northwest of the adit forming what | appears to be an en echelon pattern trending northwestward. A 5_ I select grab sample from a sulfide-rich quartz vein/ about 100 feet west of the adit, contained 0.588 ounce gold per ton/ greater than 10 percent copper and 0.583 ounces silver per ton (MacKevett and , | others/ 1971). | , j Rossman (1963b) reports that samples from some of the altered i , 0_ j zones contained from 0.001 to 0.003 percent 11303. The Wrights (1937) i state that deposits of pyrrhotite containing some copper and nickel i occur near Sandy Cove. 15 18 23 23 C-341 Miller Peak copper prospect A float sample collected by the U.S. Geological Survey in 1976 from a stream draining the northwest side of Miller Peak contained 1.2 percent copper and a trace of silver. Follow-up of this sample in 1977. indicated a series of widely-spaced quartz-calcite veins containing chalcopyrite and malachite as the probable source. Figure C-72, previously cited, shows the area and sample locations. These veins appear to be conformably hosted in limestone or marble of which the northwest side of Miller Peak is composed. However, relict layering in the host rock is at best vague. A series of dikes and ankerite layers up to 10-feet thick also appear to be conformably hosted or follow relic layering. One vein was located in the footwall of an andesite dike; others are located in the limestone. The veins contain ankerite, biotite, chlorite, albite-oligoclase, sericite, calcite, pyrite, chalcopyrite and malachite, and can be traced for hundreds of feet along strike. Channel samples of the veins ranging in thickness from 0.75 foot to 0.8 foot contained from 0.42 to 1.5 percent copper and traces of silver. Table G63gives the analytical results. Table G63near here This area was only briefly examined and although the veins, as they are now known, do not approach being economic they and the surrounding C-342 Tabled~63 AssaV dqtq j>^7/e/- Peak copper pro*p*c± Analsis Par +£ Somple Length 5fec. Sample Type Feet (m) Cu Description to os) ^Z Sul fr do. * do. 2- lljOOO ^ o 1 area warrant a more thorough examination. Reconnaissance sampling by the U.S. Geological Survey during the present investigation revealed pervasive geochemical anomalies in the Miller Peak area, with stream sediment samples markedly anomalous in copper, lead, zinc and silver. (See Geochemistry section of the report.) The remainder of North Chilkat sub-province The mineral occurrences located in the remainder of the North Chilkat sub-province, excluding the White Glacier Miller Peak area are discussed below. C-344 Mt. Merriam area In 1966 a 35-square miles area east of Queen Inlet and north of Tidal Inlet, in north-central Glacier Bay near Mt. Merriam, was closely- spaced stream sediment sampled by U.S. Geological Survey geologists. Detrital sediments and extensive carbonate rocks intruded by granitics and cut by mafic dikes were mapped by Rossman in 1949 and 1951 (Rossman, 1963) and modified by MacKevett and others (1971) . Volcanics are present in the northern part of the area. Considerable faulting has occurred. Conspicuous iron-staining has been described as tactite associated with igneous-sedimentary contacts. Most of the 1966 stream sediments were reported to be anomalous in strontium and lightly anomalous in molybdenum. Nineteen of the 1966 sample sites were resampled by the U.S. Geological Survey in 1975, along with 26 new sites. High strontium results were repeated generally at * resampled sites and persist throughout the area. Measurable molybdenum (5 ppm), however, was not detected in any of the 1975 samples. Stream-sediment sampling (1966 and 1975) pointed out no specific targets. No mining claims have been recorded in the area. Known mineralization in the northwestern part of the area, the presence of tactite skarn zones, and an aeromag anomaly suggest a body that is not exposed. Tactite skarn zones containing magnetite were found by the U.S. Geological Survey in 1966 in volcanic and alaskite host rocks exposed in sea cliffs three miles west of Mt. Merriam. Ground magnetometer traverses taken along the beach, thence up a northeast ridge to the C-345 1740-foot elevation, indicate the probability of more magnetite-rich zones or pods concealed beneath cover of glacial drift which mantles flatter areas. Seven select grab samples taken by the USGS in 1966 of magnetite-skarn pods in felsic rocks or pyrite-rich zones in nearby metamorphics contained copper values ranging up to 300 ppm, and all but one contained more than 10 percent iron. A quantitative chip sample taken across the 18-foot width of the richest appearing magnetite occurrence in the sea cliffs assayed 23.4 percent total iron; and 0.11 percent, 1.54 percent and 0.36 percent P205,S,and Ti02/ respectively. Brief traverses by USBM engineers in 1976, to the east of this locality and higher on the ridge of Mt. Merriam, indicated that tactite or skarn zones are also found in the carbonate host rocks of that area, a mile and a half east of the beach. In this vicinity, a few magnetite- rich pods were seen. Three pods were sampled, and numerous others were inaccessible. One, 15 by 25 feet in outcrop at an elevation of 3,100 feet, assayed more than 20 percent iron in a composite chip sample. A two-foot wide pod at the 2,600-foot elevation assayed more than 20 percent iron and 0.28 percent copper. A third smaller pod, farther west, contained similar iron values but lesser copper. Other pods or zones were seen in cliff faces. Bureau engineers in 1977 took three 20-foot spaced-chip samples on the crest of a.conspicuously iron-stained 2,500-foot knob, three miles south of the summit of Mt. Merriam, one of several heavily-stained rock masses in the vicinity. The rocks were hornfels containing finely C-346 disseminated iron sulfides. Assay returns indicated five to seven percent iron and 700 to 1,500 ppm strontium. Each assayed 30 ppm molyb denum. Information obtained from two localities along a discontinuous but conspicuous iron-stained zone following the prominent ridge southward from the east side of Mt. Merriam, according to George Moerlein (,\968b) / : consisted of argillite with 10 percent pyrite cubes, but with no other sulfides. Rossman mapped a contact between granitic intrusives on the west and sedimentary rocks on the east not far from this ridge. Other mineral occurrences in the remainder of North Chilkat sub-province Information on the other mineral occurrences in the remainder of the North Chilkat sub-province is given in table G64 t and the locations are shown on plate III. Most notable among these is the Berg Creek chromium anomaly. Table C-64 near here C-347 Table C-64. Remainder of North Chilkat subprovince, occurrences not discussed in text. No. on Main Source of plate III commodity Location Description of deposit Mining claims Samples I/ information Remarks 79 Berg Creek Cr Head of Berg Cr. Several square-mile(?) None reported in 1966 stream sediments Lathram and No ultramafic above the 1,900 area of Devonian and/or within the monu yielded 700 to 1,350 others, 1959 rocks which ft. elevation Silurian volcanics and ment. ppm Cr from tributaries (1-303)j Mac- would normally near the extreme siliceous argillite, along several miles of Kevett and be the host of eastern monument through stream sediment Berg Cr.; 1976 follow-up others, 1971, a chromite boundary. analysis indicated as stream sediment samples p. 4, location deposit were having very high back yielded up to 2,000 ppm Ej this investi identified, ground in chromium. Cr and contained chromite gation. although in O Deposit not seen, but both in magnetic and non spection of I best values from south- magnetic fractions. outcrops at u> £t flowing tributary I 1] to Fuchsite, a chromium higher eleva 00 2 miles west of monument muscovite, also present tions was boundary flowing from in vicinity in calcareous limited by under a glacier whose float. foul weather snout is covered by a and snow huge slide of volcanic cover. rocks. 80 Mt. Young Cu, Two miles north Metamorphic rocks includ None reported. Two 1966 samples, one MacKevett and Most of this (#1) Zn, of summit of Mt. ing metavolcanics cut by select sulfides replacing others, 1971, area was ob Au, Young in head of mafic dikes, small gran metavolcanics and the p. 41, 1oca- scured in Ag drainage /lowing itic plutons, shear other a grab of altered tion Hj this 1976 by west to Adams zones and quartz veins. slate and hornfels yielded investigation, glaciers and Inlet. Carbonaceous shale up to 1,500 ppm Zn and was extensive seen in 1976 to contain slightly anomalous in Ag, snow fields. irregular discontinuous Cr, Cu, Mo, Pb, and V. pyritic-stained zones. One 1976 sample, a 15-ft. chip on S-lst. intervals across one of several pyritic stained zones in local carbonaceous shale substantiated 1966 values but also yielded 0.1 ppm Au and 20 ppm Ag. A grab of float from a similar zone under a glacier con- . tained 0.1 ppm Au and 50 ppm Ag. Table C-64. Remainder of North Chilkat subprovihce, occurrences not discussed in text, continued. Main Source of commodity Location Description of deposit Mining claims information Remarks 81 Mt. Young Cu, Three and one- 1966 ankerite zones up to None reported. 1966 samples of ankerit- MacKevett and Most of this (#2) Au, half to 4 miles 30 ft, thick cutting gran ic altered zones in grani- others, 1971, area was obs- Ag north-northwest itic rocks containing tics yielded traces of Cu,. p. 41, location cured in 1976 of summit of Mt. anomalous Cu, Mo and Au. Au and Mo. 1976 24-foot #2$ this invea- by glaciers Young 1976 site somewhere near chip sample at *j-foot in- tigation. and extensive 1966 locations( highly tervals across heavily snow fields, hydrothermally-altered pyritized zone yielded 350 rocks of volcanic ppm Cu 82 Casement Cu Moraine at an Skarn boulders containing None recorded. ~ G. A. Moerlein, Glacier elevation of appr. 5% c ha 1 copy rite were 1968a. moraine appr . 1 , 800 found at this locality. A ft. , south of check failed to reveal the a small lake source . east of Red Mountain. 83 Nunatak on Zn Nunatak on Case Quartz ankeritic veins as None recorded. Select sample of veins MacKevett, 1971, Casement ment Glacier at much as 1 ft. thick within contained 300 ppm zinc. p. 54, location Glacier an elevation of 10-15 ft. thick altered no, 3. '1,000 ft. zone in thin-bedded horn- fels. 84 Bast of Cu Located between Altered zones 5-30 ft. :None recorded. A composite and a select MacKevett, 1971, Casement Casement Gla thick near granitic rock sample of altered rock p. 41, location Glacier cier and Van hornfels contact cut gra contained up to 500 ppm no. 4. Horn ridge. nitic rock. The zones copper and 5 ppm molyb contain scattered pyrite. denum. Table C-64. Remainder of North Chilkat subprovince, occurrences not discussed in text, continued. No . on Name of Main Source of plate III prospect commodity Location Description of deposit Mining claims Samples I/ information Remarks 85 Adams inlet Cu North shore of Lava flows of amygdaloidal None MacKevett (1971) reports MacKevett, 1971, Adams Inlet basalt up to 15 ft. thick that a select grab sample p. 41-42, 73, about 3 miles are exposed for 500 ft. of 4-ft. wide altered 78, location from the en along the shore. Pyrite, zone contained 1 ppm Ag, no. 5. trance. chalcopyrite and pyrrho- 300 ppm Co, 500 ppm Cu O 1 tite oocur along frac and 30 ppm Mo. Five u> tures in the lava and spaced-chip samples, 44 t_n near altered basalt to 110 ft. long, had Q dikes which intrude the values ranging from 150 flows. Pyrite, ilmen- to 300 ppm Cu and » to ite and magnetite are 30 ppm Mo; one sample disseminated throughout contained 10 ppm Sn. the dikes. 86 Entrance of Mo North shore of Molybdenite occurs as Ten claims were MacKevett, 1971, Adams Inlet Adams Inlet at fractured coatings in staked in the p. 78, location the entrance. metaraorphic rocks, vicinity in no. 22; Budding ton mainly hornfels and 1912. and Chapin, 1929, tactite. p. 330; Smith, 1942, p. 178; Juneau Recording District claims records . 87 South of Tidal Cu Three miles Pyrite, chalcopyrite and Claims for cop- MacKevett (1971) reports MacKevett, 1971, Inlet south of pyrrhotite occur in sever- per reportedly that a select grab sample p. 50, 79, loca Tidal Inlet. al thin quartz veins in staked in the of a sulf ide-bearing tion no. 41; marble near a contact vicinity, quartz vein contained 0.1 Hright and Hright, with hornblende diorite. ppm Au (fire assay atomic 1937, p. 221-223. absorption method), 1,000 ppm Cu, 300 ppra Ni and 300 ppm Co. Table C-64. Kemainder of Nor.th Chilkat subprovince; occurrences not discussed in text, continued. No. on Name of Main Source of plate III prospect commodity Location Description of deposit Mining claims information Remarks 88 Sandy Cove Marble Bast shore of Fine-grained marble up to Three claims for Burchard 41920) reports MacKevett, 1971, marble pros the cove south 500 ft. thick is exposed marble reported that a sample of the p. 85) Hodge, pect. of Sandy Cove. along the shore. The ly staked in the marble contained 96.16% 1944, p. 18) marble is intensely frac vicinity. CaCOj, 0.89* MgCo3 and Buddington, 1926, tured and is cut by dia 2.56% clay minerals. p. 61) Burchard, O base dikes. 1914, p. 98-99; I U> Burchard, 1920, p. 41-42. I/ All sample values cited were obtained from semiquantitative spectrographic analysis, unless otherwise noted. South Chilkat sub-province For the purpose of discussion the south Chilkat sub-province is divided into eastern and western portions; the eastern section consists of everything east of Glacier Bay, and the western section the remainder. Plate III shows the area, and figure C-2 shows the important deposits in it. The eastern portion consists predominately of Silurian graywacke, argillite, and limestone units intruded in the southeast by two small Cretaceous granitic plugs and in the northwest by two Cretaceous granitic stocks. The Exray claim staked in 1967 is located on brecciated zones and quartz calcite veins containing chalcopyrite in limestone on the Excursion Inlet Ridge. Here copper-gold mineralization is low-grade and the occurrence does not appear to be extensive. Outcrops are relatively sparse in this area and these have been moderately well explored by prospectors from nearby settlements of Gustavus and Excursion Inlet, and a number of claims have been staked. This exploration has not resulted in the discovery of important prospects. However, U.S. Geolo gical Survey geochemical sampling indicated significant geochemical anomalies in this area (see Geochemistry section of the report). The western portion of the south Chilkat sub-province consists predominately of Devonian and Silurian limestone, graywacke, schist, and schale or siltstone intruded by Tertiary granitics. The extensive limestone granitic contact zones in the area are favorable for the C-352 formation of high temperature contact-type deposits. The Alaska Chief deposit, the prospects on Willoughby Island where some very limited mining has occurred, and the prospect on Francis Island are probably all contact-type deposits. The most important of these is the Alaska Chief. Located some distance from intrusive rocks is the Dundas Bay altered zone which consists mostly of disseminated sulfides carrying low copper values in quartz semischist. Although too low in grade to exploit economically, its extent encourages exploration for higher grade mineralization. This area is not as rugged as most other areas in the monument and has been prospected since the 1890's. At that time, the area had much less vegetation than it does today. Additional prospecting along the limestone granitic contacts may reveal additional contact-type deposits. Alaska Chief copper prospect The Alaska Chief copper prospect is located at an altitude of 1,150 feet in the mountains west of Ripple Cove. The prospect was staked as the Alaska Chief #1 in 1899 along with seven other adjoining claims. In 1924 the Alaska Chief #2 was patented and is now owned by The Nature Conservancy. Plate III shows the prospect location. In 1966 MacKevett (MacKevett and others, 1971, pp. 45-46) mapped and sampled the prospect, and estimated 28,000 tons of rock containing one percent copper. A Bureau of Mines' crew briefly visited the site in 1975 and concur with this tonnage estimate. Since the 1966 sampling, the price of silver and gold has risen dramatically. The above inferred resources also average two ounces of silver per ton and 0.10 ounces of gold per ton. C-353 The prospect is located at a Tertiary-Cretaceous diorite contact with Paleozoic limestone. The intrusive contact and the relic bedding in the metamorphic rocks strike about N30°W and dip steeply to the southwest. The contact metamorphic rocks are chiefly hornfels with subordinate tactite and marble. Dundas Bay altered zone An extensive copper-bearing zone in Silurian quartz setumpchist that has sharp contacts with adjacent metabasalt is located along the east side of Dundas Bay. Figure O2 shows its general location. This zone is at least 100-feet wide and probably up to 1,000 feet wide in places, and extends for at least one mile. The Wrights (1937, p. 272) state that a number of mining claims were located on the east side of Dundas Bay for copper, lead, :zinc and gold. This zone was investigated in 1966 by the USGS (MacKevett and others, 1971, p. 48), in 1968 by Moerlein (1968a) and in 1975 and 1977 by this study. The following is a synthesis of work on this zone by the USGS 1966, Moerlein 1968, and by this study in 1975 and 1977. The zone trends in a northerly direction and contains disseminated sulfides, sporadically-distributed pods of sulfides with abundant secondary iron minerals, and a few quartz veins. The sulfides are mainly pyrite with minor chalcopyrite. Moerlein (1968b) reports a shear zone trending C-354 N45°W and containing chalcopyrite. His chip samples of this zone, one 35 feet long and the other 20 feet long, contained 0.510 percent and 0.340 percent copper, respectively. Geological Survey- and Bureau of Mines-measured chip samples of the altered zone contained up to 1,000 ppm copper, 230 ppm lead, 20 ppm molybdenum, and two ppm silver. Figure C-73 shows the sample locations, and tableC-65gives the analytical results. Figure G73and tableG65 near here The known mineralization extends for at least one mile and the extent of the mineralization to the north and south has not been determined. It is estimated from the limited sampling data that the average grade of the one-mile of zone that has been investigated is well below 0.1 percent copper. The only indications of higher grade mineralization were the shear zones reported by Moerlein. Although the grade of mineralization found thus far does not approach being economic, the size of the mineralized zone encourages exploration of this zone for higher- grade mineralization and of the area for higher-grade mineralized zones. C-355 Contour interval 100 feet Base from U.S. Geol.Survey 1 = 63,360 Fairweather B'l, 1966 EXPLANATION Approximate boundary of copper-mineralized area as deter- * - mined by brief examination. Open to the north and under cover to the south A5S2I9 Sample location Assay data given in table C-65 Figure C-73 Dundas Bay altered zone, sample locations C-356 17L' our t,' IN 07 yi cm \ b'h O JTi N Is S 00^ ?,/ M oar ' <* > i O'fr srt u Ot Ob " 07^ 01 S o N o OS ( sz 7*71 \\z<:s OZ J> 0/2^5 O O'g I o/ o/ ox/ UOjJdMOSSQ w ^ (Ul) yv \)V NOIT W SISA|DUV ADSS\/ 5^-^ 9-1267 Exray copper prospect i The Exray prospect is located on the ridge between the settle ments of Gustavus and Excursion Inlet, west of the entrance of Saw mill Bay at an elevation of about 2,700 feet. Chalcopyrite occurs i in calcite veins in calcareous argillite, in brecciated zones of limestone, and in limestone-calcite breccia veins. The ridge is largely covered by turf and the only mineralization ! i seen was that exposed by shallow pits, the only development of the ; i prospect. Between 1909 and 1942, 25 claims were staked in the vicinity of the prospect. The nearby canneries and sawmill in Excursion Inlet probably account for the high level of staking activity in this area 12 of few outcrops. In 1955-56, the prospect was staked as the Johnny 13 Boy group of two claims and the White group of twelve claims. P. R. Holdsworth and J. A. Williams of the Territorial Department of Mines examined the property in 1956 (Williams, 1956). The Johnny Boy claims were held until 1968. Eight claims were staked near the prospect in i 1962, and in 1967 the Exray group of four claims were staked for i copper, silver and gold. The latter group was held until 1971 when the locator dropped the claims. In 1968, the G.B. group of 36 claims were staked by Cyprus Mining Co., probably on ground north of the Exray prospect. Six pits have been excavated on the prospect and bedrock is exposed in five of these, though they are partially sluffed and the rock may 2-t not be in place. The poor exposure in the pits and the lack of out crops between the workings preclude determination of the structure of C-358 9-1267 j the deposit and the extent of the mineralization. Figure C-74 shows Figure C-74 near here the location of the prospect pits, figure C-75 shows the sample Figure C-75 near here locations, and assay data are given in table C-66. The highest copper Table C-66 near here content was found in select grab samples from the dumps. In-place measured samples ranged from 80 ppm to 4,300 ppm copper across widths :of one to six feet. A trace of silver was detected in one of the jselect grab samples but gold was not detected in any of the samples. A traverse was made north of the prospect pits"to a point opposite! i ithe head of Excursion Inlet. Several narrow quartz-calcite veins ! i iwere sampled but the metal values they contained were low. Near Peak ,3051, two miles north of pit no. 5, diorite containing approximately two percent pyrrhotite was exposed, but may not be in place. No sign !of claims or workings were encountered. Claim cairns .were seen near jPeak 3404, 1.2 miles south of pit no. 1. In the pass between this i 22 ipoint and the next peak south, an east-west striking dike swarm ij [Occurs. Several narrow, unmineralized quartz-calcite veins were noted i iat several localities in the pass. C-359 135° 35' 135° 30' \^^^^^^f^^ 58| 'f/j- 'Pi t" '';££; :'(ill;//>' 30 »* --," - A'rw '"/; *C.>''/. /I l"-", -" l.%.^~;a -;'// ;j\ \\ " ;v ; Mi EXPLANATION Foliated hornblende quartz Hornblende diorite and quartz Graywacke, argillite,calcareous 25' Large areas of the above units \ are covered with vegetation, al luvium, and colluvium ___ Contact, dashed where in definite Approximate limit of area investigated and sampled XPit no. 5 Location of prospect pit \ :-%:\Sag ://-; ^ Pits nos.1,5 and 6 shown in fig.C-75 -y^ :yv\^ :/.. M...:.i. \a> ^ 'v.^-a:/ >^ Contour interval 100 ft. 0 .5 I kilometers 0_-5 15 Bjse from U.S. Gecloqicoi S'-r/ey r 53,360 Geulcgy from Lathram and others, juneau B'S, 1966 Tod C'5, 1973 Mip 1303, 1959 5. Plate I Figure C-74 Excursion Inlet, area investigated and location of ______prospect pits______ "C-360 Pit number 1 Pit number 6 EXPLANATION ^fitf+F**^ /may not be in y^||||||?v/ place x5SI29 Itllfill Turf or talus Nj|;||||i:||;:|||||;|x7--not in place f\\ \ 1 I /y^) elevation Tx\\\; elevation 2800 ft. ss\^v Calcareous argillite (Silurian) Limestone; some sections contain lime - stone-calcite breccia veins with chafcopyrite (Silurian) Pit number 5 av /~7 Calcite vein, locally with chalcopyrite 5K 0 7 6 - 0 7 7____jpl||j| .Exray number 5 claim post N\\|// Dump « Channel or chip sample location, length to 5SI28 sca|e elevation 2780 ft. 5SI29 Select grab or composite grab 1 f sample location J, HH 5SI30 Assay data given in table C-66 elevation zsoo ft. 0 5 10 20 , ,! 1 1 feet 1 1 it meters Exray number 1 claim post 0246 Mapped by A. Kimball, J. Still, and J Rataj, July and Auguit, 1975 Figure C-75 Exray prospect, workings and sample locations V V ^"^ 4- vn J^ V> 0 s5 X ? > v \n I VI i o H o f g o Oc o 4- 4- c < <£ CL t Q. VO sQ. Oo Oo VO 2 X Ul O -to TO OS 4- en 'I 4; VJ 60 J5 X) O o C-362 Valley of Tears placer Rossman reported the presence of placer gold in the upper Dundas River drainage (Rossman, 1963b). The Valley of Tears placer claims numbers 1-7 were, recorded in 1963. Recording information states this group of claims is two miles south of Dundas Lake on the Dundas River. In the present study indications of placer activity were found 1.3 miles south of Lake Seclusion flate III) on a south-flowing fork of the Dundas River. A cabin containing mining equipment is located just south of the junction of a large west-flowing tributary to this fork of the river. In addition, claim lines and evidence of a former tent camp were found near the cabin. Lake Seclusion is locally called Dundas Lake. The location was described by Richard Dalton of Hoonah (oral communication, 1975). Nine 3- to 7^-pound grab samples of unconsolidated material were taken along a line that crosses the tributary stream and the delta on the north side of the tributary and east of the river. Sample sites were 15 feet apart for the seven samples across the tributary and beach bars on either side. The remaining two samples were of the delta area about 75 feet northwest. No samples were taken in the river because of high water. The samples were panned in the laboratory. All concentrates contained free gold visible under the binocular microscope. The individual concentrates as well as a split of the tails were fire assayed. The two assays for each sample were mathematically combined. All samples contained a trace of gold which calculated to approximately 0.5 to 1.5 C-363 cents per cubic yard. Petrographic examination on one sample showed that the heavy minerals were less than 0.5 percent. The locality is probably a mile or more from the nearest bedrock exposure. Site material consists largely of stream-worked glacial materials. The samples are strictly reconnaissance samples at the presiding water stage at the time of the visit. They do not quantitati vely represent the occurrence. Whether past production has occurred and how much has not been determined. Where mining may have occurred is not evident. Other prospects in the South Chilkat province The location of the remainder of the prospects in South Chilkat province is shown on plate III and pertinent information on them is given in table G67. Of note are the copper and silver prospects located Table G67 near here on Willoughby Island from which some ore was mined. C -364 Table C-67. South Chiikat subgrovince . occurrences not discussed in text. Main Source of commodity Location Description of deposit Mining claims ilesi/ information Remarks 89 North Mar Cu Pyrite occurs as dissemina A claim was reportedly MacKevett, 1971, ble Island tions in silicified marble staked for nickel. p. 44, location no. near mafic dikes, and in the 24; Reed, 1938, p. dikes. A 1966 investigation 69; Rossman, 1963b, did not confirm reports of p. k51. sulfide pods up to 1.5 feet wide and 15 feet long occur ring in the marble near the O dikes (Reed, 1938). I U)en 90 South Mar Cu Pyrite-rich impregnations None recorded, Ku.Kavett (1971) MacKevett, 1971, ble Island occur within silicified reports that four p. 44, 79, 82, marble near mafic dikes. select grab samples location no. 25; The dikes, which are up to from the mafic Reed, 1938, p. 69; 50 feet wide, contain dis dikes and silici Rossman, 1963b, seminated pyrite. fied contact zones p. k51. each contained 100 ppm Ni, from ' . 150-200 ppm Cu; and from 0.5-1.0% Ti. North and Marble 90 and Both islands are composed None recorded, MacKevett, 1971, South Mar 89 of medium-grained marble p. 85; Burchard, ble Island cut by numerous mafic dikes. 1914, p. 100; Burchard, 1920, pp. 43-44. 91 York Creek Cu North of At an elevation of 100 feet Four claims were staked MacKevett (1971) MacKevett, 1971, York Cr., about 15 widely-spaced in the vicinity between reports that a sel p. 42, 79, loca at an pyrite-rich quartz veins and 1899 and 1904. ect grab sample of tion no. 8; Juneau eleva- altered zones containing pods one of the quartz Recording District tion of of pyrite occur in hornfels. veins in hornfels claim records; Geo. 100 ft. The quartz veins are up to contained 150 ppm A. Moerlein, writ and be- 0.5 feet wide; the altered Co, 1,500 ppm Cu, ten communication, tween 400 zones are up to 50 feet wide, 150 ppm Ni, and a 1977. and 700 An iron-stained zone about trace of gold (fire ft. 1/2 mile long in siliceous assay atomic absorp limestone outcrops between tion method). A Table C-67. South chilkat. subprovince ,occurrences not discussed in text,can't. Main Source of commodity Location Description of deposit Mining claims Samples-- information Remarks 91, cont. 400 and 700 feet. The stained 20-foot long spaced zone contains an estimated 5- chip sample of one 10% pyrrhotite. of the altered zones in hornfels contained 50 ppm Cu and a trace of gold (fire assay atomic absorption method). Moerlein O I (1968b) reports that a sample from the cr> stained zone in lime stone contained 2,260 ppm Cu and a trace of gold. 92 North shore Mo North Sulfide-bearing greenschist, None recorded. MacKevett (1971) MacKevett, 1971, of Geikie shore of apparently large. reports that a select p. 79, location Inlet Geikie In grab sample contained no. 48. let about 10 ppm Mo and 150 ppm 2 mi. from Cu. the en trance at an eleva tion of app. 450. ft. 93 Shag Cove Cu Sulfide A mineralized zone in mixed None recorded. On the island a select This investigation minerali metamorphic rocks near a sample of a sulfide zation contact with a diorite body pod contained 1.5 ppm has been outcrops along the west shore silver, 260 ppm copper MacKevett and oth- found of Shag Cove. On the island (AAS), and 100 ppm co- ers, 1971, p. 51, on the the sulfides pyrite, pyrrho bait. At 1/2 mile location no. 49 smaller tite, malachite and bornite from the mouth of Shag of two are found in small pods in Cove a composite islands interbedded argillite and sample from the quartz near the quartzose graywacke. At 1/2 veins contained 1 ppm mouth and mile from the cove mouth silver, 330 ppm copper Table C-67. South Chilkat» aubprovince, occurrences not discussed in text, con't. No. on Name of Main Source of plate IV prospect commodity location Description of deposit Mining claims Samples I/ information Remarks 93, cont. h and l>i sul fides tend to be associated (AAS) and 100 ppm cobalt. miles from with narrow quartz veins in At l*t mile from the the mouth metamorphic rock, and at 1*1 mouth of the cove a -. of the miles from the cove mouth the select sample of a 6- cove sulfides are found in quartz- inch thick pyritic pod along its pyrite veins and in pyritic contained 3,000 ppm west side. pods within a sheared and copper, 700 ppm zinc, altered zone in quartzose 200 ppm cobalt, and 1 rocks. ppm silver. O I 04 Francis Cu Southwest A Cu-Zn-Ag deposit is located Two claims staked Assay of two samples MacKevett, 1971, p. "Prospecting U) Island shore of near the contact of quartz in 1923. of float from the 29, 39-40, 45, 55, the shear Francis diorite and marble, but is now shear zone gave the 73, 79, location no. zone might he Island covered by landslide debris. following results: 28; Reed, 1938, p. warranted, Bornite, malachite, sphalerite one contained 210 69; Rossman, 1963t>, but indica (?), tetrahedrite(?), and ppm Zn (AAS analysis) p. k51; Smith, 1933, tions are chalcocite(?) are irregularly and a trace of If; p. 323; Buddington, that -the distributed along a sheared the other contained 1926, p. 56; Juneau deposit is fault zone in tactite. 7 ppm Ag. MacKev- Recording District small." ett (1971) reports claims records. MacKevett, that a grab sample This investigation. 1971, p. 45. from the fault zone contained 7,000 ppm Cu, 1,000 ppm Zn, 200 ppm Sb. 150 ppm Bi and 1.46 ounces Ag/ton. 95 Northeast Cu Northeast Massive sulfides, including Eight claims MacKevett, 1971, This prospect side of side of pyrite, loellingite .(?), and .stained be p. 40, 44-45, 69, was searched Willoughby Willough chalcopyrite occur as replace tween 1833 and location no. 26; for but not Island by Island ments in limestone. The 1902. Reed, 1938, p! 70-71} found during at an deposit is 5 feet wide over an Juneau Recording a 1966 invea- elevation exposed strike length of 15 District claims tigation. of approx feet. At least three other records. imately similar deposits are reported 450 feet. to be in the same vicinity. Table C-67. South Chilkat subprovince,occurrences not discussed in text, con't. Main Source of commodity Location Description of deposit Mining claims Samples- information Remarks 95, cent. One of these deposits is explor ed by an open cut that is 30 feet long and 5 feet wide. 96 Northwest Ag Approx. A 1-foot wide vein of massive Two claims staked in Shepard (1926) reports MacKevett, 1971, This prospect side of 2 miles culfides occurs in marble at 1907. Property that a 1 foot sample p. 39-40, 45, was searched WiUoughby south nf the intersection of two lampro- bonded to the Tread- taken across the mas 49, 53, 69, for but not Island, the phyre dikes. The vein can be well Yukon Co. in sive sulfide vein con location no.. 27; found during O Smith northwes- traced for 100 feet across the 1925. tained 0.12 ounce gold Shepard, 1926, a 1966 inves I prospect; ternmost face of a bluff. A 44-foot per ton, 11.9 ounce 2 p.; Rossman, tigation. to CT> Treadwell point of long adit driven from a gulch Ag/ton, 13.4% Sb and 1963b ;. 00 Yukon Co. the is intersects one of the dikes 50 29.75% Pb. Buddington Reed, 1938, p. prospect. land at feet from its outcrop but no (1924) reports that a 71-72} an ele mineralization was found. Sul- sample from the pros Juneau vation of fides comprising chalcopyrite, pect contained 25% Pb, Recording approx. pyrite, tetrahedrite and an un 25% Sb, 1.74 ovmces District, plaim 450 feet. identified sulfide mineral occur gold per ton, and 42 records. in joints in the marble and ounces Ag/ton. along contacts of both dikes for a considerable distance away from the intersection. Some ore was mined from the prospect. 97 WiUoughby marble East Marble is exposed for 500 feet None recorded, MacKevett, J.971, Island shore of along the shore, up to an ele p. 85; Burchard, marble Willough- vation of about 70 feet. The 1914, p. ICOj prospect. by Island marble is cut by dikes and is Burchard, 1920, near Tri- jointed in places. p. 44-45. angula- tion station "Mars." Table C-67. South Chilkat subprovince, occurrences not discussed in text, con't. No. on Name of Main Source of plate IV prospect commodity Location Description of deposit Mining claims Samples-^ information Remarks 98 Southwest Zn Approx. 1 A 3-foot wide mineralized None recorded. MacKevett (1971) :MacKevett, 1972, "The deposit is of Alaska mile south shear zone occurs in granitic reports that a grab p. 53, 55, loca probably too Chief west of the rock. sample contained tion no. 30. loan to encour prospect Alaska 1,500 ppm Zn, 300 age exploratiorf Chief pros ppm Pb, 70 ppm Cu, MacKevett, pect at an and 0.2 ounce Ag/ 1971, p. 55. elevation ton. of 400 feet 0 CO 99 Storm's Fe Probably Reported to consist of 500- Four lode claims Reported analyses of Storm, 1917 (un Briefly search iron near south foot long string of magne recorded in 1903 5 samples taken published report ed for during prospect end of tite ppds up to 30 feet as Iron Mountain across the exposures titled "Dundas present inves (Dundas White Cap wide as replacement in »1 through #4. in 1917 indicate the Bay Iron Proper- tigation but Bay iron) Mountain limestone near an igneous magnetite to be quite ty"). not found and ridge, contact. Area of magne pure. Reported to may now be roughly tite exposed estimated contain no sulfides. covered by vege 4^-5 miles about 5,000 square feet at tation. MacKev northeaster time of examination in 1917 ett (1971) citaS ly of Pt. when exposures were probab both Rossman Dundas. ly better than now. No and Mertie as Elevation workings. sources of un probably published between references to m 1,500 and iron deposit .in 2,000 feet. this area. None visited tie deposit. 9-1267 Miscellaneous commodities ' Geothermal resources i ' 3 I Geothermal energy potential is subdivided into three types: 4 hydro-thermal convection systems or hot springs; hot igneous (usually | ! 5_ volcanic) systems; and conduction-dominated areas (White and Williams, 4 1975). One hot spring with small flow occurs in Glacier Bay National ' i 7 Monument on the east side of Icy Point about 0.8 km southwest along a the shore from the mouth of Kaknau Creek. The main area of flow is 9 about 100 m back from the high tide line. This spring has been known to i | ; 10 fishermen and is probably the poorly located spring in the vicinity of n Lituya Bay referred to by Waring (1917) and Miller (1973). An analysis ! | I 12 of water from the spring is given in table C-68. This analysis indicates i ; 13 that the water is probably of metamorphic origin and that no high i . ] '4 temperature system is present (Ivan Barnes, oral communication, 1978). TABLE C-68 NEAR HERE , 6 I Six hot springs are known on Chichagof Island south of the monument ., and several more are known elsewhere in southeastern Alaska (Waring, ?-_i917; Miller, 1973; Renner, White, and Williams, 1975). There are no 2] areas of recent volcanic rocks in the monument and it is unlikely that --, an area large enough to sustain a hot igneous system could have escaped notice. The possibility for an area in southeastern Alaska with a high n.. heat flow to produce an energy source has not been fully assessed. 7 -_ There is no indication that such is present and in any event, the C-370 9-1257 technology for utilizing it does not now exist (Mathenson and Muffler, \ JL975). 10 12 13 15 C-371 9-1267 Table C-68. Analysis of water from Icy Point Hot Springs/ -Glacier Bay National Monument, Alaska Field no: 77BJ010 Lab no: GT60BJ77 Location: Lat. 58°23 1 30". Long. 137°04'38" Temperature: 67°C; ph:^6.4; Specific conductance: 20,000 Analyst : T.S. Presser, U.S. Geological Survey/ Water "Resources -Division,- Menlo Park, Calif.; 12/77 Cations , mg/1 me/1 Anions , mg/1 me/1 SiO 68. HCO * M6. 0.2 £* Ca 800. 39.920 S0^ 25. 0.52 4 Mg 5.6 0.461 Cl 7,550. 212.98 Na 3,350. 145.725 F 1.5 0.07 K 110. 2.813 B 16. NH,(N) ^28. 1.999 TOTALS 190.918 213.846 *Total alkalinity as HCO -. C-372 1 1 Oil, gas, and coal i 2 | Plafker (1971, p. 87-88) evaluated the oil and gas resources of | 3 ;the Tertiary section in the Lituya province and concluded "The 4 -petroleum potential of the Tertiary sequence within Glacier Bay 5- National Monument is poor within the area of outcrop on land.... i U- 3 The offshore petroleum possibilities within the Monument cannot yet 7 be adequately evaluated, but there is no reason to believe that they s will differ significantly from those landward." Increased offshore 9 exploration activity has occurred since 1966, but Plafker (oral 10- communication, 1977) considers the above statement still valid. The 11 rest of the monument does not contain rocks considered to be likely I 12 source or reservoir beds (Miller and others, 1959) although many of <3 the Silurian limestones in the Chilkat province are noticeably fetid. 14 The petroleum resources of the remainder of the monument are probably 15- nil. 16 Plafker (1971, p. 89) also evaluated the coal resources of the 17 Tertiary section in the Lituya province and concluded "The coal in the '3 Lituya district has little or no commercial potential because of its 9 low rank and its occurrence of thin discontinuous beds and stringers." :: The remainder of the monument has no reported occurrence of coal, 21 (Barnes, 1967), there are no rocks likely to contain coal, and the 22 coal resources are probably nil. C-373 9.1267 Nuclear fuels \ There has been no production of uranium or thorium from Glacier , Bay National Monument nor are there any significant prospects for i future production. The nearest known radioactive occurrence lies well ii outside the eastern boundary of the monument north of William Henry Bay (Lathram and others, 1959). As discussed in the geochemistry section of Chapter B geochemical sampling of the study area for uranium and thorium was not exhaustive but the values indicate little more than locally high background of those elements throughout the 10- rocks of the area. ! The major productive uranium and thorium deposits of the world occur in i 12 peneconcordant deposits in sandstone lenses interbedded with mudstones, 13 for example, in Precambrian quartz-pebble conglomerates and(or) the occur in the study area. Major resources also occur in uraniferous 16 phosphatic rocks and black shales; both are lacking in the study area. Minor amounts of uranium have been produced from carbonates, vein deposits and uraniferous igneous rocks; the geology of the study area is favorable for these types of deposits and the Tertiary granitic stocks are of particular interest although there is no geochemical or occurrence data that suggests the presences^ o ,posC\S« ; It is unlikely that the monument contains significant uranium or i thorium resources. ' C-374 9-1257 Industrial minerals 1 i No industrial minerals are known to have ever been mined from j Glacier Bay National Monument. It has never produced abrasives, baritei, 4 I clays, evaporites and brines, kyanite, phosphates, silica sand, or Ij ii 5_ ; zeolites nor does the geology indicate any likelihood of their 6 ; presence in economic amounts. Feldspar and mica are present in 7 : enormous quantity as rock-forming minerals but the area lacks the a i kinds of pegmatites with which economic concentrations of these 9 i commodities are associated. There are large areas of marble (Burchard, i io_ i 1920); however, there is no local market for the stone. Sand and n ! gravel are present in large quantity in the area, but there is no i 12 | market for this commodity in this remote area. Similarly, dimension i 1.3 i stone or crushed rock is present in almost unlimited quantity but no u market exists. 15 > 16 ; C-375 9-1267 Chapter D Evaluation of Mineral Resources Introduction Glacier Bay National Monument is a highly mineralized area that I 5 Contains significant identified and undiscovered resources of nickel, ji Icopper, molybdenum/ zinc, silver, tungsten, and gold. i [ This evaluation of the mineral resources of the Glacier Bay National ! Monument| wilderness study area consists of a geologic introduction, a i ^description of the identified resources, a description of the favorable 10 'areas and their hypothetical and speculative resources, a discussion of geochemical and geophysical anomalies, and comments on energy resources and industrial minerals. 13 The terms used here to describe reserves and resources are those in joint use by the U.S. Bureau of Mines and the U.S. Geological Survey 15 (1976); the classification and definitions are given in figure D-l. 16 Figure D-l near here. The information on identified resources given in this chapter was prepared by the U.S. Bureau of Mines. The information on hypothetical and speculative resources and on other topics was prepared by the U.S. Geological Survey, but is based in part on information provided by the 22 Bureau of Mines. D-l TOTAL HCBOUICC* Indicated. Reserves or resources for which tonnage and grade MMNTirito UMIMlCOVfMO are computed partly from specific measurements, samples, or production data and partly from projection for a reasonable O.^.*.. IMCUtATIVt HvrOTHITICAi ^ IM MMM 1 there is specific geologic evidence of their presence. Estimates - 1 of inferred reserves or resources should include a statement kui «« > .1 «.«>»«lt MturWKl I of the specific limits within which the inferred material may lie. GLOSSARY OF RESOURCE TERMS Identified-Subeconomic. Resources that are not Reserves, but Resource. A concentration of naturally occurring solid, liquid, may become no as a result of changes in economic and legal .._ or gaseous materials in or on the Earth's.cruatjnjiuch. form conditions. that economic extraction of a commodity is currently or Para marginal. The portion of Subeconomic Resources that (1) potentially feasible. borders on being economically producible or (2) is not com Identified resources. Specific bodies of mineral-bearing material mercially available solely because of legal or political whose location, quality, and quantity are known from geo circumstances. logic evidence supported by engineering measurements with Submarginal. The portion of Subeconomic Resources which respect to the demonstrated category. would require a substantially higher price (more than 1.5 Undiscovered resources. Unspecified bodies of mineral-bearing times the price at the time of determination) or a major cost- material surmised to exist on the basis of broad geologic reducing advance in technology. knowledge and theory. Hypothetical resources. Undiscovered resources that may rea Reserve. That portion of the identified resource from which a sonably be expected to exist in a known mining district under usable mineral and energy commodity can be economically known geologic conditions. Exploration that confirms their and legally extracted at the time of determination. The term existence and reveals quantity and quality will permit their ore is used for reserves of some minerals. reclassificntion as a Reserve or Identified-Subeconomic The following definitions for measured, indicated, and inferred resource. are applicable to both the Reserve and Identified-Subeconomic Speculative resources. Undisovered resources that may occur resource com]x>nents. either in known types of deposits in a favorable geologic setting where no discoveries have been made, or in as yet Measured. Reserves or resources for which tonnage is computed unknown types of deposits that remain to be recognized. from dimensions revealed in outcrops, trenches, workings, and Exploration that confirms their existence and reveals quan drill holes and for which the grade is computed from the tity and quality will permit their reclassification as Reserves results of detailed sampling. The sites for inspection, sam or Identified-Subeconomic resources. pling, and measurement are spaced so closely and the geologic character is so well defined that size, shape, and mineral con tent are well established. The computed tonnage and grade are judged to be accurate within limits which are stated, and no such limit is judged to be different from the computed tonnage or grade by more than 20 percent. Figure D-l. Classification of mineral resources and glossary of mineral resource terms used by the U.S. Bureau of Mines and U.S. Geological Survey (1976). 9-1267 As an aid to those concerned with the economic aspects of the 2 I mineral resources, the monetary value of some of the better-known I 3 !mineral deposits is quantified as "gross-in-place-metal value." This value is obtained by multiplying the estimated tonnage of the resource all"of present by the combined dollar value per ton at February 1978 prices of/ the elements of economic interest present in the deposit. The resulting ;value is not a measure of the net worth of the deposit but it does | i i {provide both a measure of the significance of deposits and a way of ! I'comparing deposits containing different commodities. We have also used!i i this monetary value in describing some of the undiscovered resources. i Measurements in this chapter are given in both metric and English ! 1 ! 12 units and some discrepancies are apparent between the two. This is 13 because the original measurements by the Bureau of Mines were in English units; those were rounded for calculation and descriptive ; 15_ purposes; and the rounded units were then converted to metric units. | i 1 1(b It is therefore generally not possible to calculate the metric tonnages ; given using the metric dimensions given; those tonnages are rounded conversions of the English tonnages. The Bureau of Mines calculation information for identified resources is given in Chapter C. ; 25 D-3 I The monument is divided into five geologic provinces based on 'lithologic and structural features (fig. A-2). The geology is extremely ;varied. The Lituya province is characterized by Tertiary marine and minor non-marine strata resting unconformably on Mesozoic granitic | _ iintrusives and on Mesozoic country rock consisting of greenstone/ slate [ ;and phyllite, melange, graywacke and argillite. The boundary with the Fairweather province to the east is the Fairweather fault, an important !active tectonic feature that.has persisted since Tertiary time. , The Fairweather province is characterized by regionally extensive ;hornblende schist and gneiss and biotite gneiss, schist, and semischist I ! i; units of unknown age that are intruded by layered gabbro complexes also i i |of unknown age. The boundary with the Geikie province to the east is a ' tectonic suture zone of post-Permian (?) - pre-middle-Cretaceous age ! which has been the site of faulting and fracturing probably extending - into the Tertiary and which is straddled by a broad poorly defined belt |of Tertiary granitic intrusives. The Geikie province and the lithologically similar Muir province to the northeast are characterized by elongate bodies of foliated Cretaceous granitic rock and lesser amounts of unfoliated Tertiary granitic rock. ._ .Both types of granitic rocks have intruded and metamorphosed Paleozoic marine clastic, carbonate and minor volcanic rocks. The two provinces are separated on the basis of contrasting structural grain. D-4 9-1267 The Chilkat province consists of lower and middle Paleozoic 2 igraywacke, argillite, carbonate, and locally abundant volcanic rocks i 3 that are sparsely intruded by granitic rocks of Cretaceous age. An 4 important east-west fault zone occurs in the northern part of the | 5 province and a northwest-striking fault zone extends northwestward i : ;across the whole Chilkat province into the Geikie province. i ' 7 ' This complex regional geologic framework includes a variety of i a potential ore environments and magmatic-segregation, porphyry-molybdenum, i 9 porphyry-copper, vein-gold, base-metal skarn, volcanogenic-base-metal, i i i 10 :and beach-placer deposits are known in the monument. The appropriate i , n 'environment for polymetallic hydrothermal deposits in and close to 12 :intrusives is also present, but significant deposits of these types are 13 hot known. ' ! ' 1.1 ! The following discussions are ordered by geologic province, 15 beginning at the west. They are keyed to the location map in chapter i6 A (fig. A-l) and are summarized synoptically in table A-l. D-5 9-1267 r I Identified resources i i I i i Lituya province ! ' Pacific beach placer deposits ; ! i j | ! The Pacific Ocean beaches north and south of Lituya Bay (fig. A-l) 1 i contain beach placer deposits of ilmenite and gold with reported platinum I j The source of the gold is thought to be the Yakataga Formation and the i i , ilmenite and platinum are likely from the rocks of the Fairweather Range. The placers on the exposed active beaches are ephemeral and subject to l destruction, transport, and redeposition by severe storms; those on less exposed beaches and on the vegetation-covered back beaches are j ! relatively stable. The deposits have been known since the early 1800's ; i ' i 12 and have been prospected and worked intermittently since then. 13 16 D-6 1 I Resources were calculated for 12 blocks of ground using the method 2 pf sections with the grade between sections computed by the rule of iI 3 gradual changes. The calculations show that there are about 4.6 million i 4 -cubic meters (6 million cubic yards) of inferred resource with an averaga 5_ value of 1.0 percent ilmenite with a value of about $1.11 per cubic meter ;($0.85 per cubic yard), assuming $55 per ton for ilmenite. Average ; gold values were less than $0.01 per cubic meter ($0.01 per cubic yard), z assuming $150 per ounce for gold. Within the blocks of inferred o resources there are two areas that are significantly higher than the io_ average overall grade (1 and 2 on fig. A-l). A block at Boussole Bay ii n contains about 153,000 cubic meters (200,000 cubic yards) of material ,: 'averaging 3.4 percent ilmenite.. This material has i O-- u an average value of $3.83 per cubic meter ($2.92 per cubic yard). u Within a larger block south of the mouth of Echo Creek there are about i r_. 102,000 cubic meters (134,000 cubic yards) of material containing 4.2 3 percent ilmenite worth $4.94 per cubic meter ($3.77 per cubic yard) and '7 an additional $0.28 per cubic meter ($0.21 per cubic yard) in gold. D-7 9-1267 Fairweather province Brady Glacier nickel-copper deposit The Brady Glacier nickel-copper deposit is located at the | i 'easternmost exposure of the Crillon - La Perouse layered gabbro complex ! !of unknown age in the Fairweather Range (3 on fig. A-l). The deposit ! I ! ;consists of magmatically segregated nickel and copper sulfides and j i associated secondary sulfide mineralization according to Geological i I : Survey studies. Pentlandite, chalcopyrite , and violarite i j are the common ore minerals. They occur as disseminated grains, j i i interconnected grain-veinlet networks, veins, and minor lenticular j masses in zones as much as about 200 m (650 feet) thick in interlayered i i : peridotite (olivine cumulate), harzburgite (olivine-orthopyroxene- ! j 13 plagioclase cumulate), and olivine gabbro (olivine-plagioclase cumulate ! mostly i 14 and olivine-plagioclase-clinopyroxene cumulate). These/ultramafic host rocks apparently grade into or interfinger with the dominant mafic gabbro, norite, and gabbronorite that comprise the complex and are in shallow-north-dipping intrusive contact with underlying garnet-biotite schist of unknown age. Secondary mineralization has extended the deposit into the underlying country rock. The mineralization controls are thought to be: 1) the significant thickness (at least 680 m (2,200 feet) of interlayered ultramafic and minor mafic igneous rock, and 2) the apparently unsheared relationship of this probable basal ultramafic zone to the main Crillon - La Perouse complex and to its country rock. D-8 The deposit was discovered in 1958. Eighty-two diamond drill holes in and around the largely glacier-covered deposit have established that it contains at least 80 million metric tons (90 million tons) of indicated resource that averages 0.53 percent nickel, 0.33 percent copper, and contains an unspecified amount of platinum-group metals (PGM). The dimensions and descriptive details of the deposit have not been released by the owners. The estimated gross in-place metal value of this resource is about $2.5 billion at February 1978 prices, not including any value for PGM. The deposit may be economic at the present time. An additional 80 million metric tons (90 million tons) of inferred resource of the same grade are considered to be present in the deposit because exploration is incomplete and the limits of the mineralization are not known. Radar ice thickness measurements suggest the deposit could be limited at a distance of 1.6 to 3 km (1 to 2 miles) to the north by glacier ice extending below the known base of the deposit. D-9 Geikie province Margerie Glacier copper deposit The Margerie Glacier copper deposit is located near the International Boundary west of Tarr Inlet (4 on fig. A-l). It is interpreted to be a porphyry-copper deposit and contains mainly copper 3 ,with subordinate gold, silver, and tungsten. Sulfide-bearing quartz veins and disseminated sulfides occur in locally altered porphyritic Tertiary quartz monzodiorite or granodiorite cut by abundant granitic dikes. o The country rocks are hornfelsed argillite, phyllite, and slate of Permian(?) age. Chalcopyrite, pyrrhotite, and pyrite are the common M ;disseminated sulfides in the granitic rock and scheelite is also present Chalcopyrite, arsenopyrite, sphalerite, pyrite, pyrrhotite, scheelite, i ., 'and molybdenite have been identified in the quartz veins. The deposit was discovered in 1960 but has not been thoroughly delineated. D-10 The Bureau of Mines estimates the zone of disseminated sulfides containing copper, tungsten, silver, and gold mineralization is at least about 300 m (900 feet) wide horizontally, extends for 600 m in length m (2,000 feet)/and is inferred to be 300/(1*000 feet) deep. The depth is indicated by disseminated mineralization throughout at least that much change in elevation. The body as calculated for resource purposes has the shape of a prism with two sloping sides. If a tonnage factor of 0,36 cubic meters per metric ton (11,5 cubic feet per ton) is assumed, there are about 145 million metric tons (160 million tons) of inferred resource within the volume described above. The estimated average grade of the disseminated mineralization, based on 19 spaced- chip samples ranging in length from about 1 m to 30 m (3 to 100 feet) and ranging in value from 150 ppm copper to 4,400 ppm copper, is 0,2 percent copper, 0,27 grams per metric ton (0,008 ounces per ton) gold, 4,5 grams per metric ton (0,13 ounces per ton) silver, and 0,01 percent about tungsten. This is a combined<-metal value of/$5,51 per metric ton ($5 per ton), The most significant sulfide-bearing quartz vein was traced through Antermitttnt outcrops across scree slopes for about 200 m (700 feet). ^ The richest part of the vein contained 11 percent copper, 3.5 ppm gold, 100 ppm silver and 0.1 percent zinc, over a .2-m (0.65-foot) width. Other veins have somewhat higher values for lengths of as much as 20 m (70 feet) but apparently do not persist. The grade of the veins would raise the overall value of the deposit as a whole but the percentage of veins relative to disseminated mineralization is not known. D-ll The disseminated portion of this deposit has an estimated gross in- place metal value of about $800 million. Orange Point zinc-copper deposit The Orange Point zinc-copper deposit is located on the north side of Johns Hopkins Inlet about A km (2.5 miles) from its mouth (5 on fig. A-l). It consists of massive and disseminated pyrite, pyrrhotite, chalcopyrite, and sphalerite in metavolcanic rocks of probable andesitic composition. It is interpreted to be a volcanogenic sulfide deposit. The metavolcanics form a significant part of a complicated sequence of phyllite, slate, conglomerate, marble, greenstone, and greenschist of Permian(?) age. Specific mineralization controls are not clear, except for the restriction of the sulfides to the metavolcanic rocks. Orange Point is an informal name given to a prominent shoreline point because of the very conspicuous staining. The north side of Johns Hopkins Inlet has numerous stained zones which were first examined in the 1930 f s and have been re-examined at least twice since then. The deposit, as presently known, was not recognized until 1977. For the purpose of resource calculations the main mineralized zone of the Orange Point deposit is inferred to be roughly the shape of a rectangular prism with a strike length of about 120 m (400 feet), a depth of about 90 m (300 feet), and an average width of about 20 m (65 feet). Using a tonnage factor of 0,30 cubic meters per metric ton (9.5 cubic feet per ton), the mineralized zone contains 720,000 metric tons (800,000 tons) of inferred resource, D-12 9-1267 1 ' The main mineralized zone was sampled at four locations: across i 2 'the southern end of the zone; across the northern end of the zone; on i i i 3 ;the top of the zone near its south end; and on the top of the zone about; 4 '20 m (60 feet) further north. The sample lines on top of the zone 5_ jcrossed only part of the mineralized body. These sample lines show that 6 'there are portions of the zone from about 5 to 8 m (15 to 25 feet) wide , 7 that average eight times more copper and zinc than most of the remainder. i ! 3 .There are insufficient data to establish the shape or extent of these 9 high-grade sections within the larger zone, but they are probably i ; ic_ jelongate lenses and may represent about one-third of the whole zone, or H 'about 250,000 metric tons (270,000 tons) of inferred resource. Values 12 'for individual 1.5 m- (5.0 foot-) long samples of the high-grade portions n ;range up to 5.2 percent copper, 19 percent zinc, 3.4 grams per metric u : ton (0.1 ounces per ton) gold, and 69 grams per metric ton (2.0 ounces is ! per ton) silver. The estimated average grade for the higher grade 13 ^ections is 2.7 percent copper, 5.2 percent zinc, 1.0 grams per metric 17 ton (0.03 ounces per ton) gold, and 34 grams per metric ton (1.0 ounce '3 per ton) silver. This amounts to a combined-metal value of about $83 per metric ton ($75 per ton) at February 1978 prices. The lower grade :c- remainder of the mineralized zone, about 470,000 metric tons (530,000 21 tons) of inferred resource, has an estimated average grade of 0,4 percent 2: copper, 0.3 percent zinc, 0.2 grams per metric ton (0.006 ounces per ton) 23 gold, and 12 grams per metric ton (0,35 ounces per ton) silver. This amounts to a combined-metal value of about $10 per metric ton ($9 per :s ton) at February 1978 prices. D-13 ''~ ~~- - " This deposit, as now known, has a gross in-place metal value of about $20 to $25 million. The higher grade portions of it may be exploitable by an efficient small-scale operation. The value would be much larger if the main mineralization is found to extend to depth and under cover to the north. Massive chalcopyrite deposit The area west of the Rendu Glacier (6 on fig. A-l) contains newly discovered copper-gold-silver-tungsten skarn deposits in discontinuous Devonian or Silurian carbonates adjacent to Cretaceous, or possibly younger, granitic rocks. Limited sampling suggests that chalcopyrite, scheelite and sphalerite are the most common ore minerals. The area is somewhat inaccessible and the outcrops were first visited and named by the U.S. Bureau of Mines in 1976. A 3.7 m by 3.7 m (12 x 12 foot) cliff face section of the deposit was accessible for sampling and examination. The extent of the zone the zone could not be determined accurately, but/is estimated to continue downward at least 2 A m (80 feet) and 12 m (AO feet) into the rock face. Using a 0.28 cubic meter per metric ton (9.0 cubic feet per ton) density factor, this volume contains 3,800 metric tons (4,300 tons) of inferred resource. The average grade of the two samples taken across the zone is 0.5 percent tungsten, 5 per cent copper, 2AO grams per metric ton (7 ounces per ton) silver, 5.2 grams per metric ton (0.15 ounces per ton) gold, for a combined-metal value of $215 per ton at February 1978 prices. The gross in-place combined metal value of this deposit is about $900,000. D-1A 9-1267 1 ! Reid Inlet gold deposits 1 2 i The Reid Inlet area in the upper part of Glacier Bay proper (7 on ! j f 3 fig. A-l) contains abundant narrow, discontinuous gold veins. The veins | i 4 jare commonly banded and contain arsenopyrite, pyrite, galena, sphalerite, |i i ___ ichalcopyrite, and gold. The sulfide mineralization also extends into ' 6 'adjacent wall rock, which consists largely of altered well-foliated granodiorite and quartz diorite of Cretaceous age. Some large inclusions i j 3 ;of hornfels, schist, and slate in the granitic rock are also locally 9 imineralized. Dikes and sills of fine-grained mafic rock are locally 10_ jabundant. The quartz veins generally strike about N. 30° E. and dip j i i n Jmoderately northwest. The veins appear to be localized in shear zones , i j 12 jthat probably resulted from tectonic movement along the Tarr Inlet ; : I 13 -suture zone in Tertiary time. ! u ' This district was first discovered in the early 1920's. The total ,,__ 'value of the gold produced from the district when it was active between ' j :1938 and 1970 was about $250,000. In terms of $150 per ounce gold, the 16 , I ; 17 lvalue of this production is about $1 million. The narrow and discontinuous nature of the gold veins makes estimation of the resources of the district difficult. D-15 9-1267 Alaska Chief copper deposit ! i The Alaska Chief copper-silver-gold-zinc deposit is located on the ' i i Iwest side of Glacier Bay proper near its mouth (8 on fig. A-l). It is ; j ia skarn-type deposit containing pyrite, pyrrhotite, chalcopyrite/ ; ! ! I sphalerite, bornite, malachite, and azurite. The sulfides occur in i ; ijcalcite gangue in tactite/ hornfels, and marble near a granitic body of ' I Tertiary age. The country rocks are of Devonian- or Silurian age. The , | I mineralization is apparently controlled by the carbonate layers. The deposit was discovered in 1906 and patented in 1924. j 10 i According to MacKevett and others (1971), the deposit is exposed [ lover an area about 46 m (150 feet) by 9 m (30 feet) and is estimated to I i i ijextend to 18 m (60 feet) depth. Limited surface sampling indicates a i jgrade of about 1.0 percent copper, 3.4 grams per metric ton (0.1 ounce i ** ' Iper ton) gold, and 69 grams per metric ton (2 ounces per ton) silver. i jusing a conversion factor of 0.31 cubic meter per metric ton (10 cubic jfeet per ton), this amounts to 24,000 metric tons (27,000 tons) of i jindicated resources. A Bureau of Mines party visited the prospect ibriefly in 1975 and concurs with this estimate. The gross-in-place- metal value is about $1 million. 2-t D-16 9-1267 Muir province The Nunatak molybdenum deposit The Muir Inlet Nunatak molybdenum deposit is located on the east side of upper Muir Inlet (9 on fig. A-l). It is a porphyry-molybdenum 5_ !deposit in an isolated hill which was a nunatak in the 1930's. It 6 consists primarily of molybdenite, pyrrhotite, chalcopyrite, and pyrite, 7 |with minor tetrahedrite, bornite, and enargite in a complicated deposit s 3 jthat includes mineralized 1) quartz-vein stockwork, 2) fault zone, and i 9 I 3) porphyritic dikes, as well as portions in which the sulfides are I ]0_ |disseminated. The deposit is important for its molybdenum content and 1 n jit contains very little copper. Host rocks are 12 Ihornfels and calc-silicate hornfels derived from layered sedimentary i 13 ;rocks of Early to Middle Paleozoic age that were metamorphosed in mid- I 4 Cretaceous time. The mineralization and associated alteration are 'probably related to the porphyritic granitic dikes, ;They are not dated isotopically but are considered to be related to ,, !nearby granitic plutons of inferred mid-Tertiary age. : The essential features of the deposit include -9 porphyritic granitic dikes, quartz vein stockwork, and silicic -.__ alteration; all in a relatively highly fractured fine-grained hornfels. The deposit is not fully explored,and its boundaries are not completely i ' 22 iknown to the northwest, northeast, and downwards. The deposit was discovered in 1941. D-17 9-1267 For the purpose of resource calculations the Nunatak deposit has been divided into three areas: 1) stockwork with conspicuous molybdenite I as defined by the limit of 1942 Bureau of Mines channel samples (Sanford and others, 1949); 2) stockwork with inconspicuous molybdenite as 5 defined by Twenhofel (1946) and MacKevett and others (1971) mapping; i i 3) mineralized zones exposed in the Muir #1 and #2 and AMEX #2 diamond i idrill holes and on the surface in the area of the Nunatak Fault. All i !resource calculations are based on a 0.36 cubic meter per metric ton i j I (11.5 cubic feet per ton) density factor. The resource estimate and its i i i basis is given for each area below. i I 1. Stockwork with conspicuous molybdenite: This block extends from ! I !sea level to an elevation of 360 feet and over a 270-m (875-feet) long ! i iby 190 m (600 feet) wide surface area. It contains 7.4 million metric i i jtons (8.2 million tons) of indicated resource above sea level and 8.3 j , i imillion metric tons (9.1 million tons) of inferred resource from sea , level to 60 m (200 feet) below sea level. Based on 430 m (1,440 feet) ! i i j of channel sampling, four diamond drill holes and geochemical sampling, i ' the average grade is estimated to be 0.06 percent molybdenum and 0.02 percent copper. D-18 9-1267 1 I 2. Stockwork with inconspicuous molybdenite: This block ranges in ; i 2 'elevation from 300 to 1,150 feet and covers an area to 335 m (1,100 J j ' 3 feet) wide and about 980 m (3 f 200 feet) long. Based on five sections : i 4 'along the long axis of the area, there are 124 million metric tons (137 j i 5~ ^million tons) of indicated resource. Of this, 18 million metric tons i (20 million tons) are located below sea level. This resource is r accessible to open pit mining; calculations show that a pit with 3 60-degree walls and extending to 200 feet below sea level would involve ' the excavation of 47 million metric tons (52 million tons) of waste rock. | j 10 of this, 3.6 million metric tons (4 million tons) would be from below i i 11 |sea level. Based on five diamond drill holes and geochemical sampling, ' 2 ,the estimated grade is 0.04 percent molybdenum and 0.02 percent copper. 13 3. Mineralized zones exposed in Muir #1 and #2 and AMEX #2 diamond 14 'drill holes and on the surface in the area of the Nunatak fault: These 15~ .diamond drill holes intersect a highly mineralized halo around the i , 16 jstockwork that is up to about 50 m (160 feet) wide that may extend as a i ', 17 cap for hundreds of meters (thousands of feet) . It is not well enough 3 known to calculate tonnage or grade. This block could, with further exploration, prove to contain the highest grade resource in the deposit. "°- Drill hole intercepts of the halo range in grade from 0.11 to 0.14 -' percent molybdenum. The resource of this area is included in the 22 calculation for area number 2 above. D-19 In summary, this deposit contains 132 million metric tons (145 million tons) of indicated resource containing from 0.04 to 0.06 percent molybdenum and 0.02 percent copper accessible to surface mining, and an additional 8.3 million metric tons (9.1 million tons) of inferred resource containing 0.06 percent molybdenum and 0.02 percent copper below sea level. Within the volume accessible to surface mining is a potentially important higher grade section that, if taken by itself, would have to be mined from underground. The gross in-place metal value of the deposit, as it is now known, is about $550 million. Hypothetical and speculative resources Introduction The estimation of hypothetical and speculative resources is inherently a subjective process. The process, as used here, integrates and synthesizes the regional geology, the information on the identified resources, geochemistry, geophysics, exploration and production history, accessibility, surficial cover, and to some extent the economic factors involved in exploration, mine development, and mining. Estimation of undiscovered resources in any given area requires recognition of the ore environments which define a favorable area and definition of deposit-type, -size, and -grade model(s) appropriate to those environment(s). D-20 9-1267 I Two kinds of deposit models are used: 1) if an actual known j deposit in the area is close to the minimum tonnage and grade considered j likely to attract serious development interest, then it is used as the j I I 4 I model for that area; 2) otherwise, a conceptual deposit model meeting ; 5 ii those minimum standards is used. i 5 i The boundaries of favorable areas are essentially the limits of ', \ i irecognized ore environments and are defined primarily by geology as it j I they i a irelates to a specific deposit model, but/ are also influenced by the size 3 I! 1 and significance of the known deposits, geochemistry, geophysics, and ' i < !history of previous exploration. The favorable areas and the ' 1C ! I i I n isignificant known deposits in Glacier Bay National Monument are listed , I i 12 !j in table A-l and shown on figure A-l. !j 13 j The next step in the resource estimation process is to apply the | ]" iI deposit model to the favorable area and to estimate the maximum number ! ; of deposits that are geologically permissible within the area.' This ! involves admittedly subjective application of the knowledge of the ', i !apparent controls of mineralization, and of the geology, geophysics, jand| geochemistry of the area. The result of this step can be either ! a single number or a range of numbers, depending on the case at hand. IC i The next step is also subjective; it estimates the likelihood of : the actual occurrence and discovery of some or all of the deposits that, 2i i I are geologically permissible. This involves use of all the information available about the area as well as the knowledge, judgment, and 23 !experience of those making the estimate. The result is an estimate of 1 the chance that the maximum permissble (or a lesser) number actually ;are in the area and are discoverable. _____ .__._ __ _.___ | Singer (1978) considers the factors in these two steps in regard ito regional resource assessment practice, and states, "...exact rules ! whereby estimates were constructed cannot be precisely stated." i i Just as the identified resources underlie only a small part (estimated here at less than 0.1 percent) of the total area of the monument, any resources present and discovered in these favorable areas would underlie a small area. In other words, even though the areas favorable for certain types of deposits are large, the resources that actually exist there are concentrated in a few small areas. The favor able areas with hypothetical resources underline about 8 percent of the i nonument and those with speculative resources about 13 percent. ' The goal of this process is to communicate to those who have the authority and responsibility for making decisions that affect the availability of those mineral resources all the information in the minds of those who know most about the mineral resources of a given area. The process is admittedly imprecise and imperfect, but communication of i the results does provide more and, we believe, better information than would otherwise be available. 22 D-22 9-1267 i Lituya province | i Pacific beach placer favorable area i 3 I The ocean beaches along the Pacific Coast from Boussole Bay on the i 4 south to the northern boundary of the monument near Sea Otter Creek 5_ |(A on fig. A-l) contain beach placer deposits of ilmenite and gold with i 4 lesser amounts of platinum and magnetite. Almost all stretches of beach 7 ,contain some values; but, as described in the section on identified s iresources, the higher values are localized in two localities. Identified 9 :resources were calculated for twelve separate blocks on the beaches. 10_ Only one block was inferred to extend below about 2 m (6 feet), the i i, | average sampling depth. i All of the beach areas below and between the resource-calculation 13 ! blocks are considered favorable for beach placer deposits; thus about IJ 2,100 hectares (8 square miles) are considered to contain hypothetical ,.ij Ij resources. i, i Calculations by the U.S. Bureau of Mines indicate that about 4.6 ; '7 i million cubic meters (6 million cubic yards) of hypothetical resource containing about 1.0 percent ilmenite worth about $1.11 per cubic meter ($0.85 per cubic yard) occur beneath the blocks with identified ! resources. These blocks comprise about 260 hectares (1 square mile) of the favorable area. The other 1,810 hectares (7 square miles) of I beach deposits are estimated on the same basis by the Bureau of Mines ] to contain about 64 million cubic meters (84 million cubic yards) of hypothetical resource containing about the same grade material. D-23 This totals about 70 million cubic meters (90 million cubic yards) of hypothetical resource. ii 3 ; i 4 { Fairweather province i 5- ! Crillon - La Perouse favorable area 5 The Crillon - La Perouse layered gabbro complex contains the Brady 7 Glacier magmatic segregation nickel-copper deposit. The whole 24,600 3 hectare (95 square miles) area of the complex (B on fig. A-l) is 9 ;considered favorable for the occurrence of magmatic segregation nickel- o 'copper deposits on the basis of the Brady Glacier deposit, favorable 11 |geology, and the occurrence of several small local shear zone deposits i 12 !along the western and northern exposed contacts of the complex. These i 13 small deposits suggest secondary mineralization derived from larger 14 iconcealed magmatic segregation deposits. '-- ' There has been little exploration in this favorable area to date. ii jProspecting and exploration will be extremely difficult and expensive i ' 7 because of rugged terrain, limited exposures, and inaccessibility. The ^ southern, eastern, and northeastern contacts of the complex are almost ^ wholly ice-covered. 22 D-24 9-1267 In estimating resources In the favorable area, we assume that, considering the remoteness and difficulty of the terrane, no deposit 3 I smaller than about the size of the Brady Glacier deposit indicated 4 resource (80 million metric tons (90 million tons) of 0.53 percent nickeil i i I ! 5-|and 0.33 percent copper) is likely to attract serious exploration and ; ; I 6 jdevelopment attention. We therefore ignore the potential for smaller ;' 7 .deposits as well as the potential for concealed deposits. It is i | s possible that large ultramafic masses are concealed under the many : ii i; 9 .glaciers crossing the western and northern contact of the complex, under! i ! 10- |the upper reaches of the Brady Glacier Icefield north of the Brady ' | i T Glacier deposit, or at-depth within the gabbro complex; but their | | 12 |discovery and exploration and the discovery of any associated deposits '. | ! 13 ;would be difficult and expensive. I 15 22 D-25 9-1267 The Brady Glacier deposit model as presently understood requires : that a significant thickness of interlayered ultramafic and minor mafic ; I intrusive rocks of the basal zone of the complex be present. Applying ' i this criterion to the estimation of undiscovered resources in the 4 | : ifavorable area involves several lines of reasoning: 1) except at the 5 i ; iBrady Glacier deposit, there are no significant thicknesses of exposed I : iultramafic rock known within the boundaries of the complex; geologic i ' 8 !reasoning suggests that only the basal part of the complex is likely 9 [to have such rocks; the exposed periphery of the complex is therefore jof greatest interest; 2) all exposures of the contact are steep and '' i i n {accessible exposures show evidence of high-temperature shearing probably j t 12 ! associated with movement of the complex during or shortly after its ; emplacement; no shallow-dipping contacts like those at the Brady Glacier lare known to exist elsewhere; 3) analysis of the asymmetrical layering !in the complex suggests that the western part is thicker than the eastern and the basal zone is more likely to be concealed at depth 16 , , there; and 4) no large thicknesses of ultramafic rock are known on the ^visible and(or) accessible exposures of the contact and no unusual accumulations of ultramafic morainal debris which could have come from near either exposed or concealed contacts are known to exist, although this latter point has not been investigated systematically. D-26 9-1267 1 i Applying the geologic model of the Brady Glacier deposit to the i 2 |rest of the complex and considering only the exposed parts/ which are j 3 I mostly along the western and northern contacts, we consider that (in ( i 4 jspite of the negative evidence just presented) it is geologically i i , 5_ jpermissible for there to be as many as two more discoverable deposits of 6 ,the Brady Glacier type and size somewhere along the exposed contact. This is because less than 5 percent of the exposed contact has been s ivisited and therefore the rocks present are not known. Based on the 9 available information about the contact and the apparent absence of i , 0_ significant volumes of peridotite along it we suggest that there is a i, 11 in 3 chance of there actually being one other discoverable deposit. j 12 1 This is considered here as 82 million metric tons (90 million i , 3 tons) of hypothetical resource. 14 . The Crillon - La Perouse complex also contains unevaluated , 5_ resources of iron, titanium, cobalt, platinum group metals, and , 6 chromium, but based on present information, those resources are , 7 overshadowed by the nickel-copper resources. D-27 9-1267 Mount Fairweather favorable area A large layered gabbro complex at Mount Fairweather sheds a significant amount of mineralized rock onto the Fairweather, Sea Otter, and informally named Two Fish glaciers in the northwestern part of the monument (C on fig. A-l). Float samples of ultramafic rock contain j i copper, nickel, chromium, cobalt, PGM (platinum group metals), iron, andj titanium. No specimens of massive sulfide or chromitite have been found i No samples of any kind have to our knowledge been collected in place. J The metallic minerals observed are all disseminated and include chromite, magnetite, ilmenite, cubanite, chalcopyrite, pyrrhotite, and pentlandite. j The 2,350 hectare ( 9 square miles) Mount Fairweather complex is i considered similar to the Crillon - La Perouse complex and intrudes generally the same kind of rocks. Its general geologic features and j ii 15 ipotential for magmatic segregation deposits, the mineralized material on 16 ' the glaciers, and a significant aeromagnetic anomaly over the western ; I 'i i flank of the complex all suggest that the contact, particularly its i IS ;western and northern segments, is a favorable place to look for as-yet-! i ;undiscovered nickel, copper, PGM, and chromite deposits. There has been ! ,no exploration that we know of in the area. Our own investigations were severely hampered by the extremely difficult terrain, poor weather, i i i 22 and limited time. Any prospecting and exploration would be exceedingly j i, (difficult and expensive, as would mine development and operation. 24 25 D-28 9-1257 Based on the above factors, we consider it'is'geologically permissible - ^ T that the western part of the Mount Fairweather complex contains an j j exposed magmatic segregation deposit that could be as large and important as the Brady Glacier deposit. This is considered here as 80 _ T- i 5 million metric tons C90 million tons) of speculative resource, The aeromagnetic and gravity field information indicates that the , gabbros are concealed at depth in the areas between the exposed four complexes in the Fairweather Range. Although such concealed ! connections are not accessible to exploration, they do suggest that all of the complexes are parts of a single large body. Geikie province j Margerie Glacier favorable area I 13 An area extending from the International Boundary at upper Tarr : Inlet south along the west side of that inlet and across Johns Hopkins Inlet (fig. A-l) is covered by two generally overlapping favorable , areas. One area is favorable for porphyry-copper deposits and the other for volcanogenic-sulfide deposits. D-29 9-1267 An area of about 15,700 hectares (60 square miles) extending from | j Margerie Glacier south to Johns Hopkins Inlet (D on fig. A-l) is considered a favorable environment for copper porphyries on the basis of geology, geochemistry, and the "presence of the Margerie Glacier j 5 |copper deposit. This deposit, as described previously, has been ; | I iestimated' by the Bureau of Mines to contain about 145 million metric i: |tons (160 million tons) of inferred resource containing about 0.2 percent I |copper as well as gold, silver, and tungsten. Comparison of the !estimate with the Menzie, Singer, and De Young (1978) tonnage and grade 10 model for porphyry-copper deposits in western Canada and Alaska (not all of them mines) indicates that the estimate is above the 50th 12 percentile in tonnage and between the 10th and 50th percentile in grade. 13 In evaluating the resources of this area we estimate that a 14 porphyry-copper deposit must contain at least 45 million metric tons \ 15- |(50 million tons) at a grade of 0.4 percent copper in order to be a i " ; I 'candidate for mine development. We therefore ignore smaller and lower ^ 16 i j ! ! grade deposits (as well as deposits that are concealed so as to be j - ' unlikely to find with present technology) in applying this deposit model to the area. The difficulty of exploration is locally great, but ! not overwhelming; significant glacier cover is present. We believe ', there has been very little systematic prospecting. 22 D-30 9-1267 ; I I We consider it geologically permissible for this favorable area to I | contain as many as two (^opper-^orphyry-tdeposits of the above viable ; size; one of these could be the Margerie Glacier deposit. The favorable i area has not been thoroughly prospected and the details of the geology I are not known. Available information on the distribution of hornfelsed i ! rocks and of intrusives suggest to us that there is about a 1 in 2 i chance that there is one deposit of viable size actually present and i I exposed. We consider it here as 45 million metric tons (50 million | tons) of hypothetical resource. 10_ j An adjacent 6,480 hectare (25 square miles) area extending i northeastward across Tarr Inlet (E on fig. A-l and in table A-l) is i ! geologically similar to the area near Margerie Glacier and has tungsten j 13 iand molybdenum stream sediment geochemical anomalies. We consider this extension favorable for the occurrence o f /coppe f\ggrphyr yjdepo sits. i i There has been little if any prospecting in the area and the steep ; terrain and thick glacial cover at lower elevations would make I I exploration difficult. The available information does not support any I quantification of the speculative copper resources that may be present. D-31 9-1267 The metavolcanic rocks that host the Orange Point volcanogenic i i sulfide deposit occur mixed with other rock types in essentially the same area (D on fig. A-l) of about 15,700 hectares (60 square miles) between the Margerie Glacier and the south side of Johns Hopkins Inlet. 5 This area is considered favorable for the occurrence of similar deposits; because of the geologic features, geochemical anomalies, and the presence of the Orange Point deposit. Comparison of the Orange Point deposit (0.72 million metric tons (0.80 million tons) containing a weighted average of 1.2 percent copper and 1.9 percent zinc) with the Menzie, 10 Singer, and De Young (1978) model of world-wide felsic and intermediate j volcanogenic sulfide deposits suggests that the Orange Point deposit as presently known is between the 50th and 10th percentiles in tonnage | 13 I and copper and zinc grade. In this model there is a significant negative correlation of copper grade with tonnage. In estimating the hypothetical resources of this favorable area, we consider that a 0.9 million metric ton (1 million ton) deposit j averaging 1.5 percent copper and 2.0 percent zinc is the smallest likely to attract serious development interest. Orange Point could be that large and rich. We ignore the resources that would be contained in smaller deposits than our model and in concealed deposits that would not be discovered using intensive prospecting methods. 22 D-32 9-1267 1 Voleanogenic sulfide deposits may occur in clusters, some of which 2 imay be very large. Applying the above deposit model to the whole : 3 i favorable area, we consider it geologically permissible that there are * i as many as five such deposits present and that at least one deposit I s-icould contain 5 million metric tons (5 million tons) of resource. The s favorable area has not been thoroughly prospected but exposures of 7 metavolcanic rocks are limited, suggesting to us that there is a 1 in 5 s chance that there is one deposit of the minimum size described above 9 exposed in the favorable area, in addition to the Orange Point deposit. 10- This is considered 0.9 million metric tons (1 million tons) of 11 hypothetical resource containing zinc and copper. The resource could 12 be much larger. ; 13 The porphyry-copper and volcanogenic-sulfide deposit favorable 14 areas extend across to the south side of Johns Hopkins Inlet (fig. A-l). is- Further south the geology and geochemistry are relatively poorly known, 16 but it is likely that the same ore environments persist southward to J 7 where the Brady Glacier conceals the potential host rocks. Both is Tertiary and Cretaceous intrusive bodies occur in the area. D-33 9.12S7 1 We suggest that this 10,200 hectare (39 square miles) extension ;'(F on fig. A-l) is favorable for the occurrence of porphyry-copper-type 3 icopper-gold-silver-tungsten and volcanogenic-sulfide-type zinc-copper ; 4 'deposits. There has apparently been very little exploration in the area i i ;! ' iI 5 _ and prospecting would be difficult and expensive because of the 6 \ precipitous terrain and extensive glacier cover. Mine development and operation would also be difficult and expensive. The available 8 information does not support any quantification of the speculative 9 copper, zinc, and other resources that may be present in this area. 10- jj Rendu Glacier favorable area 12 A newly discovered copper-goldTsilver-tungsten skarn deposit in 13 the area west of Rendu Glacier has called attention to the resources 14 that may be present in discontinuous Paleozoic carbonates adjacent to is- Cretaceous or younger granitic rocks in that area. Limited information 16 indicates that the single known deposit (the "massive chalcopyrite deposit") contains about 3,800 metric tons (4,300 tons) of inferred resource containing an estimated 5.0 percent copper, 0.5 percent tungsten, plus some silver and gold. D-34 '. i. GOVERNMENT PRINTING OF?!C£ HT2 O 9.1267 ! At least 2,500 hectares (8 square miles) in this same area (H on j i 2 : fig. A-l) are favorable for similar deposits although the carbonate i i 3 units which are the likely hosts underlie only a small part of the | i i 4 ' favorable area. Several exposed deposits are geologically permissible . 5_ in the area; most are likely to be inaccessible and small. We suggest i. 6 that in order to attract serious exploration and development interest 7 any skarn deposit in this area would have to have a gross-in-place- s metal value of $2 million. Such a deposit could be present and we i 9 suggest the chance of such an occurrence is about 1 in 10. We consider; ! j 10- this an unquantified speculative copper-tungsten resource. j 11 The area is extremely rugged and difficult to explore and very i 12 little if any prospecting has taken place. The available high-altitude! i 13 aeromagnetic information does not appear to be helpful in identifying ; u the known skarn deposits in this and the Queen Inlet area. ; is j is Re id Inlet favorable area j i i; The Feid Inlet gold district has produced between 240 and 275 ; 13 kilograms (7,000 to 8,000 ounces) of gold from narrow discontinuous veins. The whole 10,380 hectare (40 square miles) district is - considered favorable for the occurrence of gold-bearing veins. .: Comparison of the production with the model of vein gold deposits from i 22' western Canada and Alaska, not all of them mines (Menzie, Singer, and 23 De Young, 1978),suggests that the district is not far below the 10th 2~ percentile in terms of tonnage of contained gold. D 35 : GO'- Sr.NME 9.1257 ! The favorable area (G on fig. A-l) coincides with the Reid Inlet 1 , i 1 district; we consider it geologically permissible that an amount of 2 ______._____ ._. j gold]equal to about twice the past production f(480 kilograms or 14/000 . is still present in the district. This is considered a i I ! 5 ihypothetical gold resource. This resource is in narrow, discontinuous ,veins that are difficult and expensive to explore and would be expensive to mine, as none are likely to be amenable to large-scale mining. g Alaska Chief favorable area i The Alaska Chief copper-silver-gold-zinc skarn deposit, on the west n side of Glacier Bay near its entrance, contains 24,000 metric tons ! ; | (27,000 tons) of indicated resources with an average grade 13 of 1.0 percent copper plus some gold and silver. Comparison with the [ , 4 Menzie, Singer, and De Young (1978) world-wide model for copper skarn ,._ deposits shows the Alaska Chief, as presently known, is below the 10th ! percentile in tonnage and below the 50th percentile in grade. 16 Other areas in the vicinity have similar geology and an extensive favorable area could be assumed. We feel that it is unlikely that any ; deposits of sufficient tonnage and grade to warrant serious exploration interest are present and therefore make no resource estimate. D-36 9-1267 Muir province | 2 | Muir Inlet favorable area ; ! .I 3 I; The hornfels and intrusive rocks that are host to the -_,_____. _^ i i 4 !iNunatak molybdenum deposit are widely exposed in the vicinity of upper ii 5 _ Muir Inlet. A large area is considered favorable for the occurrence of 6 porphyry-molybdenum deposits because of the geology, geochemistry, and 7 the presence of the estimated 132 million metric ton (145 million ton) 8 Nunatak deposit, which contains between 0.04 and 0.06 percent molybdenum : i 9 and 0.02 percent copper, and of the smaller nearby Bruce Hills deposit. 10 _ In comparison with the grade and tonnage model (Menzie, Singer, and 11 De Young, 1978) for known porphyry-molybdenum deposits of the world, i 12 the Nunatak deposit, as presently known, is between the 50th and the is 90th percentiles in size and just below the 10th percentile in grade. : 14 About 39,700 hectares (153 square miles) of the upper Muir Inlet is- area (I on fig. A-l) is considered favorable for the occurrence of 16 /molybdenum-^ rphyryjjtype deposits. In addition, an area of about 55,400 t i? hectares (214 square miles) to the south and southeast of the favorable is area contains high enough molybdenum geochemical values (J on fig. A-l) :o to warrant its tentative inclusion, even though the geology is somewhat -c-- different. 24 9-!257 j In evaluating the mineral resource potential of this favorable area, 2 we assume that the minimum size and grade deposit that would attract 3 serious interest would have at least 90 million metric tons (100 million 4 tons) of resources containing between 0.15 and 0.20 percent molybdenum. ,i ii 5 _ We ignore resources contained in smaller deposits, as well as those in 6 concealed deposits. The whole favorable area is relatively well 7 exposed, is relatively accessible, and has been moderately well 8 prospected. We therefore consider it unlikely that there are any 9 undiscovered deposits having extensive exposures like the Nunatak deposit, 10- Consideration of the geology, geochemistry, and the deposit model i a indicate that it is geologically permissible that as many as three i 12 porphyry-molybdenum deposits meeting the minimum size and grade to | 13 attract serious attention may be exposed in the favorable area. Although id the area has been moderately well prospected, we feel that neither the 15_ Nunatak nor Bruce Hills deposits have been explored thoroughly enough 16 to establish that they do not meet the minimum, and we suggest that i? there is a 1 in 2 chance that one of them or an as-yet-undiscovered is deposit is of that size or larger. Such a deposit is here considered 90 :-, million metric tons (100 million tons) of hypothetical resource. D-38 9.1267 Casement Glacier favorable area ! *, , i| The northernmost part of Glacier Bay National Monument is largely : 2 ' \ glacier covered (plate 1) and the geology is not well known. Few j i significant mineral deposits are known in the area (K on fig. A-l) and i 4 ! ! ! I the geochemical data are sparse. The area is largely underlain by hornfelsed Paleozoic clastic rocks, associated marbles, and Cretaceous granitic rocks. Dikes and highly fractured areas are locally abundant, although not as common as in the Muir Inlet favorable area. ' We suggest that a large area (K on fig. A-l) north and west of Muir f»o«-f>l\y»-y- Inlet is favorable for the occurrence ofImolybdenum and-copper i o AI , ii" deposits. The area has not been prospected, probably because of I its inaccessibility and glacier cover, but the terrain is not ; particularly difficult. The glaciers have been receding significantly , in this general area and new bedrock areas have been recently exposed. 14 The available data do not support the quantification of the 15 i speculative molybdenum and copper resources that may be present. 6 i i The current interpretation of the Orange Point zinc-copper deposit as a volcanogenic sulfide occurrence implies that similar syngenetic ; 5 mineral deposits may be present in correlative strata. There are two other outcrop belts of known Permian rocks in the monument and, indeed, the mixture of volcanic, carbonate, and clastic rocks in those belts is the main basis for the suggestion that the lithically similar host rocks of the Orange Point deposit are Permian in age. We suggest that both of these belts are favorable for the occurrence of volcanogenic-sulfide-type zinc-copper deposits. There has been little, if any, prospecting in the two belts. D-39 - -'-"^^- 9.^267 The northern belt (L on fig. A-l) is in the Muir province in an 2 area where geochemical data are sparse because of sampling problems and 3 glacier cover. Exploration of this belt would be hampered by the very 4 extensive glacier cover and unusual inaccessibility. The available information does not support any quantification of the speculative zinc and copper resources that may be present in this northern area. 9 Chilkat province 10 _ White Glacier favorable area n As discussed previously for the Casement Glacier favorable area, 12 known Permian rocks in the monument are considered hosts for undiscovered 13 volcanogenic sulfide deposits. The southern of the two outcrop belts of 14 known Permian rocks is in the Chilkat province (M on fig. A-l). It ^-coincides with an area of significant geochemical anomalies (figs. B-24, ;6 B-25) and includes the White Glacier copper and zinc occurrences. - Exploration would be hampered by locally precipitous topography. : . The available information does not support any quantification of the speculative resources that may be present. D-40, 9-1267 l Other areas with geochemical and(or) i geophysical anomalies 3 There are several areas in the monument which have significant 4 geochemical and(or) geophysical anomalies which have not been checked. i These anomalies may or may not indicate the presence of mineral , resources; they are noted here because they clearly warrant further i investigation. Q Four of the areas: 1) the North Arm of Dundas Bay, 2) Mount VJ g Merriam, 3) Miller Peak, and 4) Berg Mountain, were known from the 1966 10 _ studies; subsequent work has reconfirmed their significance. These four n areas were discussed fairly thoroughly in the report of 1966 studies 12 (MacKevett and others, 1971) and are parts of areas designated 7, 9, 13, 13 14, and 11, respectively, on figure B-25. Two of these areas, Dundas u Bay and Miller Peak, ^are near known mineral deposits of relatively minor 15_. significance. Because of the prior attention given these four areas, 16 we do not consider them further here. 17 Three other areas are recognized from 1975-1977 studies. They are -, near: 1) Excursion Inlet, 2) Mount Escures, and 3) Cape Spencer peninsula. They are parts of areas designated 15, 2, 4, and 8, - respectively, on figure B-25, and parts of areas 10, 1, and 3, respectively, on figure B-24. D-41 9.1287 1 The area south of Mount Escures in the Lituya province (N on fig. 2 A-l) has many bedrock and stream sediment samples with anomalous amounts 3 of cobalt, chromium, copper, nickel, zinc, and mercury. The bedrock 4 consists mostly of graywacke, limy slate, and greenstone of the 5 _ Cretaceous Yakutat Group intruded by small granitic stocks of Cretaceous 5 age. No mineral deposits are known in the area and there probably has ; been little prospecting. The terrain and access are not particularly 3 difficult and there are no glaciers. The stream sediment anomalies may 9 be related to the metal content of surficial deposits derived from the 13 _ gabbro complexes and hornblende-bearing metamorphic rocks on the east 1 side of the Fairweather fault. 2 The area from Cape Spencer north to the Crillon - La Perouse layered 3 gabbro complex (O on fig. A-l) has stream sediment and bedrock samples * with locally anomalous amounts of beryllium, chromium, cobalt, copper, i:~ nickel, zinc, mercury, and lead. The country rock, which is extensively intruded by granitic bodies of Tertiary and Tertiary or Cretaceous age and by gabbroic bodies of unknown age, consists largely of biotite ? schist and gneiss of unknown age. Few mineral deposits are known in the area and there has probably been only limited prospecting. There are ;.- no glaciers, but the topography is fairly steep and the lower elevations are heavily tree covered. The anomalies could be related to the granitic intrusions and there may be some potential for vein deposits 5 associated with them; the anomalies could also reflect the metal content of the gabbro complex and of the hornblende-bearing metamorphic rocks. D-42 9.1267 | The Excursion Inlet area in the Chilkat province (P on fig. A-l) i has many stream sediment samples with anomalous amounts of silver, I beryllium, cobalt, copper, mercury, nickel, lead, zinc, and gold. The ! t 4 bedrock consists of graywacke and argillite of Silurian age with some .thick non-fossiliferous limestone layers. Interpretation of the aeromagnetic data suggest that the bedrock conceals at shallow depth granodiorite and diorite of Jurassic or Cretaceous age which is exposed i j 8 nearby just outside the monument. Bedrock geochemical data are almost 9 wholly lacking and no mineral deposits are known in the area. The , _ available evidence suggests that the area has potential for skarn | i _ i n deposits and polymetallic veins. The area probably has not been explored i thoroughly, although prospecting would not be difficult and the area is j 13 relatively accessible. j i I 14 ', Other commodities and areas i Other commodities of possible mineral resource interest that either 16 occur or could logically occur in the monument based on the known ! 17 geology are coal, oil and gas, nuclear fuels, geothermal energy, and industrial minerals. Our investigations suggest it is unlikely that any of these commodities are present in amounts of economic significance. 23 D-43 - a GOVER.VMENT PRINTING OFFICE ! j?C O - 457-:,-34 9.1267 ' Conclusion ' 1 , I ' The material in chapters B and C shows that many areas other than 2 \ those discussed in this evaluation are known to contain mineral resources, 3 ' i This chapter necessarily emphasizes the most significant resources; they; t I i t j are in the areas that are best known geologically and geochemically. In c _ these areas our studies are adequate to establish the existence of 6 mineral resources, but in most other areas of the monument our work is probably not detailed enough to rule out the presence of significant 8 resources. ' 9 We consider the results of this evaluation a conservative estimate 10- of the mineral resources present in Glacier Bay National Monument. The 11 most ; monument is highly mineralized in comparison with/similar-size areas 12 , elsewhere in southeastern Alaska,and we believe it likely contains more 13 I deposits and favorable areas of the types described here and perhaps i D-44 ( 1 i Chapter E i 2 ; References i 4 i Anthony, L. M., 1977, unpublished maps and notes on investigations in ! 5~ Glacier Bay, 1958-1960: [available at U.S. Bureau of Mines ! 6 ; library, Juneau, Alaska]. 7 Atwater, T., 1970, Implications of plate tectonics for the Cenozoic 3 tectonic evolution of western North America: Geological Society 9 ; of America Bulletin, v. 81, p. 3513-3536. i 10 | Barnes, F. F., 1967, Coal resources of Alaska: U.S. Geological " ; Survey Bulletin 1242-B, 36 p. 12 ' Barnes, D. F., 1972, Southeast Alaska gravity base station network: i 13 U.S. Geological Survey Open-file Report, 40 p. 14 _____, 1977, Bouguer gravity map of Alaska: U.S. Geological Survey ' 5- \ Geophysical Investigations Map GP-913, scale 1:2,500,000. 16 i Barnes, D. F., Popenoe, Peter, Olson, R. C., MacKenzie, M. V., and ' 7 : Morin, R., 1972, Tabulated gravity data from southeastern Alaska ' a obtained during the 1969 field season: U.S. Geological Survey 17 Open-file Report, 75 p. :°- Barnes, D. F., Erwin, M. M., Holden, K. D., and Morin, R. L., 1975, -" Additional tabulated gravity data from the Port Alexander, 22 Sitka, Juneau, Mt. Fairweather and Skagway quadrangles, Alaska: -3 U.S. Geological Survey Open-file Report, 47 p. and 5 maps, scale 1:250,000. E-l Beikman, H. M., 1974(1975), Preliminary geologic map of the southeast quadrant of Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-612, scale 1:1,000,000. Berg, H. C., Jones, D. L., and Richter, D. H., 1972, Gravina-Nutzotin belt tectonic significance of an upper Mesozoic sedimentary and volcanic sequence in southern and southeastern Alaska, in Geological Survey Research 1972: U.S. Geological Survey Professional Paper 800-D, p. Dl-D-24. Brew, D. A., Carlson, Christine, and Nutt, C. J., 1976, Apparent pre-mid-Tertiary right-lateral offset on Excursion Inlet fault, Glacier Bay National Monument, in_ Cobb, E. H., ed., U.S. Geological Survey in Alaska: Accomplishments during 1975: U.S. Geological Survey Circular 733, p. 59. Brew, D. A., Grybeck, D., Johnson, B. R., and Nutt, C. J., 1976, Glacier Bay National Monument mineral-resource studies recommenced, in_ Cobb, E. H., ed., United States Geological Survey in Alaska: Accomplishments during 1975: U.S. Geological Survey Circular 733, p. 58-59. Brew, D. A., Johnson, B. R., Ford, A. B., and Morrell, R. P., 1978, Intrusive rocks in the Fairweather Range, Glacier Bay National Monument, Alaska, in_ Johnson, K. M., ed., The U.S. Geological Survey in Alaska: Accomplishments during 1977: U.S. Geological Survey Circular 772-B, p.___, (in press). E-2 9-1267 j Brew, D. A., Johnson, B. R., Nutt, C. J., Grybeck, Donald, and Ford, 2 I A. B., 1977, Newly discovered granitic and gabbroic bodies in i 3 i the Falrweather Range, Glacier Bay National Monument, Alaska, in i Blean, K. M., ed., The U.S. Geological Survey In Alaska: i 5~ i Accomplishments during 1976: U.S. Geological Survey 6 ; Circular 751-B, p. 90-91. 7 : Brew, D. A., Loney, R. A., and Muffler, L. J. P., .1966, Tectonic i ; history of southeastern Alaska: Canadian Institute of Mining I j and Metallurgy Special Volume, no. 8, p. 149-170. j i0~ ; Brew, D. A., Loney, R. A., Kistler, R. W., Czamanske, G. K., Gromme, ,, ! ! C. S., and Tatsumoto, M., 1977, Probable Precambrian or lower i 12 ; Paleozoic rocks in the Falrweather Range, Glacier Bay National i 13 ; Monument, Alaska, in_Blean, K. M., ed., The U.S. Geological i 4 | Survey in Alaska: Accomplishments during 1976: U.S. Geological ' 5~ i Survey Circular 751-B, p. 91-93. 16 i Brew, D. A., and Morrell, R. P., 1978, Tarr Inlet suture zone, 7 Glacier Bay National Monument, Alaska, in_ Johnson, K. M., ed., ' 3 The U.S. Geological Survey in Alaska: Accomplishments during ' ? ; 1977: U.S. Geological Survey Circular 772-B, p.____, (in "~ press). Brew, D. A., and Ovenshine, A. T., 1975, Summary of recent studies in 22 j Glacier Bay National Monument, Alaska, in_ Carter, Claire, ed., 23 , U.S. Geological Survey Alaska Program, 1974: U.S. Geological ;4 Survey Circular 700, p. 53-54- E-3 9-1267 "1 I Brooks, A. H., 1953, Blazing Alaska's trails: Fairbanks, University i of Alaska Press, ___p. Buddington, A. F., 1926, Mineral investigations in southeastern Alaska: U.S. Geological Survey Bulletin 783-B, p. 56-61. Buddington, A. F., and Chapin, Theodore, 1929, Geology and mineral deposits of southeastern Alaska: U.S. Geological Survey Bulletin 800, 398 p. Bugbee, E. E., 1940, A textbook of fire assaying: New York, N. Y., John Wiley and Sons, Inc., 314 p. Burchard, E. F., 1920, Marble resources of southeastern Alaska: U.S. Geological Survey Bulletin 682, p. 41-45, 114. 12 ____1941, Marble resources of the Juneau, Skagway and Sitka districts, in Mineral resources of Alaska, 1913: U.S. Geological Survey Bulletin 592-C, p. 98-101. Case, J. E., and MacDonald, W. D., 1973, Regional gravity anomalies and crustal structure in northern Columbia: Geological Society of America Bulletin, v. 84, p. 2905-2916. Cook, D. J., 1969, Heavy minerals in Alaskan beach sand deposits: University of Alaska Mineral Industry Research Laboratory Report no. 20, p. 47-57. Czamanske, G. K., Calk, L. C., Loney, R. A., and Himmelberg, G. A., 1977, The Srady Glacier Ni-Cu deposit, southeastern Alaska [abs.l Program with Abstracts, v. 2, 1977 Annual Meeting of the Geological Association of Canada, Vancouver, p. 14. E-4 9-1267 Ellett, R. D-, 1975, Statement and discussion: Adverse effects of proposed legislation upon Alaskan nickel mining, in The regulation of mining activities within areas of the National Park System: U.S. Congressional Senate Committee hearing before the Committee on Internal and Insular Affairs, October 7, 1975, 94th Congress, 1st Session, p. 311-336. Finch, W. I., Butler, A. P., Jr., Armstrong, F. C., Weissenborn, A. E., Staatz, M. H., and Olson, J. C., 1973, Nuclear fuels, in Brobst, D. A. and Pratt, W. P., eds., United States mineral 10 resources: U.S. Geological Survey Professional Paper 820, p. 455-468. Forn, C. L-, Hoffman, J. D., Sanzolone, R. F., and McDanal, S. K-, 13 1978, Magnetic tape containing results of semi-quantitative spectrographic, atomic absorption, and other analyses of bedrock 15 and stream sediment samples from the Glacier Bay National lo Monument Wilderness Study Area, Alaska: National Technical Information Service Report ERT-____, U.S. Department of Commerce, Springfield, Va. 22151. Fowler, Howard, 1950, Memorandum report to Leo H. Sarrela, Commissioner of Mines, on the LeRoy mines, Glacier Bay, Alaska: Territory of Alaska Department of Mines Property Examination 114-4, 2 p. Graf, J. L., Jr., 1977, Rare earth elements as hydrothermal tracers during the foramtion of massive sulfide deposits in volcanic ____rocks ^__Ej:onojaic__Geologyj._y_?_72_,_nq._4_,_p_L 527.______.______E-5 """" """" 9 12*>/ Gumma, William, Couch, R. W., and Gemperle, Michael, 1973, Submarine faults in Glacier Bay, Alaska: EOS, Transactions American Geophysical Union, v. 54, no. 3, p. 141. Hodge, E. T., 1944, Limestones of the Pacific northwest: Bonnevile A Power Administration, Division of Industry and Resource Development, Industrial Analysis Section, p. 18. Holdsworth, P. R., 1955, Mt. Parker mine, Mt. Fairweather quadrangle: Territory of Alaska Department of Mines Property Examination 115-5, 3 p. 10 Hutchinson, R. W., 1973, Volcanogenic sulfide deposits and their metallogenic significance: Economic Geology, v. 68, no. 8, 12 p. 1228-1246. Johnson, B. R., 1978, Statistical analysis of geochemical data from Glacier Bay National Monument, Alaska: U.S. Geological Survey Open-file Report 78-495. Johnson, B. R., Forn, C. L., Hoffman, J. D., Brew, D. A., and Nutt, C. J., 1977, Geochemical sampling of stream sediments, Tracy Arm, southeastern Alaska, in_ Blean, K. M., ed., The United States Geological Survey in Alaska: Accomplishments during 1976: U.S. Geological Survey Circular 751-B, p. B80-B82. Jones, D. L., Silberling, N. J., and Newhouse, JsKn , 1978, 22 Wrangellia - a displaced terrane in northwestern North America: Canadian Journal of Earth Science, v. 14, no. 11, p. 2365-2577. E-6 9-1267 ! Kennedy, G. C., and Walton, M. S., Jr., 1946, Geology and associated mineral deposits of some ultrabasite rocks in southeastern Alaska: U.S. Geological Survey Bulletin 947-D, p. 65-84. Koo, Jahak, and Mossman, D. J., 1975, Origin and metamorphism of the 5 Flin Flon stratabound copper-zinc sulfide deposit, Saskatchewan and Manitoba: Economic Geology, v. 70, no.-l, p. 48. Large, R. R., 1977, Chemical evolution and zonation of massive sulfide deposits in volcanic terrains: Economic Geology, v. 72, no. 4, p. 549-573. Lathram, E. H., Loney, R. A., Condon, W. H., and Berg, H. C., 1959, Progress map of the geology of the Juneau quadrangle, Alaska: U.S. Geological Survey Map 1-303, scale 1:250,000. Levinson, A. A., 1974, Introduction to exploration geochemistry: Applied Publishing, Limited, Calgary, Alberta, 612 p. 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