University of Calgary PRISM: University of Calgary's Digital Repository
Graduate Studies Legacy Theses
1999 Sedimentology and stratigraphy of placer gold deposits of Haggart Creek, central Yukon territory
Weston, Leyla Halide
Weston, L. H. (1999). Sedimentology and stratigraphy of placer gold deposits of Haggart Creek, central Yukon territory (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/11076 http://hdl.handle.net/1880/25379 master thesis
University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca NOTE TO USERS
This reproduction is the best copy available.
UMI
THE UNIVERSITY OF CALGARY
Sedimentology and Stratigraphy of Placer Gold Deposits of Haggart Creek,
Central Yukon Territory
by
Leyla Halide Weston
A THESIS
SUBMITTED TO THE FACULTY OF GMDUATE STUDIES
IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE
DEGREE OF MASTER OF SCIENCE
DEPAR'TXENT OF GEOLOGY AND GEOPHYSICS
CALGARY, ALBERTA
MAY, 1999
O Leyla Halide Weston 1999 National Library Bibiiotheque nationale of Canada du Canada
Acquisitions and Acquisitions et Bibliographic Services services bibliographiques 395 Wellington Street 395, rue Wellington Ottawa ON K1A ON4 Ottawa ON K1A ON4 Canada Canada Your fils Votnr rehrmca
Our fib Nofre reUrence
The author has granted a non- L'auteur a accorde une licence non exclusive licence allowing the exclusive pennettant a la National Library of Canada to Bibliotheque nationale du Canada de reproduce, loan, distribute or sell reproduire, prster, distribuer ou copies of hsthesis in microform, vendre des copies de cette these sous paper or electronic formats. la fone de microfiche/fih, de reproduction sur papier ou sur format electronique.
The author retains ownership of the L'auteur conserve la propriete du copyright in this thesis. Neither the droit d'auteur qui protege cette these. thesis nor substantial extracts fiom it Ni la these ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent etre imprimes reproduced without the author' s ou autrement reproduits sans son permission. autorisation. ABSTRACT
Haggart Creek study area contains unconsolidated sediments, which represent six main geomorphic settings: 1) Reid-age glacial and glaciofluvial deposits; 2) McConnell-
age proximal braided stream deposits to periglacial alluvial fans; 3) McConnell-age medial to distal braided stream deposits; 4) post-McConnell wandering gravel bed river;
5) Holocene gulch deposits; and 6) Holocene colluvium.
Placer gold within the study area is known to originate f?om at least two main
local lode sources: 1) gold in sheeted quartz veins within a Late Cretaceous-age
granodiorite stock; and 2) gold in isolated wartz-sulphide fissure veins found in bedrock along Haggart Creek. Placer gold is believed to have formed as a result of reworking and reconcentration of gold during interglacial times, as well as reworking of older auriferous
interglacial gravel by McComell-age periglacial alluvium. The primary setting for placer gold deposits is Late Mcconnell to Early Holocene alluvium, on or near bedrock. Sub- crystalline to crystalline placer gold grains recovered from sediments found far removed
from currently known local bedrock sources suggests that other lode sources may be present within the study area.
iii ACKNOWLEDGEMENTS
I would like to take this opportunity to express my gratitude to those people and organizations that made this thesis possible. Thank you to my supervisor Dr. Fran Heh for your support, guidance, direction and patience. Thank you Bill LeBarge, for without your initiative, financial support and enthusiasm, this project never would have existed.
Thank you Jerry "Saturday Night Fever" Osborn for rewriting my thesis. Thank you Dr.
Gerald Smith for your patience and support during a confbsing defense time. Thank you to NSTP (Northern Science Training Program) for the research grant which made my research during the summer field season of 1997 that much more enjoyable. A very big thank you goes out to my field assistant Lisa MacKinnon; thank you Lisa for your endless help and your wonderful spirit. Thank you Deb Gladiotis (University of Calgary) for your assistance with the scanning electron microscope; your wondehl good humour and patience helped immensely.
A special thanks goes out to all the placer miners in the area. Thank you Ron
Holway, Fred Holway (and crew) and Ted Tackus for your kindness and cooperation.
This project would have not been possible without you.
Thank you Duane Froese, who is always willing to talk shop! Thank you to all my friends and family for your encouragement, love and support. Thank you especially to all my friends in Whitehorse (you know who you are), without you, I may have completed this thesis a year ago!
Most of all, I thank Jeff for all your help, support and for keeping me sane. I truly did find the gold in Mayo. TABLE OF CONTENTS
CHAPTER 1.1 ...... 1 1.1 INTRODUCTION ...... 1 1.2 LOCATIONOF STLJDYAREA ...... 3 1.3 PREVIOUS RESEARCH ...... 4
CHAPTER 2 - BEDROCK GEOLOGY ...... ~.~~~~~~7 2.1 TECTONIC ASSEMBLAGES AND REGIONAL GEOLOGY OF YUKON ...... 7 2.2 LOCAL GEOLOGY AND METALLOGENY ...... 10
CHAPTER 3 .PHYSIOGRAPHIC SETTING AND GLACIAL HISTORY ...... 15 3.1 PHYSIOGRAPHY OF YUKON ...... 15 3.2 LOCAL PHYSIOGRAPHY ...... 17 3.3 CLIMATE ...... IS 3.4 PERMAFROST, SOILS AND VEGETATION ...... 19 3.5 REGIONAL GLACIAL HISTORY ...... 21 3.6 LOCAL GLACIAL HISTORY ...... 23 3.7 LOCAL SURFlCIAL GEOLOGY ...... 24
CHAPTER 4 .METHODOLOGY ...... 0...6 4.1 INTRODUCTION ...... 26 4.2 SEDIMENTOLOGY ...... , ...... 26 4.3 SAMPLING PROCEDURES...... 29
CHAPTER 5 = SEDIMENTARY FACIES AND FACIES ASSOCIATIONS ...... 30 5.1 INTRODUCTION ...... 30 5 -2 SEDIMENTARY FACIES DESCRIPTIONS ...... -30 5.2.1 Facies 1 : Massive to crudely bedded gravel (Gm) ...... 30 5.2.2 Facies 2: Crudely graded, horizontally stratified gravel (Gh) ...... 32 5.2.3 Facies 3: Stratified gravel with planar tabular crossbeds (Gp) ...... 34 5.2.4 Facies 4: Stratified gravel with trough crossbeds (Gt) ...... 35 5.2.5 Facies 5: Horizontally laminated sand, and pebbly sand (Sh) ...... 35 5.2.6 Facies 6 and 7: Crossbedded sand and pebbly sand (Sp and St)...... 35 5.2.7 Facies 8: Sand. very fine to very coarse with ripple marks (Sr)...... 38 5.2.8 Facies 9: Sand. silt and mud with tine laminations (Fl) ...... 38 5.2.9 Facies 10: Massive silt (Fm)...... 42 5.2.10 Facies 1 1 : Organics and organic-rich silt (Fo)...... 42 5.2.12Facies 12: Massive to weakly stratified, matrix-supported gravel diarnict (Dms)...... ,,., ...... 44 5.2.13 Facies 13: Massive, matrix-supported gravel diamict (Dmm)...... 14 5.3 FACIES ASSOCIATIONS ...... 48 5.3.1 Facies Association I : Proximal braided stream to alluvial fan (Facies Gm, Gh, Dms) ...... -48 5.3.2Facirs Association 2: Medial to distal braided stream (Facies Gm,Gp, Gt, Sp, St, Sr and Sh)...... 49 5.3.3 Facies Association 3: Wandering gravel bed river (Facies Gm, Sp, St and Sh).. 49 5.3.4Facies Association 4: Gulch deposits (Facies Gm, Gh)...... 50 5.3.5 Facies Association 5: AeoIian-colluvial (Facies FI. Fm. Fo, and Drns) ...... 50 5.3.6 Facies Association 6: Glacial deposits (Facis Drnm, Sh and Gm) ...... SO
CHAPTER 6 DEPOSITIONAL PROCESSES~s~ossoao~~ooooooo~.mooeooeasoa*oo~o~o.a. oosoa*oos.o 0.53 6 .I GRAM-S IZE CHARACTERISTICS...... -53 6.1.1 Introduction ...... 53 6.1.2 Discussion...... 54 6.2 CLAST LITHOLOGY AND PROVENANCE ...... 59 6.2.1 Introduction ...... 59 6.2.2 Discussion ...... 60
CHAPTER 7 PLACER GOLD MINERALIZATIONoos~eoeaoooooooooosoo.oaoomo.aoooosssoooosaooooo61 7.1 SEM ANALYSIS AND GOLD MORPHOLOGY...... I 7.1 .1 Introduction ...... ,.,...... 6 1 7.1.2 Discussion...... 62 7.2 HEAVY-MINERAL ANALYSIS ...... 68 7.2.1 Introduction ...... 68 7.2.2 Discussion ...... 69 7.3 CONTROLLING MECHANISMS FOR PLACER GOLD MINERALIZATION
7.3.1 Bedrock sources ...... 72
7.3.2 Paleoenvironrnentalcontrols ...... ,...... 73 7.3.3 Sedimentological and hydrological controls...... 75
CHAPTER 8 STRATIGRAPHY AND PALEOGEOGIUPHIC RECONSTRUCTIONmaeeaaaooemamweeaaeaemaaa*eaa.mo**oeeea ...e..e...e....ee..e.e...... e...mmm...aeee.ee.mm..eee.....77 8.1 INTRODUCTION ...... -77 8.2 SCHEMATIC PROFILES AND FACIES ASSOCIATIONS ...... 77 8.2.1 Fisher Gulch...... 77 8.2.2 Dublin Gulch...... 1 8.2.3 Haggart Creek (right-limit near Gill Gulch) ...... 90 8.2.4 Haggart Creek (lefi~limit.downstream of Platinum Gulch) ...... 101 8.2.5 Haggart Creek (right-limit near 1 5 Pup)...... 117 8.3 SCHEMATIC PROFILES AND LATERAL RELATIONSHIPS...... I27
8.3.1 Dublin Gulch ...... ,., ...... *...... 127 8.3.2 Haggm Creek (right-limit near Gill Gulch) ...... 128 8.3.3 Haggart Creek (left-limit. downstream of Gill Gulch and Platinum Gulch) ...... I29 8.3.4 Haggart Creek (right-limit near 1 5 Pup) ...... 130 5.4 PALEOGEOGRAPHIC RECONSTRUCTION...... 131 8.4.1 Introduction...... 131 8.4.2 Discussion ...... 131
CHAPTER 9 CONCLUSIONSaaeoaaaa...... *.el44 9.1 CONCLUSIONS ...... 144 9.1.1 Summary of Sedimentology and Stratigraphy...... 144 9.1.2 Summary of Placer Gold Settings...... 146
REFERENCES ...... aa.aaaaamaeaaeaaaa~aamea.aaea.a~aa...aaamea.aa~aaaaaae~ama~a...... 149 APPENDIX A: GRAIN SIZE ANALYSIS .. DATA AND RESULTS...... I57
vii APPENDIX B: FABRIC DATA AND CLAST LITHOLOGIES...... ,.....159 APPENDIX C: MEASURED SECTIONS...... 89
viii LIST OF FIGURES
Figure 1.1: Glacial limits map, Yukon Temtory; note location of Haggart Creek study area (from Duk-Rodkin, 1998)...... 2
Figure 1.2: Location of Haggart Creek study area...... (in pocket)
Figure 2.1: Location of morphological belts of the Western Cordillera, including the Yukon (from Gabrielse et al., 199 1)...... 8
Figure 2.2: Location of terrane assemblages and selected mineral deposits within Yukon Temtory (modified from Wheeler et al.. 199 1 and Yukon Minfile)...... 9
Figure 2.3: Geology of Haggart Creek area (from Boyle, 1965)...... I 1
Figure 2.4: General geology and mineral deposits of Dublin Gulch area, Haggart Creek drainage basin (from Boyle, 1979)...... 13
Figure 3.1 : Physiographic subdivisions of Yukon Territory; note location of Haggart Creek study area (modified from Bond, 1997~)...... 16
Figure 3.2: Glacial limits and ice flow patterns, Mayo area, Central Yukon ...... ( in pocket)
Figure 3.3: Permafrost distribution. Yukon Territory (from Heginbottom et al., 1995). ..10
Figure 3.4: Reid terrace exposed as a till blanket in a mining cut near the mouth of Dublin Gulch. Exposed section is approximately 12.5 metres thick...... 25
Figure 4.1 : Haggart Creek study area and site locations...... 27
Figure 5.1: Weakly imbricated, clast-supported, pebble-cobble gravel (Facies Gm) on right-limit of Haggart Creek. Flow is from left to right. Rock hammer measures 30 cm. .*...... *....,...... *...... *...... -...... *...... 3 1
Figure 5.2: Massive to crudely graded, poorly sorted gravel (Facies Gh) from Fisher Gulch; trowel is approximately 20 cm long...... 33
Figure 5.3: Moderately to well-sorted, matrix-filled, pebble-cobble gravel with trough crossbeds. . (Facies Gt) from left-limit of Haggart Creek. Spacing between yellow flagg~ngIS 1 m...... 36
Figure 5.4: Moderately to well sorted, horizontally laminated sand (Facies Sh) within crudely stratified gravel (Facies Gm) from Dublin Gulch. Lens cap is 6 crn in diameter...... 37
Figure 5.5: lnterbedded facies of planar crossbedded sand and pebbly sand (Sp) with planar crossbedded gravel (Gp) from right-limit of Haggart Creek. Dip on foresets is approximately 20; flow is fiom right to left on photograph. Pogo measures 1.5 m. .39 Figure 5.6: Discontinuous lenses of laminated fine sand and silt (Facies Fl) within heavily cryoturbated pebbly diamict (Facies Dms) from Gill Gulch. Pen is 15 cm..40
Figure 5.7: Ice wedge cast cuts organic-rich, laminated silt and fine sand (Facies Fl) and pebbly diamict (Dms) from Gill Gulch. Entire unit dispiays extensive mixing due to cryoturbation. Pen measures 15 cm...... 4 1
Figure 5.8: Massive, buff-coloured medium to coarse silt (Facies Fm) overlying weakly stratified and crudely graded gravel (Facies Gh) from Gill Gulch. Lenscap is 6 cm in diameter...... 43
Figure 5.9: Massive?very poorly sorted, matrix-supported, pebble-cobble diamict (Facies Dms) from Gill Gulch. Note large piece of woody debris and rip-up clasts of organic-rich silt. Lens cap is 6 cm in diameter...... 45
Figure 5.10: Weakly stratified, poorly sorted, matrix-supported, pebble diamict (Fac ies Dms) from left-limit of Haggart Creek. Note a-axis alignment of clasts parallel to slope (above pen). Pen measures 15 cm...... 46
Figure 5.11: Highly competent, massive, matrix-supported, gravel diamict (Facies Dmm) from left-limi t of Haggart Creek. Length of shovel handle in picture is 25 crn...... 47
Figure 6.la: Summary of grain-size results of alluvial gravel samples from Haggart Creek and Gill Gulch...... 55
Figure 6.1 b: Summary of grain-size results of alluvial gravel samples from Gill Gulch and Fisher Gulch...... 56
Figure 6.1 c: Summary of grain-size results from: alluvial gravel (Dublin Gulch); till (Dublin Gulch) and resedimented till (Haggart Ck.); and debris flows (Dublin Gulch and Haggart Ck.)...... 57
Figure 7.1: Scanning electron photomicrograph of gold grain from alluvial gravel on the right-limit. . of Haggart Creek (LW-97-26-U I ). Note composite nature of the grain, told~ngand rounding ...... 63
Figure 7.2: Scanning electron photomicrograph of gold grain from an alluvial gravel on the left-limit of Haggart Creek (LW-97-01-U1).Grain is sub-crystalline with folded extensions and pitted surface texture...... 63
Figure 7.3: Scanning electron photomicrograph of gold grain from alluvial gravel at Fisher Gulch. Grain is composite and sub-crystalline...... 64
Figure 7.4: Scanning electron photomicrograph of gold grain from alluvial gravel at Dublin Gulch. Grain represents slightly rounded wire gold ...... 64
Figure 7.5: Scanning electron photomicrograph of gold grain from alluvial gravel on the right-limit. . of Haggart Creek (LW-97-26-Ul). Grain is rounded; note shearing and stnat~ons...... 65 Figure 7.6: Scanning electron photomicrograph of gold grain from alluvial gravel at Gill Gulch (GILL4). Grain is sub-crystalline with highly pitted surface texture...... 65
Figure 7.7: Scanning electron photomicrograph of gold grain from alluvial gravel at Gill Gulch (Pay). Gold grain is sheared exposing crystal faces...... 66
Figure 7.8: Scanning electron photomicrograph of gold grain from alluvial gravel on the right-limit of Haggart Creek. Specimen is a sub-rounded gold grain with an embedded feldspar grain...... 66
Figure 7.9: Weathered out quartz-arsenopyrite-pyrite-scorodite-gold vein within schist bedrock on Haggart Creek. near Gill Gulch. Note high clay content. Hammer measures 30 cm...... -74
Figure 8.1: Photo of Fisher Gulch on the right-limit of Haggart Creek, upstream of Dublin Gulch. Note the steep slopes in a narrow, confined valley...... 78
Figure 8.2: Vertical logged section of LW-97- 16 on Fisher Gulch...... 79
Figure 8.3: Vertical logged section of LW-97- 17 on Fisher Gulch...... 80
Figure 8.4: Photo of section LW-97-2 1 on the left-limit of Dublin Gulch showing a relatively thick package of proximal alluvial fan gravel (facies association 1 ). Measured section is approximately 13.7 m thick...... 82
Figure 8.5: Vertical logged section of LW-97-2 I on the left-limit of Dublin Gulch...... 53
Figure 8.6: Photo of section LW-97-22 on the left-limit of Dublin Gulch showing a pre- Reid debris flow underlying Reid till. Measured section is approximately 13.7 rn thick...... 85
Figure 8.7: Vertical logged section of LW-97-22 on the left-limit of Dublin Gulch...... 86
Figure 8.8: Photo of erosional contact between pre-Reid debris flow and overlying Reid till of section LW-97-22 on the left-limit of Dublin Gulch. Pen measures 15 cm.... 87
Figure 8.9: Vertical logged section of LW-97-23 on the left-limit of Dublin Gulch...... 88
Figure 8.1 0: P hot0 of alternating beds of horizontally stratified sand and pebbly sand (facies Sh) with beds of well-sorted, imbricated. pebble gravel (facies Gm) of section LW-97-23 on the left-limit of Dublin Gulch. Shovel measures approximately 1.2 m...... A9
Figure 8.11: Photo of section LW-97-I0 on the right-limit of Haggart Creek near Gill Gulch. Measured section is approximately 4.85 m thick. The lowermost alluvial gravel unit is interpreted to represent an abandoned alluvial terrace...... 9 1
Figure 8.12: Vertical logged section of LW-97- 10 on the right-limit of Haggart Creek ...... near Gill Gulch...... 92 Figure 8.13: Photo of site locations on the right-limit of Haggart Creek near Gill Gulch (LW-97- ). Flow of Haggart Creek is from right to left in the photo ...... 94
Figure 8.14: Photo of section LW-97-11 on the right-limit of Haggart Creek near Gill Gulch. Pogo measures L.25 m...... 95
Figure 8.15: Vertical logged section of LW-97- I1 on the right-limit of Haggart Creek near Gill Gulch...... 96
Figure 8.16: Vertical logged section of LW-97- 14 on the right-limit of Haggart Creek near Gill Gulch...... 98
Figure 8.17: Photo of section GILL3 on the right-limit of Haggart Creek near Gill Gulch. Measured section is approximately 7.3 m thick...... 99
Figure 8.18: Vertical logged section of GILL3 on the right-limit of Haggart Creek near Gill Gulch...... 100
Figure 8.19: Vertical logged section of GILL4 on the right-limit of Haggan Creek near Gill Gulch...... ,...... 102
Figure 8.20: Vertical logged section of LW-97-15 on the left-limit of Haggart Creek downstream of Platinum Gulch...... 103
Figure 8.21: Vertical logged section of LW-97-08 on the left-limit of Haggart Creek downstream of Platinum Gulch...... 105
Figure 8.22: Photo of section LW-97-01 on the left-limit of Haggart Creek, downstream of Platinum Gulch. Measured section is approximately 32 rn thick ...... 107
Figure 8.23: Vertical logged section of LW-97-0 1 on the left-limit of Haggart Creek downstream of Platinum Gulch...... +...... ~...... 108
Figure 8.24: Vertical logged section of LW-97-03 on the left-limit of Haggart Creek downstream of Platinum Gulch...... ,., ...... 1 10
Figure 8.25: Photo taken adjacent to section LW-97-03 on the left-limit of Haggart Creek showing a typical medial to distal braided stream sequence (facies association 2). Exposed section is approximately 24 m thick ...... I 1 I
Figure 8.26: Photo of section LW-97-02 on the left-limit of Haggart Creek downstream of Platinum Gulch. Measured section is approximately 13 rn thick...... 112
Figure 8.27: Vertical logged section of LW-97-02 on the left-limit of Haggart Creek downstream of Platinum Gulch...... I 13
Figure 8.28: Photo of section LW-97-05 on the left-limit of Haggart Creek downstream of Platinum Gulch. Measured section is approximately 13.5 m thick...... 11 5
xii Figure 8.29: Vertical logged section of LW-97-05 on the left-limit of Haggart Creek, downstream of Platinum Gulch...... 1 16
Figure 8.30: Vertical logged section of LW-97-24 on the right-limit of Haggart Creek near 15 Pup...... 118
Figure 8.31: Photo of section LW-97-25 on the right-limit of Haggart Creek near 15 Pup. Pogo measures 1.25 m...... 1 19
Figure 8.32: Vertical logged section of LW-97-15 on the right-limit of Haggart Creek near 1 5 Pup...... 1 20
Figure 8.33: Vertical logged section of LW-97-26 on the right-limit of Haggart Creek near 1 5 Pup...... 122
Figure 8.34: Photo of imbricated pebble-cobble gravel of unit I of section LW-97-26 on the right-limit of Haggart Creek near 15 Pup. Piece of wood in photo yielded a radiocarbon age of 6040 70 BP...... 123
Figure 8.35: Photo of section LW-97-27 on the right-limit of Haggart Creek near 15 Pup. View is looking upstream on Haggart Creek. Pogo measures 1.25 m...... 125
Figure 8.36: Vertical logged section of LW-97-27 on the right-limit of Haggart Creek near 15 Pup...... 126
Figure 837: Stratigraphic correlation of Dublin Gulch...... (in pocket)
Figure 8.38: Stratigraphic correlation of Haggart Creek near Gill Gulch ...... ( in pocket)
Figure 8.39: Stratigraphic correlation of Haggart Creek downstream of Platinum Gulch ...... (in pocket)
Figure 8.40: Stratigraphic correlation of Haggart Creek near 15 Pup ...... (in pocket)
Figure 8.41: This environmental reconstruction shows the Reid glacier advancing up Haggart Creek valley. The valley glacier would have had limited energy to erode its base due to the valley's orientation being transverse to regional ice flow patterns, therefore ice would be advancing up-valley, or up-gradient. Thick deposits of basal till, outwash and likely glacio-lacustrine sediments would have capped pre-Reid interglacial sediments in Haggart Creek valley, following the Reid glaciation ...... 134
Figure 8.42: Environmental reconstruction of Haggart Creek during the Koy-Yukon interglacial. Haggart Creek has downcut into underlying Reid glacial sediments (remnant bench on right side of creek in figure) and has begun reworking previously buried gold-bearing pre-Reid interglacial deposits. The Koy-Yukon interglacial had a warmer and more humid climate than the current interglacial period...... 136
.*. Xlll Figure 8.43: The periglacial environment that affected Haggart Creek during the McCo~ellglaciation increased sedimentation throughout the drainage. Physical weathering combined with increased precipitation caused Haggart Creek to become a braided stream. Koy-Yukon interglacial deposits were reworked into this periglacial alluvium. The periglacial conditions may have also assisted in the transport of interglacial eluvial gold placers into the fluvial systems...... 138
Figure 8.44: During the late McConneII, the climate moderated and sedimentation decreased in Haggart Creek drainage. A wandering gravel bed river developed that began to incise into the underlying braided stream deposits. Where the braided deposits were thin, Haggart Creek incised to bedrock and reworked underlying interglacial placer gold deposits...... 140
Figure 8.45: A view looking north of modem Haggart Creek. The stream meanders between the confines of the remnant periglacial fans and colluvium derived from permafrost-enriched surficial deposits. The meandering stream has relatively low energy and is not in contact with bedrock in the core of the valley...... 143
xiv LIST OF TABLES
Table 4.1. Section locations for Haggart Creek study area ...... 28
Table 5.1. Summary of facies and facies associations ...... -52
Table 6.1 : Summary of clast provenance ...... 60
Table 7.1 : Summary of gold grain roundness ...... 61
Table 7.2. Summary of gold morphology from SEM analysis...... 62
Table 7.3~Summary of results for heavy-mineral analysis for Haggart Creek and Dublin Gulch ...... 70
Table 7.3b: Summary of results for heavy-mineral analysis for Gill Gulch and Fisher Gulch ...... 7 l CHAPTER 1
1.1 Introduction
Yukon Territory has become well known for its economic deposits, and mining
remains one of the most important driving forces in the economy of Yukon today. The
placer industry began with the Klondike Goldrush of 1898 and still more than 100 years
later the placer industry remains a significant part of Yukon's mining industry. The fust
recorded gold mining took place in 1886, and since then, over 15 million crude ounces of
placer gold have been produced (LeBarge, 1997). Production has generally followed the
fluctuating price of gold. Since 1987, production has averaged over 126,000 ounces per
year, with a peak of 165,571 ounces in 1989; production has not dropped below 100,000
ounces since 1986 (LeBarge, 1997). Presently, as in the past, most gold production has
come fiom the unglaciated regions of Yukon. Recent production records have shown that
of the 1,966,190 crude ounces mined between 1978 and 1996,86.14% has come from
unglaciated areas, while 13.86% was mined from glaciated areas (LeBarge, 1997).
The southern and central parts of Yukon Territory have been extensively glaciated
throughout Pleistocene time. At least three main glacial events have affected these areas
with each glacial event less extensive than the previous. From oldest to youngest, the main glacial events are the Pre-Reid (multiple glacial episodes), Reid and McComell glaciations (figure 1.1) (Hughes et al. 1969). The Mayo area, central Yukon, differs fiom the unglaciated Klondike region in that it has undergone multiple glaciations during the
Late Cenozoic. The Mayo mining district (figure 1.2, in pocket), unlike the Klondike, was developed for its lucrative silver and galena deposits, however, small-scale placer Figure 1.1 : Glacial limits map, Yukon Territory; note location of Haggart Creek study area (fiom Duk-Rodkin, 1998). gold mining has been the most consistent economic producer for this region since the turn
of the century. Recent stratigraphic studies in neighbouring placer creeks suggest the
placer geology may be largely controlled by the complex interaction of glacial and
interglacial depositional cycles. Sedimentological and stratigraphic investigations of the
placer gravel may establish an origin for these deposits and possibly create a model for
other placer streams in glaciated regions of Yukon.
Due to the depletion of economic gold placer deposits in unglaciated areas of Yukon,
it is important to better understand the evolution of placer gold deposits in those glaciated
regions. The objectives of this study are to investigate the sedimentary properties of the
glacial and interglaciai sediments overlying the placer gold bearing deposits in the
Haggart Creek drainage basin in order to document: (I) the stratigraphic and
sedimentologic characteristics of the glacial sediments; (2) the relationship of these
characteristics to the preservation of gold bearing gravel; and (3) any unique features that
may aid in identifying potential placer deposits in other glaciated areas. This project aims
to unfold the complex history of these glaciated terrains in hopes to develop a model, which may be used for future reference in placer gold exploration. This project is
important for the further development and success of existing, as well as future placer mining operations in the Yukon.
1.2 Location of Study Area
The study area is located within the Mayo Mining District, central Yukon, approximately 400 km by road north of Whitehorse (figure 1.2, in pocket). The area is part of the Stewart Plateau, northeast of the Tintina Trench, and is proximal to the southern foothills of the Ogilvie Mountains. Haggart Creek drainage basin is located
approximately 85 krn north of Mayo; access to the area is by the Silver Trail highway and
the South McQuesten road. Helicopters may also be hired in Whitehorse or Mayo.
Haggart Creek is one of the principal tributaries of the South McQuesten River
and lies within NTS map sheets 106D/4,105W13 and 1 15P/16 (figure 1.2, in pocket).
Haggart Creek is over 33 km long and flows generally south-southwest into the South
McQuesten River. Tributaries to Haggart Creek that should be noted are the 'right-limit
tributaries Gill Gulch and Fisher Gulch, and the 'left-limit tributary Dublin Gulch; these
tributaries lie within NTS map sheet 106D/4.Lynx Creek is a morphoIogica1 extension
of Haggart Creek and lies within NTS map sheets 106D/4and 105W 1 3.
1.3 Previous Research
Some of the earliest work conducted in the region was completed by R.G.
McComell in 1901. McConnell examined bedrock and placer geology along the lower
reaches of the Stewart River and the Tintina trench. He was the first to describe the
Quaternary Geology of the area, noting late Wisconsinan morainal deposits along the
Stewart River. These deposits belong to what is now termed the McCo~ellglaciation.
H.S.Bostock (1948) expanded on the Quaternary history of the Yukon by noting older glacial deposits beyond the McConnell glacial limit. In 1966, Bostock defined the
- - Right-limit refers to the right-hand side of a creek when looking downstream.
Left-limit refers to the left-hand side of a creek when looking downstream. glacial limits for four glacial episodes in central Yukon; these glacial episodes from
oldest to youngest were named Nansen, Klaza, Reid and McConnell.
In 1969, Hughes et al. completed a study south of 65 degrees north latitude, which
included glacial limits and flow patterns of central Yukon. In this study, Hughes noted
difficulties in discerning between the older deposits of the Nansen and Klaza glaciations,
and so grouped these into what is now known as the Pre-Reid multiple glacial event.
Later, O.L. Hughes (1982) expanded on his work with the publication of a series of 1: 100
000 scale surficial maps of the Mayo area.
Some of the earlier bedrock mapping of the area was completed by K.C.
McTaggart in his 1960 GSC report. McTaggart's report included the geology of Keno
and Galena Hills, central Yukon, which host one of the largest silver, lead and zinc
deposits of Yukon. Active mining in the area lead to further research by R.W. Boyle,
who focused on the geochemistry of these deposits (Boyle, 1956, 1965; Boyle et al. 1955;
Gleeson and Boyle 1976). In 1970, L.H. Green completed a bedrock geology study of
Mayo Lake, Scougale Creek and McQuesten Lake map areas, central Yukon (Green,
197 1).
More recently, numerous researchers have completed Quaternary-related studies in the central Yukon. Hughes et al. (1972 and 1989), examined the Quaternary stratigraphy and history of the Cordilleran ice sheet, as well as the Quaternary geology and geomorphology of the southern and central Yukon. Duk-Rodkin and Froese (1995), and Duk-Rodkin et al. (1 993, examined the origin and extent of drift cover, as well as documented the Mid to Late Cenozoic glaciations in the northern Canadian Cordillera. Placer geology related studies have been numerous in central Yukon, however,
most of these studies concentrate on unglaciated regions. Morison (1985) examined the
sedimentology of the White Channel placer deposits, central Yukon. Froese (1997)
completed a recent study on the Plio-Pleistocene Klondike Terraces and their relationship
to placer development and preservation. Knight et al. (1994) discussed the shape and
composition of lode and placer gold fiom the Klondike district. In glaciated regions of
central Yukon, Morison (1 983), LeBarge (1995), and Levson (1992) conducted studies
concentrating on the sedimentology of Pleistocene deposits associated with placer gold-
bearing gravel.
In the Mayo area, Giles ( 1993), discussed the Quaternary sedimentology and
stratigraphy of the Mayo region. More recent work completed by LeBarge ( 1996)
examined the sedimentology and stratigraphy of the Duncan Creek placer deposits,
paying particular attention to facies interpretations and lithostratigraphic relationships.
Hein and LeBarge (1 997) discussed the geologic setting and framework of placer deposits in the Mayo area. A glacial history and placer gold potential study of the North
McQuesten River, Dublin Gulch and Keno Hill map areas was completed by J.D. Bond
( 1997a).
Few studies have been completed in the area of the Haggart Creek drainage basin.
Hitchins and Orssich (1995) examined the mineralization of the Dublin Gulch gold porphyry deposit. Smit et al. (1 995) released a summary information report regarding the
Dublin Gulch gold porphyry deposit. In 1996, Harington released a report on the
Pleistocene mammals of Dublin Gulch and the Mayo District. CHAPTER 2 - BEDROCK GEOLOGY
2.1 Tectonic Assemblages and Regional Geology of Yukon
The Yukon Territory contains the northernmost extension of the Western Cordillera
and is composed of an ancient North American craton onto which exotic terranes accreted
during Mesozoic time (Templeman-Kluit, 1979% 198 1; Monger et al., 1982; Gabrielse et
al., 199 1). Five northwest-trending morphological belts have been identified in Yukon,
these are from west to east the Insular, Coast, Intermontane, Omenica and Foreland Belts
(figure 2.1 ). Each of these morphological belts consists of several terranes, which host a
variety of mineral deposits (figure 2.2).
The Foreland Belt represents sediments deposited along the western margin of the
ancient North American craton. Sediments were deposited on stable platforms
(Mackenzie and Cassiar Platforms), which ultimately fed the Selwyn Basin (Templeman-
Kluit, 1979b and 198 1). Rock types found in this area range in age from Mid-Proterozoic
to Late Paleozoic and consist of shallow- to deep-water carbonates and clastics. The
Omenica Belt is a composite tenane composed of Late Proterozoic to Upper Paleozoic
metamorphic rock assemblages (Monger, 1989). The Intermontane Belt is composed of
five terranes and consists of volcanic and sedimentary rocks ranging in age between 320
and 190 million years old (Irving and Wynne, 1992; Monger, 1 989; Monger et al., 1982).
The Coast Belt is composed almost entirely of the Coast Plutonic Complex and consists predominantly of felsic plutons, with lesser amounts of marble, granulitic gneiss and schist (Coney, 1989). The Coast Plutonic Complex ranges in age from 185 to 55 million years (Monger, 1989). The Insular Belt consists of volcanics, clastics and limestone EXPLANATION
[ ] Pericratonic and displaced terranes
Figure 2.1 : Location of morphological belts of the Western Cordillera, including the Yukon (fiom Gabrielse et al., 199 1). YUKON TERRANES AND MINERAL DEPOSl
o Au Au (*Ag,*Cu,*Pb,*Zn,kMo) 1. Mcl 38. Gut + Ag (*Qb,*Zn,*Cu,*Au) 2. McMillun 39, Craig CRATON 3. Iiylimd Gold 40, vcra Pb-Zn (*Ag,*Au,*Cu,*Ba) 4. Sa Ikna lies 41. Val Platforms Cu (*Mo,*Au,*Ag,*Pb,*Zn 5. Uailey 42. Marg 6 Iim 43. Clark IlSelwyn Basin v NI-CU 7. Logtung 44. Dublin Gulch 8. Lugan 45. Gmr(Ray Ciulch) Coal 9. JC - 46. Paglstecl 10. Rcd TERRANES Mouninin 47. Ukndz + Iron I I. Marlin 48. Marallton (Airstrip) 12. Venus Cassiar t b = barite, 49. Pale ( Wrdc) 13. Skukum 50.51. GllrlicIllfyd Ring Yukon-Tanana t = tungsten, 14. Gddrll I] IS. Mi.kid m = moly (b~etPlum Coal) W (SkJum Creck) 52. Pan Ow I]Iisiing 16. Whi lehorsc Copper r = rhodontte (West Illtyd) 17. KcVa 53. Dalaurier Slide Mountain 1 =i& 18. Rishy 54. Sy#oefip 19. WhiSty Lake 55. Crest s = tin 20. 'lintha (Eagle) Cache Creek t 56. Wctlgnrn 21. Wolf 57. Canalask 22. Wolverine I-ake 58. Division 23. Kud~% Kayah 59. Williams Crork 24. Fyn: 60. Minto/ k.f 25. ICC 61. Tmullus 26. King Arctic 62. Lafm 27. Alexander Matt tkn-y 63. Bmwn-McUadc 28. tiowards Pass 64. Mount Nanwn 29. (ircw Creek Wrangellia (Webb, tiucstis, 30. Pam, (irum, Vatigt~dn, Swim Flex) Grizzly (DY ), 45. Antoniuk Chugach 3 1. CICM Ide 66. Casino 32. Ijnitai Kmllill 67. Zew Undivided 33. Turn 68. llai River metarnorphics 34. Jason 69. Mam 35. Mwwg 70. B~wcryCreek 36. Samovar ('l'ca) 7 1. Boundary 37. Pladlnca
Figure 2.2: Location of temeassemblages and selected mineral deposits within Yukon Territory (modified from Wheeler et al., 1991 and Yukon Minfile). ranging in age fiom Upper Paleozoic to Mesozoic (Coney et al., 1980; Irving and Wynne,
1992).
Two major northwest-trending strike-slip faults known as the Tintina and Denali
faults slice southern Yukon into three main sections. During Late Cretaceous-Tertiary
the, the Tintina Fault had undergone approximately 450 krn of dextral slip, while the
Denali Fault underwent approximately 250 km of dextral slip (Templeman-Kluit, 198 1).
2.2 Local Geology and Metallogeny
The geology of the Dublin Gulch-Mayo area consists predominantly of highly
deformed Upper Proterozoic to Mississippian Hyland Group clastic rocks of the Selwyn
Basin (figure 2.3). Grit, quartzites and phyllites that form thrust sheets of regional extent dominate these clastic rocks. Thrusting was initiated during Middle Cretaceous time as a result of arc-continent collision along the continental margin to the southwest
(Templeman-Kluit, 1979). Thrusting at this time caused the juxtaposition of Selwyn basin clastic rocks against similar-aged. carbonate-dominated, strata of the Mackenzie
Platform to the north (Hitchins and Orssich, 1995). Subsequent to deformation, the clastic rocks were intruded by stocks and dykes of quartz monzonite to granodiorite composition of Cretaceous age (Srnit et al., 1995). Several of the quartz rnonzonite intrusions in the Mayo map area have been dated by K-Ar, which yielded dates between
89 Ma and 97 Ma (Hunt and Roddick, 1987; Stevens et al., 1981,1982).
The Dublin Gulch property encompasses the largest known lode source to the placer deposits within the Haggart Creek drainage system. The Dublin Gulch property contains several mappable stocks, dikes and sills of Cretaceous granodiorite to granite,
which have intruded the foliated sequence of quartzite and phyliite. The Dublin Gulch
stock, the largest stock on the property, is a medium-grained phaneritic granodiorite body
dated at 92.8 k 0.5 Ma (Smit et al., 1995). The stock has a width of up to 2 km and a
length of 5.5 km and is elongated in the direction 070" (figure 2.4) (Smit et al., 1995).
Developed around the stock, is a contact aureole of andalusite and biotite homfels (Smit
et al., 1995). Other intrusive bodies occur west of Haggart Creek, however these bodies
are much smaller in area and are only weakly mineralized (figure 2.3). These bodies are
predominantly dikes and sills of granodiorite to quartz monzonite composition; no quartz-
gold veins were observed in any of the intrusions (Hitchins and Orssich, 1995).
Other potential bedrock sources to the placer gold in the area occur in quartz-sulphide
fissure veins of local extent. The quartz-sulphide fissure veins occur within a 12 km by 2
km area extending from 6 km west of Haggart Creek to Potato hills in the east (figure 2.4)
(Hitchins and Orssich, 1995). Although explored primarily for silver, the Rex and Peso
veins west of Haggart Creek contain up to 0.1 g/t and 1.8 g/t Au respectively (Hitchins
and Orssich, 1995). Quartz-sulphide veins are also observed between Haggart Creek and
Potato Hills and appear to be spatially related to the northern contact of the Dublin Gulch stock. Veins east of Haggart Creek contain much higher gold values than those veins found west of Haggart Creek. East of Haggart Creek, quartz-sulphide veins with grades up to 14 dtare common (Hitchins and Orssich, 1995).
Other mineral deposits within the area include the Rex and Peso No. 1 Ag-Pb-(-Sb-
As) veins; these occur 5 km to 7 km southwest of Dublin Gulch. In 1943, cassiterite was found in local placer deposits and was eventually traced to its source above Ann Gulch on MESOZOIC Anmopyrrtsscorodtle-gold vdrns...... CRETACEOUS C~~lhlltb.t~~r~dIi~~vrrns and lodes...... sn/ Granod~orrte.granite and allted rocks Tungsten lodes (scneelitem Sham; woltramite In ouanr veins) ...... W X MolyDUenrte occurrence...... Mo% PRECAMBRIAN ANOIOA PALEOZOIC Placer (gold)...... YUUON GROUP ....- ...... Placer (scnselrte) ...... -.*. ..a. Ouartr~te,Rhyllile. grapftrtic schist, quarn- Bedding (rnclined) ...... J ~ICBscntst. ~imestone,sham Contours (interval100 1ll ......
Figure 2.4: General geology and mineral deposits of Dublin Gulch area, Haggiwt Creek drainage basin (from Boyle, 1979). Tin Dome, directly north of Dublin Gulch (figure 2.4). Finally, tungsten lodes occur as scheelite in skam and wolfiarnite in quartz veins within the Dublin Gulch stock; scheelite forms a number of local placer deposits (figure 2.4) (Boyle, 1979). CHAPTER 3 - PHYSIOGRAPHIC SETTING AND GLACIAL HISTORY
3.1 Physiography of Yukon
Physiographic divisions of Yukon are shown in figure 3.1. Yukon Temtory,
specifically southern Yukon, is dominated by summits, ridges and upland plateaus, which
define surfaces of low relief between 1000 and 3000 metres above sea level. These
surfaces have a long history of modem stream and glacial erosion and although some
large uplands remain relatively unaltered, other areas are deeply incised and dissected
with only isolated peaks remaining (Templeman-Kluit, 1980).
The south central Yukon Territory is defmed as that region south of the Ogilvie
and Wemecke mountains. It is bounded to the northeast by the Selwyn Mountains, and to
the southwest by the St. Elias and Coast mountains (Templeman-Kluit, 1980). This
region is dominated by the Yukon Plateau, a broad lowland surface, which ranges
between 1000 and 2000 metres in elevation. In central Yukon, the Yukon Plateau
includes the Lewes, Klondike, Macmillan and Stewart plateaus (Templeman-Kluit,
1980). Contained within the Yukon Plateau are two northwest-southeast trending valleys
known as the Tintina and Shakwak trenches; these trenches are largely controlled by the
Tintina and Denali faults, respectively. The St. Elias Mountains, to the southwest, contain some of the highest peaks in Canada, rising to approximately 5900 metres.
Continual uplift of these mountains in the last 30 Ma resulted in a decrease of warm, moist, Pacific air penetrating the interior of Yukon. This produced an increasing rain shadow effect which resulted in successive glacial events becoming less extensive over time (Armentrout, 1983). Mms. Old Crow i Scale North
bfoun tains
Stcwan Platmu Klondikc Plntau
Nath Platmu
Lcwes Plateau
Pelly Mountains
HyhdHighland
Figure 3.1 : Physiographic subdivisions of Yukon Territory; note location of Haggart Creek study area (modified from Bond, 1997~). Southern Yukon is dominated by the Kaska mountains, which can be further
subdivided into the Pelly (north) and Cassiar (south) mountains. The Pelly and Cassiar
mountains are elevated zones within the generally lowiand of the Yukon Plateau. The
Selwyn mountains are located in eastern Yukon, just west of the continental divide. The
Selwyn and Kaska mountains are separated from the northern Rocky mountains by the
Liard Lowland, a broad, structurally controlled intermontane lowland (Jackson and
Harington, 199 1). The Mackenzie mountains are located east of the continental divide.
Northern Yukon (that is, north of the Ogilvie and Wemecke Mountains) has not
been extensively glaciated. This area contains a broad lowland known as the Old Crow
Basin, which rises to the east into the Richardson Mountains.
3.2 Local Physiography
Haggart Creek and its tributaries are located in the northern portion of the Stewart
Plateau physiographic subdivision, just south of the Ogilvie Mountains, central Yukon
(see figure 3.1 ). Broad, rolling hills of moderate relief characterize the area. The region
is defined by moderate elevations ranging from approximately 760 metres above sea level
(a.s.1.) in valley bottoms, to approximately 1520 metres a.s.1. on uplands. Local uplands
are represented by Haggart Dome, Lynx Dome, and Potato Hills and are the only areas in this region which are above treeline. Upland areas generally coincide with resistant rock types such as local felsic intrusions found on Potato Hills.
The major drainages in the area are Haggart Creek and Lynx Creek. Haggart
Creek trends north-south, while Lynx Creek trends generally southwest. Haggart Creek may be divided into upper and lower reaches. Lower Haggart Creek is morphologically an extension of Lynx Creek (see figure 3.2 in pocket) and occupies a very large, broad, U-
shaped glacial valley. Upper Haggart Creek. having been less extensively glaciated, has a
much narrower U-shaped glacial valley. Tributaries such as Dublin Gulch. Gill Gulch
and Fisher Gulch are all transverse to the main regional ice flow direction (see figure 3.2
in pocket); thus glacial scour of the last glaciation (Reid) had little affect on these valleys.
As a result, these tributary valleys remain narrow and V-shaped with steep valley sides.
3.3 Climate
The climate of Yukon has been classified as sub-Arctic continental (Jackson and
Harington, 199 1) and is characterized by long, cold winters, followed by short. mild
summers. The mean annual temperature ranges from approximately -2OC in the south. to
approximately -lO°C in the nonh. January is the coldest month of the year. with mean
monthly temperatures ranging from -25OC to -35°C.whereas July, the warmest month,
has mean monthly temperatures ranging from 13OC to I6'C (Jackson and Harington.
199 1 ). Permafrost is common and widespread in the area. Annual precipitation values
may vary within Yukon. however two distinct wet zones exist. One zone within the St.
Elias Mountains may have total annual precipitation values exceeding 2000 mm in divide areas. The second zone is coincident with divides in the Cassiar. Pelly and Selwyn
Mountains with annual precipitation values which may exceed 700 mm (Jackson and
Harington, 1991). 3.4 Permafrost, Soils and Vegetation
Yukon Territory includes three types of permafrost distribution, namely
continuous, widespread and scattered permahst (figure 3.3)(Heginbottom, et al., 1995).
Regional permafrost distribution is controlled by mean annual temperature, in
conjunction with mean annual precipitation, whereas local permafrost variations are
controlled by surface sediments, soil moisture, aspect and snow depth (Burn,1987). The
Mayo area and Haggart Creek drainage system lie within the zone of extensive
discontinuous permafrost (see figure 3.3), in which 50090% of the land area is underlain
by permafrost. Within this area, permafkost is typically found on north- and east-facing
slopes, highlands above approximately 1370 m elevation, and poorly drained valley
bottoms. Coarse deposits such as glacial outwash terraces are generally well-drained, dry
and ice-free, whereas fine grained deposits such as organic-rich silt deposits are more
likely to contain ice.
A brunisolic soil, also referred to as the Stewart neosol (Tarnocai et al., 1985), is the most dominant soil type within the study area. Brunisols are defmed as poor to well drained, yellowish-brown mineral soils that develop in forest, alpine and tundra settings.
Temperature regimes for brunisols range from ternperate/cool to arctic, while moisture regimes conducive to bnvlisol development are generally perhumid to semi-arid (Clayton et al., 1977). The soil profile ranges in thickness from 37 to 49 cm; it contains limited pedogenesis weathering and little to no illuviated clay or other soil structures (Tarnocai, et al., 1985). Other soil types found in the Mayo area are cryosols and fibrisols. Cryosols occur where pemafkost is prevalent, whereas fibrisols occur as thick, organic-rich? weakly decomposed soils in poorly drained areas (Clayton et al., 1977). IsoIated Patches
Figure 3.3: Permafrost distribution, Yukon Territory (from Heginbottom et al., 1995). The study area lies within the northern boreal forest of the Mayo Lake-Ross River
ecoregion (Oswald and Senyk, 1977). A northern mixed deciduous and coniferous forest
dominates the area, however vegetation varies locally according to slope, aspect and
surficial deposits. North-facing slopes are characterized by black spruce (Picea
mariano), paper birch (Betulapap-vrfera), willow (Salix sp.) and aider (Alnur crispa).
Well-drained south-facing slopes in valley bottoms contain a mix of white spruce (Piceu
glauca), aspen (Populus tremuloides) and various grasses, whereas south-facing slopes on
plateaus and mountains have a more dense tree growth and are dominated by white
spruce, paper birch, aspen and grasses. Mountain alder, willow and white spruce are
common along local drainages.
Large, glacial, U-shaped valleys host a variety of surficial deposits, resulting in
diverse vegetation. Black spruce, sedges and sphagnum tussocks are found on poorly
drained alluvium such as glacio-lacustrine sediment. Well-drained areas in valley
bottoms such as alluvial and glacial terraces are host to white spruce, aspen, paper birch, and less commonly, lodgepole pine (Pinus contorfa). Subalpine regions are dominated by a mix of subalpine fr (Abies Zasiocarpa), dwarf birch (Betula nuna L.), willows and mosses. Alpine regions contain ericaceous shrubs, willows, dwarf birch, lichens and mosses. The fmt species to occupy disturbed sites are fueweed (Epilobium angustfolium) and willow species.
3.5 Regional Glacial History
The southern and central parts of Yukon Territory have been extensively glaciated throughout Pleistocene time. The glaciations were initiated by the expansion of alpine glaciers during periods of global climatic cooling. These alpine glaciers hrther
developed into piedmont systems, which coalesced to form major ice sheets. The flow of
these ice sheets was mainly controlled by topography and flowed towards central Yukon.
The Cordilleran ice sheet, the most extensive of these ice sheets which developed in
Yukon Temtory, radiated from ice-divides in the Ogilvie, Wernecke, Selwyn, Pelly,
Cassiar and Eastern Coast Mountains, and was adjacent to a piedmont glacier complex
from the St. Elias Mountains (Jackson et ai., 1996). Along the peripheries of the
Cordilleran ice sheet, local montane glacier events have been documented in the
Mackenzie Mountains, Northwest Territories (Duk-Rodkin et al., 1996; Barendregt et a!.,
1996), the Southern Ogilvie Mountains (Vernon and Hughes, 1966; Duk-Rodkin, 1995-
1996) and in isolated uplands on the Yukon Plateau (pers. cornrn. 1999, Jeffrey Bond).
Multiple glacial episodes have affected Yukon, with each advance becoming progressively less extensive. The pre-Reid includes undifferentiated multiple glaciations, with the earliest episode recorded at >2.58 Ma (Froese, 1997). The well-defmed Reid
(approximately 300 000 years ago) and McConnelI (approximately 29 000 years ago) glaciations represent the iast two glacial episodes. Glacial l hits of the pre-Reid, Reid, and Mccomell glaciations are shown in figure 1.1. The interglacial periods which separate these glacials, are represented by well preserved paleosols. The Wounded
Moose paleosol developed prior to the Reid glacial event, while the interglacial period between the Reid and Mccomell (Koy-Yukon interglacial) produced the Diversion
Creek paleosol (Tarnocai et aL, 1985). The Stewart neosol is the Holocene soil developed since the termination of the McConnell glaciation (Tarnocai et al., 1985). 3.6 Local Glacial History
Haggart Creek study area lies within the limits of the pre-Reid and Reid
glaciations and immediately outside the McConnell glacial limit (figure 3.2, in pocket);
pre-Reid ice sheets have glaciated the entire study area. Evidence of pre-Reid Cordilleran
ice is limited to scattered erratics above the Reid glacial limit. Pre-Reid erratics have
been documented on Haggart Dome and Potato Hills at an elevation of approximately
4900 feet (Bond, 1997b).
The Reid glaciation represents the last Pleistocene ice sheet to have glaciated the
study area Based on current drainage patterns and McComell glacial limits, it is
presumed that Reid ice entered Haggart Creek drainage fiom Lynx Creek. Ice in the
South McQuesten River valley spilled over the divide into Lynx Creek and eventually
advanced down lower Haggart Creek (figure 3.2, in pocket). Lynx and lower Haggart
creek valleys were the main conduits for Reid ice advancing through the study area; this
is emphasized by the U-shaped morphology of each of these valleys. Lynx Creek glacier
advanced down lower Haggart Creek and eventually back into the South McQuesten
River valley. At this time, ice also spilled into, and advanced up upper Haggart Creek,
breaching the divide into Christie Creek and meeting ice fiom the East McQuesten River
drainage (figure 3.2, in pocket) (Bond, 1997b). Reid ice attained elevations of 3600 feet
a.s.1. in the study area based on the upper limit of Reid erratics on Potato Hills (Bond,
1997b). The orientation of upper Haggart Creek valley is transverse to local ice-flow
patterns. Therefore, ice that spilled into Haggart Creek valley fiom Lynx Creek valley would have been stagnant ice with little erosive power, since the ice would have been advancing up-valley, that is, up-gradient. The McConnelI glaciation terminated in Lynx Creek approximately 1 1 kilometres east of the confluence between Lynx Creek and Haggart Creek (figure 3.2, in pocket).
No part of Haggart Creek was directly affected by McConnell ice. Mccomell outwash flowed down Lynx and lower Haggart creeks (Bond, 1997b).
3.7 Local Surficial Geology
The study area is characterized by colluvium covered uplands, with minor exposed bedrock on plateau summits, ridges, and locally in gulches. A colluviated Reid till veneer was mapped by Bond (1997b) between 2800 and 3600 feet a.s.1. on the left- limit of Haggart Creek near the mouth of Lynx Creek (Bond, 1997b). Remnant Reid terraces are present at the confluence of Haggart and Lynx creeks and can be traced into upper Haggart Creek along the left-limit. This terrace is exposed as a till blanket in a mining cut near the mouth of Dublin Gulch (figure 3.4). The Reid terrace can be traced down the right-limit of lower Haggart Creek to the mouth of Secret Creek. McConnell periglacial fans originate from dl major tributaries in Haggart creek. In Lynx Creek, periglacial fans coalesce to form an apron of sediment on the flanks of the valley.
Colluvial aprons are present between the tributary fans in Haggart and Lynx creek valleys. Modem alluvium lines the floodplains of major streams. Figure 3.4: Reid terrace exposed as a till blanket in a mining cut near the mouth of Dublin Gulch. Exposed section is approximately 1 2.5 meters thick. CHAPTER 4 - ME:THODOLOGY
4.1 Introduction
Reconnaissance of the study area was undertaken during August of 1996;
fieldwork was completed between June and September 1997. This thesis is part of an
ongoing study of the placer potential of the Mayo Mining District, funded primarily by
the Yukon Geoscience Program, Yukon Temtory. The primary method employed in this
study was sedimentology and stratigraphy. Samples were collected from representative units for grain-size analysis, heavy-mineral analysis, palynology and Carbon- 14 dating.
4.2 Sedimentology
Approximately 35 sites were visited in the study area, of these, 28 sites were the subject of detailed sedirnentologic analysis (see figure 4.1 and table 4.1). Exposures were measured on a bed-by-bed basis. Sedimentological descriptions for each unit included the following:
bed variation or range texture primary sedimentary structures (sorting, stratification, grading, etc.) secondary sedimentary structures (loading/faulting, staining, alteration, etc.) nature of basal contact (sharp, gradational, interfingering) roundness, angularity and lithology of clasts alignment or imbrication of clasts colour md cohesiveness of sediment accessories (presence of organics, fossils, cryogenic features such as ice-wedge casts and placer gold)
Table 4.1
Section locations for Haggart Creek study area.
Section Creek Elev. (ft.) Lat. Long. East. North. LW-97-0 1 Haggart, Left-limit 2500 64'00'55" 135'50'53" 458525 7098900 LW-97-02 Haggart, Left-limit 2475 64'00'48" 135'50'53" 458525 7098700 LW-97-03 Haggart, Left-limit 2485 64'00'5 1" 135°50Y3" 458525 7098800 LW-97-04 Haggart, Left-limit 2450 64'00'43" 135'50'53" 358425 7098525 LW-97-05 Haggart, Left-limit 2450 64'00'42" 135'50'53" 458525 7098500 LW-97-06 Haggart, Left-limit 2480 64'00'49'' 135'50'53" 458525 7098725 LW-97-08 Haggart, Left-limit 2540 64'00'57" 135'50'53" 458525 7098950
LW-97- 15 Haggart, Left-limit 2545 64'0 1'0 1" I 35'50'53" 458525 7099 100 LW-97-24 Haggart, Right-limit 2435 64'00'32" 135O5 1'1 1" 458250 7098225 LW-97-25 Haggart, Right-limit 2420 64°00'32" 135'5 1'1 1" 458250 7098225 LW-97-26 Haggart, Right-limit 2400 64'00'26" 135'5 1'1 1" 458250 7098050 LW-97-27 Haggart, Right-limit 2400 64°00'26" 135'5 1'1 1" 458250 7098050 L W-97-09 GiH Gulch 2530 64°01'41" 135O5 1'15" 458200 7100275 1 GillGulch Gill Gulch Gill Gulch Gill Gulch Gill Gulch Gill Gulch Gill Gulch 2500 64'01'4 1" 135'5 1'15" 458200 7 100275 FisherGulch 2800 64'02'24'1 1131°51'04" 457521 7101625 I I I I ( 1 Fisher Gulch Dublin Gulch Dublin Gulch Dublin Gulch Dublin Guich Dublin Gulch Dublin Gulch 4.3 Sampling Procedures
Nineteen bulk gravel samples were collected during the 1997 field season. Only those samples believed to contain gold and/or other heavy minerals were collected for analysis; a few diamict samples were collected for comparative grain-size analysis.
Sampled areas were scraped using a shovel to remove any surface debris and to avoid contamination. The shovel was cleaned and then used to obtain approximately 2-5 kg of bulk gravel sample. Selected samples were panned on site to document any presence of gold, while most samples were collected for grain-size and heavy-mineral analysis.
Grain-size samples were dried, split to 1- 1.5 kg samples and sieved through M, # 10, # 1 8,
#35, #60, it120 and #230 Tyler mesh screens. After weighing, the #18 to #I20 fractions were recombined and sent for heavy-mineral analysis.
Eight organic samples were collected for C- 14 dating. Wood was sampled wherever possible to avoid any root contamination, which may commonly occur when sampling bulk organic-rich soil samples. CHAPTER 5 - SEDIMENTARY FACIES AND FACIES ASSOCIATIONS
5.1 Introduction
The first step in identifying sedimentary environments and reconstructing
paleoenvironrnent is determining which facies exist. A sedimentary environment consists
of a particular group of physical, chemical and biological parameters, which combine to
produce a body of sediment characterized by specific textural, structural and
compositionaL properties; these bodies of sediment are termed facies (Boggs, 1987;
Walker, 1984 and 1992). Facies can be further combined to produce facies associations.
Facies associations are groups of facies that occur together and are genetically or
environmentally related (Reading, 1986; Walker, 1984 and 1992).
A total of 13 hies were identified in the study area. Alluvial facies are described
by using a modification of Miall's summary facies code (1982). This system uses two
letten, whereby the first letter represents the ciast size, while the second letter represents
sedimentary structure. Eyles et al. (1983) further enhanced this scheme by introducing
codes for diarnict facies; these codes will also be used in this discussion. Table 5.1 is a
summary of listed facies and facies associations.
5.2 Sedimentary Facies Descriptions
5.2.1 Facies 1: Massive to crudely bedded gravel (Gm)
Facies Gm is by far the most abundant facies in the study area and ranges in thickness between 0.2 m and 6.0 m. The gravel is ciast-supported and matrix-filled, with matrix being composed of clay to granule size particles (figure 5.1). Clast size ranges hmpebble to boulder, with cobble-sized ciasts being most abundant. Clasts are Figure 5.1 : Weakly imbricated, clast supported, pebble-cobble gravel (Facies Gm)on right-limit ofHaggart Creek. Flow is from left to right. Rock hammer measures 30 cm. typically subangular to rounded; however some units contain highly angular clasts.
Clasts may or may not be imbricated, with a-axis (long) transverse to paleoflow. Weak,
large-scale crossbedding defined by clast imbrication may also be present.
The formation of massive to crudely stratified gravel is poorly understood;
however, several authors have made suggestions concerning their development. Facies
Grn predominates in areas of proximal braided rivers of paraglacial environments, as well
as in braided rivers not influenced by melting ice. The dominance of facies Gm reflects
the low ratio of mean particle size to water depth, which is a function of the relatively low
relief of bars and channels in proximal reaches (Rust and Koster, 1984). Hein and
Walker (1 977) suggest that in proximal reaches, the high rate of discharge of coarse gravel will result in a crude horizontal stratification with imbrication. Bars within upstream reaches form initially as lag deposits; these form at maximum flow stages as a diffbse gravel sheet a few pebble diameters in thickness. If water and sediment discharge is high, the diffise gravel sheet would not have time to aggrade vertically and no angle- of-repose slip face would develop. The resultant deposit would be massive, or display low-angle stratification inclined downstream (Hein and Walker, 1977). Similarly,
Leopold and Wolman (1957) proposed that longitudinal bars begin as a nucleus of the coarsest bedload fractions deposited in mid-channel as flow diminishes, and grows by the addition of finer sediment downstream from the nucleus.
5.2.2 Facies 2: Crudely graded, horizontally stratified gravel (Gh)
Facies 2 (Gh) is similar to Facies 1 (Gm), however facies Gh may display crude normal grading (figure 5.2). Facies Gh is a poorly-sorted, clast-supported, matrix-filled gravel, with thickness ranging between 0.2 m and 3.65 m. Clasts range from pebble to Figure 5.2: Massive to crudely graded, poorly sorted gravel (Facies Gh) from Fisher Gulch; trowel is approximately 20 cm long. boulder size, with cobble sized clasts as the most common clast size; matrix is comprised
of clay to grit size particles. Clasts are typically angular to subangular. Facies Gh may
display weak a-axis (long) imbrication transverse to paleoflow; however, a disorganized
fabric is not uncommon.
The presence of boulders and poor sorting of facies Gh indicates high energy
flows with rapid deposition. Massive, poorly-sorted sediments with disorganized fabric
and gradational bed contacts are typical of debris flows or hyperconcentrated flood flows
(Levson, 1992; Morison and Hein, 1987). Morison and Hein (1 987) interpret these flows
to be initiated by high seasonal runoff on unstable, weathered slopes. Normal grading is
believed to develop as denser particles settle directly from the dispersion or suspension
during more fluid phases of sedimentation.
5.23 Facies 3: Stratified gravel with planar tabular crossbeds (Gp)
Facies Gp is a moderately to well-sorted, pebble gravel with planar tabular crossbeds. Units of this facies typically have a non-scoured base and reach a maximum thickness of approximately 2 m. Individual beds are between 5 and 30 crn thick and are defined by a change in grain-size, or a change from matrix-filled to openwork gravel.
The average dip on foresets is 20°. Clasts are subrounded to well rounded. Clasts are predominantly pebble sized, however minor cobbles may be present.
Hein and Walker (1977) and Morison and Hein (1987) suggest the development of planar tabular crossbedded gravel in downstream reaches of streams and rivers. In downstream reaches, where sediment discharge is lower, there is time for the gravel lag to aggrade vertically and an angle-of-repose slip face would develop. Therefore, the planar tabular crossbeds are interpreted as being deposited by the downstream progradation of
high relief barforms, with angle-of-repose foresets.
5.2.4 Facies 4: Stratified gravel with trough crossbeds (Gt)
Facies Gt is a moderately to well-sorted, matrix-filled, pebble-cobble gravel with
trough crossbeds (figure 5.3). This facies typically has a scoured base and reaches a
maximum thickness of approximately 2 m. Clasts are subrounded to well rounded and
matrix is predominantly fine sand to very coarse sand.
Crossbedding in the gravel indicates bedload transport. Trough crossbedded
gravel has been interpreted by Miall (1 992) as minor channel fills and represents the
secondary infilling of channel scours by traction current bedload. Hein and Walker
( 1977) attribute the trough crossbedded gravel to the progradation of gravelly 3-Ddune
bedforms.
5.2.5 Facies 5: Horizontally laminated sand, and pebbly sand (Sh)
Facies Sh is composed of horizontally laminated, moderately to well-sorted sands
and pebbly sands (figure 5.4). Facies Sh commonly occurs as discontinous lenses within
facies Gm. Facies Sh has an average thickness between 5 and 20 cm,and reaches a
maximum thickness of 55 cm. Mia11 (1 992) suggests the deposition of facies Sh by
planar bed flow in an upper flow regime.
5.2.6 Facies 6 and 7: Crossbedded sand and pebbly sand (Sp and St)
Facies 6 (Sp) and facies 7 (St) consist of moderately to well-sorted, crossbedded
sand and pebbly sand. Facies Sp reaches a maximum thickness of 1.5 m, while the average thickness of facies St ranges between 5 cm and 20 cm. Facies Sp, having planar tabular crossbeds, likely formed as a result of active foreset migration of bar fkonts Figure 5.3: Moderately to well-sorted, matrix-filled, pebble-cobble gravel with trough crossbeds from left-limit oMaggart Creek. Spacing between flagging is 1 m. Figure 5.4: Moderateiy to well sorted, horizontally laminated sand (Facies Sh) within crudely stratified gravel (Facies Gm)from Dublin Gulch. Lens cap is 6 cm in diameter. in downstream reaches (figure 5.5). Facies St is commonly found as discontinuous lenses
or wedges within gravel facies. Facies St, having trough crossbeds, is believed to have
been deposited as shallow infillings of gravel bedforms.
5.2.7 Facies 8: Sand, very fine to very coarse with ripple marks (Sr)
Facies Sr is very rare, with only one occurrence noted within the study area.
Facies Sr is found in a 20 cm thick unit, which is in gradational contact with facies Gm.
Facies Sr is interpreted to have developed as a bar top sand, which was deposited during
low water episodes as in the waning stages of a flood.
5.2.8 Facies 9: Sand, silt and mud with fme laminations (FI)
Facies Fl is composed of poorly-sorted to well-sorted, sand, silt and mud with fine
laminations (figure 5.6). Facies FI generally occurs as discontinuous lenses and beds, which range in thickness between 15 cm and 80 cm. This facies forms discontinuous lenses and beds due to secondary features such as frost wedging and cryoturbation (figure
5.7). Silt may be organic rich and the presence of small woody debris (c 2 cm) is not uncommon. Small cut-and-fill structures of grit form lenses 10-30 cm wide and 2-5 cm thick within this facies and suggest a fluvial origin.
In areas where this facies forms relatively continuous beds with distinct laminae, is moderately to well-sorted, and contains few pebbles and cobbles, this facies is interpreted to represent overbank, or waning flood deposits. In areas where F1 does not form laterally continuous beds, where sorting is relatively poor, and where cut-and-fill structures of grit are abundant, this facies is believed to have formed as a result of small fme-grained alluvial and colluvial fans possibly derived fkom seasonal surface run-off, or meltwater (Froese, 1997). Figure 5.5: Interbedded facies of planar crossbedded sand and pebbly sand (Sp) with planar tabular cross-bedded gravel (Gp) from right-limit of Haggart Creek. Dip on forsets is approximately 20 degrees ;flow is from right to left on photograph. Pogo measures 1.5 m. Figure 5.6: Discontinuous lenses of laminated fine sand and silt (Facies FI) within heavily cryoturbated pebbly diamict (Facies Dms)from Gill Gulch. Pen measures 15 cm. Figure 5.7: Ice wedge cast cuts organic-rich, laminated silt and fine sand (Facies F1) and pebbly diamict (Dms) from Gill Gulch. Whole unit is heavily reworked due to cryoturbation. Pen measures 15 cm. 5.2.9 Facies 10: massive silt (Fm)
Only one occurrence of facies Fm was noted in the study area. Facies Fm is
composed of buff-coloured, homogeneous, non-stratified, coarse silt (figure 5.8). Facies
Fm is well-sorted, and forms discontinuous beds, which reach a maximum thickness of
50 cm; these beds are in gradational contact with underlying horizontally stratified gravel
(facies Gh). In some areas, ventifacts (pebbles faceted by the abrasive action of
windblown sand and dust) were found at the contact between facies Fm and the
underlying gravel of facies Gh. The discontinuity of the beds of facies Fm are likely due
to reworking from overlying colluvial deposits. The homogeneity and grain-size of this
facies, along with the presence of ventifacts suggests a windblown origin for these
sediments. Facies Fm is interpreted to represent an aeolian deposit of windblown loess.
5.2.10 Facies 11 : Organics and organic-rich silt (Fo)
Facies Fo represents organic-rich silt, as well as organic units comprised of peaty
material, plant material, or woody debris. Peaty facies Fo are rich brown to black in
colour and are typically thin, reaching a maximum thickness of approximately 20 cm.
Facies Fo is believed to represent a buried soil (paleosoi) when peaty and rich with
woody debris and other organics. Another variation of facies Fo is closely associated with facies FI, whereby facies F1 grades into a more massive, chocolate-brown, organic- rich silt (facies Fo). In this case, facies Fo likely represents a transported soil that has been reworked into a colluvial deposit. Figure 5.8: Massive, buff-coloured medium to coarse silt (Facies Fm)overlying weakly stratified and crudely graded gravel (Facies Gh) from Gill Gulch. Lens cap is 6 cm in diameter. 5.2.1 2 Facies 12: Massive to weakly stratified, matrix-supported gravel diamict
(Dms)
Facies Dms is common in the study area and occurs as a very poorly-sorted,
massive diamict, as well as a poorly-sorted, weakly stratified diarnict. The term diamict
has been defmed by Eyies and Kocsis (1 988) as "any poorly-sorted admixture of gravel,
sand and mud regardless of depositional setting". The more massive diamict (Drns)
occurs as a matrix-supported, pebble-cobble diamict with highly angular to subangular
clasts. Organic material such as woody debris and rip-up clasts of organic-rich silt may
be present (figure 5.9). This form of Facies Drns often occurs as basal units to alluvial
fan sequences. Poor sorting, the degree of angularity of the clasts and the presence of rip-
up clasts suggests a debris flow origin for this facies.
The weakly stratified form of facies Drns is a poorly-sorted, matrix-supported,
fmer grained pebble diamict (cobbles are rare) (figure 5.10). Clasts are predominantly
angular to subrounded and commonly show a-axis alignment parallel to slope. Organics
are common, however usually occur as small (< 2 cm) broken pieces of woody debris.
This facies forms continuous units that may be traced laterally for several metres and
commonly blankets most of the exposed sections. All the above characteristics suggest a colluvial origin for this facies.
5.2.13 Facies 13: Massive, matrix-supported gravel diamict (Dmm)
Facies Dmrn is a highly competent, massive, matrix-supported gravel diamict
(figure 5.1 1). CIast size ranges from pebble to boulder sized clasts. Clasts are typically subangular to well-rounded; boulders may be striated. Matrix is predominantly silt and clay with lesser amounts of sand-sized particles. A distinct clast orientation, with a-axis Figure 5.9: Massive, very poorly sorted, matrix-supported, pebble-cobble diamict (Facies Dms) from Gill Gulch. Note large piece of woody debris and ripup clasts of organic-rich silt (see mows). Lens cap is 6 cm in diameter. Figure 5.10: Weakly stratified, poorly sorted, matrix- supported, pebble diamict (Facies Dms) from left-limit of Haggart Creek. Note a-axis alignment of clasts parallel to slope (above pen). Pen measures 1 5 cm. Figure 5.11 : Highly competent, massive, matrix-supported, gravel diamict (Facies Dmm) from left-limit omaggart Creek. Width of shovel handle measures 4 cm. (long) parallel to paleoflow may be present. The colour is light grey to buff Lower contacts of units of facies Dmm are erosional.
The presence of a wide variety of clast sizes, striated clasts, massive character, fabric, and erosional basal contacts suggests a basal till as the origin for facies Drnm.
Where a well-developed fabric is not present, facies Dm11 is interpreted to be a resedimented till.
5.3 Facies Associations
5.3.1 Facies Association 1: Proximal braided stream to alluvial fan (Facies Gin, Gh and Dms)
Proximal braided streams to alluvial fan environments (facies association 1) are dominated by poorly-sorted, crudely stratified gravel (facies Gm), horizontally stratified and crudely graded gravel (facies Gh) and massive to weakly stratified gravel diamicts
(facies Drns, debris flows) (Miall, 1982; Morison and Hein. 1987). During interglacial times, long periods of erosion resulted in deeply weathered bedrock. In high relief areas such as Haggart Creek drainage basin, slope failures were common, which resulted in weathered bedrock being carried downslope as debris flows on alluvial fans. During pre- and post-glacial times, slopes would have become increasingly unstable with a lack of vegetation, resulting in the overloading of streams with sediment. Sediment would have been carried downstream as diffise gravel sheets of poorly-sorted, crudely stratified gravel, with minor amounts of horizontally stratified to trough crossbedded sands (facies
Sh and St respectively). 5.3.2 Facies Association 2: Medial to distal braided stream (Facies Gm, Gp, Gt, Sp,
St, Sr and Sh)
Medial to distal braided stream environments (facies association 2) are
characterized by coarse gravel facies Gm,Gp, and Gt in association with fmer sand facies
of Sp, St, Sr and Sh. In midstream and downstream reaches, the rate of sediment
discharge is slower, resulting in vertical bar growth and deposition of crossbedded gravel
(Hein and Walker, 1977; Miall 1982). Within these reaches, transverse and diagonal bars
are abundant, resulting in planar tabular crossbedded gravel (Gp) and trough crossbedded gravel (Gt). In more distal settings, there is a substantial decrease in grain-size, resulting
in the deposition of sandy facies Sp, St, Sr and Sh (Hein and Walker, 1977).
5.35 Facies Association 3: Wandering gravel bed river (Facies Gm, Sp, St and Sh)
Within the study area, wandering gravel bed river (facies association 3) is dominated by crudely stratified and well imbricated coarse gravel of facies Gm. Church
(1983) and Desloges and Church (1 987) have defined a wandering gravel bed river as a river intermediate between a braided river system and a meandering river system. It is characterized by an irregularly sinuous channel, sometimes divided around channel islands, and in some reaches braided (Church, 1983; Desloges and Church, 1987). Gravel tiom facies association 3 have been documented above medial to distal braided stream sediments (facies association 2), as well as in contact with bedrock. Wandering gravel bed river sediments are distinguished from braided stream sediments by their lateral continuity. Facies association 3 has been traced laterally for distances greater than 100 metres and has been correlated with a similar succession at an equivalent stratigraphic position in another part of the drainage basin. 5.3.4 Facies Association 4: Gulch deposits (Facies Gm, Gh)
The association of horizontally stratified, graded gravel (facies Gh) with lesser
amounts of massive to crudely stratified gravel (facies Grn) characterizes gulch deposits
(facies association 3). Gulch streams occur in narrow, deeply incised valleys, with
weathered and colluviated slopes. Discharge is typically seasonal, such as during
episodic flood events from spring snow melt. The gradient within gulch streams is
moderate to high, resulting in high stream discharge and velocity (Levson and Morison,
1995). High stream capacity and competence results in the deposition of poorly-sorted,
coarse gravel deposits of facies Gh and Gm, with highly angular to subangular clasts of
locally derived lithologies.
5.3.5 Facies Association 5: Aeolian-colluvial (Facies FI, Fm, Fo, and Dms)
Aeolian-colluvial deposits of facies association 4 are characterized by finely
laminated sand, silt and mud (facies FI), massive silt (Fm), organics and organic-rich silt
(Fo) and massive to weakly stratified diarnict (Dms). Increased slope in high relief areas,
lack of vegetation during cooler climates, or following periods of glaciation, and the
presence of permafrost, all enhance slope instability and solifluction, thus contributing to
the abundance of colluvial deposits within the study area. Facies Dms is the most
common colluvial deposit and blankets almost all exposed sections in the study area;
secondary facies ate reworked organics (Fo) and colluviated laminated silt and sand (Fl).
Facies Fm is the only true aeolian deposit, representing windblown loess,
53.6 Facies Association 6: Glacial deposits (Facies Dmm, Sh and Gm)
Glacial deposits are rare in the study area and are characterized by the association of diamict facies Dmm and stratified sand and pebbles of facies Sh. Facies Dmrn is interpreted as a basal till and can be distinguished from resedimented till (colluvium) by a strong a-axis (long) imbrication parallel to paleoflow. An isolated exposure of facies Sh occurs near the basal till and occurs as alternating beds (5-20 cm thick) of well-sorted sand and pebbles and has been interpreted as glaciofluvial outwash deposited from meltwater during the retreat of glacier ice. Table 5.1 Summary of facies and facies associations. I Facies I Description I Interpretation I Facies Association 1 I I I proximal and mediaq I massive to crudely bedded longitudinal bars; to distal braided prograding gravel diffise gravel sheets under stream; wandering high sediment discharge gravel bed river; gulch deposit massive to weakly graded, hyperconcentrated flood gulch deposit; horizontally stratitied 1 flows I proximal braided ( gravel stream stratified gravel with planar progradation of high-relief medial to distal crossbeds barforms; active foresets braided stream stratified gravel with trough secondary infilling of chan- medial to distal Gt cross beds nel scours by traction cur- braided stream rent bedIoad horizontally laminated planar bedflow in an upper proximal and medial Sh sand and pebbly sand flow regime to distal braided stream; glacial planar tabular crossbedded active foreset migration of medial to distal sand and pebbly sand bar kont braided stream trough crossbedded shallow infillings of gravel medial to distal sand and pebbly sand bed forms braided stream , sand, very fme to very bar top sand deposited du- medial to distal I Sr 1 coarse with ripple marks (ring low water stages or 1 braided stream I waning stages of flood sand, silt and mud with overbank. or waning flood medial to distal I fine laminations deposit, or fine-grained braided stream aIluviaVcolluvial fans aeolian/colluvial derived tiom seasonal run-off massive silt windblown loess aeolian/colIuvial organics and organic-rich buried soil (paleosol) or aeolian/colluvial silt transported, reworked soil I I massive to weakly strati- debris flow/mass wasting or Dms fied, matrix-supported colluvial deposit aeolian/coiluviaI (gelifluction/ gravel diamict soiifluction) Dmm massive, matrix-supported till or resedimented till glacial deposit gravel diamict CHAPTER 6 - DEPOSITIONAL PROCESSES
6.1 Grain-Size Characteristics
6.1 .I introduction
Grain-size represents one of several textural features of clastic sedimentary rocks.
Texture of sedimentary rocks is believed to reflect the nature of transport and depositional processes, and characterization of texture can aid in interpreting ancient environmental settings. The size distribution of grains in a sedimentary rock is a hction of: (1) availability of grains of different sizes at the source, (2) transport and depositional processes, and (3) postdepositional diagenetic changes (Boggs, 1987). The reliability of using grain-size as a tool for identifying ancient sedimentary environments is questionable however, because of variability in depositional conditions within major environmental settings. For example, in river systems, the energy conditions and sediment supply may vary considerably horn one river to another, or even within the same river system. As a result, the grain-size characteristics of sediments may show as much variability within different parts of the same environmental setting as between different environments (Boggs, 1987). It is for this reason that grain-size should never be used alone as a tool for environmental interpretation.
A rigorous grain-size analysis was not performed for this study, mainly due to the questionable reliability of grain-size results. Grain-size analysis was conducted primarily to obtain size fractions for heavy-mineral analysis. A total of nineteen bulk gravel samples were collected fiom pay units (those units which contain placer gold and/or heavy minerals) during the 1997 field season. In the lab, samples were split into 1 to 1.5 kg samples. One split was sieved for grain-size analysis, while the other split was panned in order to extract any gold grains, which were fiirther analyzed for gold grain
morphology (see Chapter 7, section 7.1). Samples processed for grain-size analysis were
sieved through #4, # 10, # 18, #35, #60, # 120 and #230 Tyler mesh screens. AAer
weighing, the #18 to XI20 size fractions were sent for heavy-mineral analysis. Results
for grain-size analyses are shown in Appendix A. Results were Wersummarized and
plotted as bar graphs displaying weight percent of gravel, sand and mud for each sample
(see figures 6. la through 6. Ic). A brief discussion of the results is included in section
6.1.2.
6.1.2 Discussion
As mentioned in section 6.1.1, grain-size analysis was completed primarily to
obtain the proper size fractions for heavy-mineral analysis; therefore most of the samples
collected were of alluvial gravel, where heavy minerals and gold would most likely be
present. Some very generalized observations can be made from the results and are discussed as follows.
Most of the alluvial gravel within the study area yield on average 60%-70% gravel, 20%-30% sand and less than 10% mud; all of these gravel samples came from clast-supported gravel units (see figures 6. la - 6. lc). For all creeks, there is a general decrease in grain-size downstream. Moving downstream on an alluvial terrace at Gill
Gulch (from LW-97-09-U I to GILLCUI , see figure 4. I), there is an increase in sand from approximately 15% to 28% and an increase in mud from approximately 0.5%to approximately 2.04%. Moving downstream on Fisher Gulch (fiorn LW-97-17-U1 to
LW-97- 16-U2, see figure 4.1 ), there is an increase in sand fiom 24.72% to 30.56% and an increase in mud fiom 7.66% to 10.1 1%. Similar results are also shown for both Haggart Haggart Ck., alluvial gravel Haggart Ck., alluvial gravel
Haggart Ck., alluvial gravel Haggart Ck.,alluvial gravel
Gill Gulch, alluvial gravel Gill Gulch, alluvial gravel
Figure 6.1 a: Summary of grain size results of alluvial gravel samples from Haggut Creek and Gill Gulch. Gill Gulch, alluvial gravel Gill Gulch, alluvial gravel
Gill Gulch, alluvial gravel Fisher Gulch, alluvial gravel
Fisher Gulch, alluvial gravel Fisher Gulch, alluvial gravel
Figure 6.1b: Summary of grain size results of alluvial gravel samples fiom Gill Grtlch and Fisher Gulch. Dublin Gulch, alluvial gravel Dublin Gulch, alluviai gravel
Dublin Gulch, Reid till Haggart Ck.,resedimented till
Dubiin Gulch, debris flow Haggart Ck.,debris flow
Figure 6.l c: Summary of grain size results for: alluvial gravel (Dublin Gulch); till (hblin Gulch) and resedimented till (Haggart Ck.); and debris flows (Dublin Gulch and Haggat Ck.). Creek (downstream from LW-97-01-U2 to LW-97-04-U 1, see figure 4.1) and Dublin
Gulch (LW-97-204 1 to L W-97-2 1-U 1, see figure 4.1 ) (see figures 6.1 a to 6.1 c).
Not surprisingly, debris flows show a great deal of variability. In this case, grain-
size ieflects primarily the source material; whereby little reworking has occurred. since
material moves downslope at a very rapid rate. Sample LW-97-274 I (see figure 4. l),
collected from an east-facing slope on the right-limit of Haggart Creek, has a high content
of fines (23% sand and 33% mud) compved to debris flow LW-97-22-U 1 (see figure 4.1)
found at Dublin Gulch on a northwest-facing slope. Presently, as likely in the past, these
two areas differ greatly in their source material. Slopes on the right-limit of Haggart
Creek are rich in permafrost and black "mucks" (organic-rich silt), while the northwest-
facing slopes on the left-limit of Dublin Gulch tend to be slightly better drained with less
fines and less permafrost.
A sample of resedimented (Reid) till and Reid till were also collected from
Haggart Creek and Dublin Gulch respectively. Grain-size results were compared for
these samples and are shown in Figure 6.1~.Unexpected results showed significantly
more fines (40.45 % mud) in the sample of resedimented till compared to the till (29.65%
mud). One would expect to find more silt and clay in a till due to glacial abrasion,
likewise one would expect to fmd more coarser material in a resedimented till as it moves
downslope and picks up weathered bedrock. At the site where the resedimented till was
collected, a very poorly exposed unit of massive silt exists, which may represent proglacial lake sediments; this unit lies stratigraphically below the resedimented till. If lake sediments are present, then this might explain the high abundance of silt and clay in the resedimented till, since the colluviurn (resedimented till) would rework the underlying
lake sediments as it moved downslope.
The above observations are very general. It is clear however from the results, that grain-size data is highly variable, even within the same facies and can not be relied upon as a sole tool for interpretation of sedimentary environments.
6.2 Clast Lithology and Provenance
6.2.1 Introduction
Clast lithology data were gathered simultaneously while measuring fabric of various alluvial gravel and diamicton units within the study area. Clast lithologies are included with fabric data in Appendix B. By examining the local bedrock type within the area, clast lithologies could be grouped as proximal, medial, or distal in origin. Proximal lithologies are locally derived, medial lithologies are derived from within the basin and distal lithologies originate outside the basin. Proximal lithologies include various schists and quartzites. Medial lithologies include granodiorite, diorite and vein quartz. Distal lithologies are minor and include Keno Hill quartzite (grey quartzite with abundant quartz veins), gabbro and rare sedimentary clasts. The total percent of proximal, medial and distal clasts are summarized for each creek and are shown in Table 6.1. Haggart Creek includes units LW-97-02-U3, -02B-U3, -04-Ul,-05-U3, -05-U6, -08-U6, -15-U4, -25-
U2, -27-U I and -27-U3. Dublin Gulch includes units LW-97-20-U 1, -2 1-U 1, -2 142, -
22-U 1, -22-U2 and -23-U I. Units L W-97-09-U I, - 10-U 1, - 12-U 1, GILL4-U 1, GILL3-
U 1 and LW-97- 14-U 1 are found at Gill Gulch, while units L W-97- 16-U 1 and - 1742are found at Fisher Gulch. Table 6.1
Summary of clast provenance. Drainage % Proximal % medial %Distal Haggart Creek 86 11 3 Dublin Gulch 83 14 3 Gill Gulch 92 6 2 Fisher Gulch 98 -3 0
6.2.2 Discussion
As shown in Table 6.1, creeks within the study area are dominated by proximal
clast lithologies, with lesser amounts of medial clast lithologies and rare distal clast
lithologies. Fisher Gulch shows the highest percentage of proximal clasts at 98% due to
the presence of gulch deposits, which are comprised almost entirely of local weathered
bedrock. Gill Gulch contains a slightly higher number of medial clasts compared with
Fisher Gulch due to the presence ofa buried Haggart Creek alluvial terrace underneath
the Gill Gulch fan. Haggart Creek, being the main drainage within the study area, would
carry with it medial clast lithologies introduced by tributary streams. Dublin Gulch has the highest percentage of medial clast lithologies. The abundance of medial clast
lithologies is due to the presence of a local intrusive body of granodiorite which is located at the headwaters of Dublin Gulch. Both Dublin Gulch and Haggart Creek contain the highest percentage of distal clast lithologies. It is presumed that distal lithologies were brought into the study area via regional ice sheets. Reid ice was the last ice sheet to advance into the study area, leaving behind till deposits within Dublin Gulch, including a well preserved terrace along the left-limit of Haggart Creek. CHAPTER 7 - PLACER GOLD MINERALIZATION
7.1 SEM Analysis and Gold Morphology
7.1.1 Introduction
A total of sixteen heavy-mineral concentrate samples were collected from various
sites within the study area. Concentrates were panned in the lab and gold grains were
hand-picked for hrther examination. Gold grains were initially examined using a binocular microscope and features of grains such as roundness (after Powers, 1953), sphericity and habit (crystalline, sub-crystalline, dendritic and wire-gold) were noted. A summary of gold grain roundness is shown in Table 7.1, while a summary of gold morphology from SEM analysis is shown in Table 7.2.
Table 7.1
Summary of gold grain roundness; V.A.= very angular; A.= angular; S.A.= sub- angular; S.R.= sub-rounded; R.= rounded; W.Rr well rounded.
V.A. A. S.A. S.R R W.R Creek (%) (%) (%) (%) (%) Dublin Gulch 1 11 22 34 32 0 Haggart Creek 0 6 33 44 I5 2 Gill Gulch 0 2 1 27 34 18 0 Fisher Gulch 6 8 36 30 20 0 i Table 7.2
Summary of gold morphology from SEM analysis.
Diagnostic Features and Creek Folded Pitted Striated Sheared Accessory Minerals Dublin Yes Yes Yes yes crystalline to sub-crystalline grains; some wire gold em bedded quartz Haggart Yes Yes no yes sub-crystalline to highly hammered and flattened grains em bedded feldspar Gill Yes Yes no yes sub-crystalline to highly hammered and flattened grains embedded titanium oxide crystal Fisher Yes Yes no yes crystalline to sub-crystalline gold, some wiry to weakly den- dri t ic em bedded feldspar
7.1.2 Discussion
Shape characteristics of gold particles falling in the 0.2 to 1.5 mm range can be used to estimate the distance of transport of placer gold from its lode source (Knight et al., 1994). Gold grain morphology varied widely within the study area (see figures 7.1 through 7.8); however, most gold grains were found to fall in the sub-angular to rounded range (see Table 7.1). Most rounding of gold particles is though to take place in the fmt
5 km from the lode source (Boyle, 1979; McTaggart and Knight, 1993; Knight et al.,
1994). The known lode source for the study area occurs at Potato Hills at the headwaters Figure 7.1 : Scanning electron photomicrograph of gold grain from an alluvial gravel on the right limit of Haggart Creek (LW-97-26- U 1). Note composite nature of the grain, folding and rounding.
Figure 7.2: Scanning electron photomicrograph of gold grain from alluvial gravel on left limit ofHaggart Creek (LW-97-01-U 1). Gritin is sub-crystallinewith folded extensions and pitted surface texture. Figure 7.3: Scanning electron photomicrograph of gold grain from an alluvial gravel at Fisher Gulch. Grain is composite and sub- crystalline.
Figure 7.4: Scanning electron photomicrograph of gold grain from alluvial gravel at Dublin Gulch. Grain represents slightly rounded wire gold. Figure 7.5: Scanning electron photomicrograph of gold grain from an alluvial gravel on the right limit of Haggart Creek (LW-97-26-Ui). Grain is rounded; note shearing and striations.
Figure 7.6: Scanning electron photomicrograph of gold gain From an alluvial gravel at Gill Gulch (Gill 4). Grain is sub-crystalline with highly pitted surface texture. Figure 7.7: Scanning electron photomicrograph of gold grain from an alluvial gravel at Gill Gulch (pay). Gold gmnis sheard, exposing crystal faces.
Figure 7.8: Scanning electron photomicrograph of gold grain from an alluvial gravel on the right-limit ofXaggart Creek. S pecirnen is a sub-rounded gold grain with an embedded feldspar grain. of Dublin Gulch, therefore it is not surprising that most grains display some degree of
rounding.
Angular and sub-angular grains are also common within the study area. Dublin
Gulch contains a percentage of very angular to angular gold grains ( 1% and 1 1%
respectively) and this is explained by its proximity to the known lode source. Gill Gulch,
which is located approximately 7 km (via Dublin Gulch and Haggart Creek) from Potato
Hills, has an unusually high percentage of angular grains (2 1%), of which a number are
sub-crystalline. The presence of sub-crystalline (angular) grains suggests a nearby
secondary lode source for Gill Gulch. Likewise, Fisher Gulch contains a relatively high
percentage of very angular and angular grains (6% and 8% respectively). Fisher Gulch is
a right-limit tributary to Haggart Creek and lies north (upstream) of Dublin Gulch. As
mentioned above, it is believed that most of the placer gold originated from Potato Hills
at the headwaters of Dublin Gulch and was carried downstream as alluvial placers.
Therefore, it would be impossible for gold from Potato Hills to have reached Fisher
Gulch, unless it was brought over by the last glacial ice sheet (Reid ice overtopped Potato
Hills). If transported by ice, it is highly unlikely that crystalline gold would be preserved.
Therefore, based on the presence of crystalline gold and the geographic location of Fisher
Gulch with respect to Potato Hills and Dublin Gulch, it is believed that Fisher Gulch contains its own local source of gold.
Scanning Electron Microscope analysis was most useful in examining surface texture features of the gold grains. The surface texture is a record of both hammering and abrasion (Knight et al., 1994). Hammering will deform the whole particle, while abrasion affects only the outermost surface of the particle. Two common surface textures are pits and scratches (see figures 7.5 and 7.6). Pits were found in grains of all samples. Pits may
form by casts of smaller sedimentary particles, by folding or smearing, or by abrasion and
etching (Knight et al., 1994). Surface scratches, in the form of striations, were found on
grains in Haggart Creek and Dublin Gulch; these areas also included gold particles with
embedded grains of quartz and feldspar. Striations and embedded grains may indicate
some degree of ice transport (LeBarge, 1993). Folded grains were found in all samples and reflect fluvial reworking of the particles as they roll and collide with other particles
(see figures 7.1 and 7.2). Shearing is also found on gold grains within all samples.
Shearing is caused by persistent hammering, that is, if the gold grain is hammered hard enough and long enough, it is likely to break by shearing before it is extremely flattened
(Knight et al., 1994).
7.2 Heavy-Mineral Analysis
7.2.1 Introduction
A total of 19 samples were processed for heavy-mineral analysis. Analysis began with panning the -1 8 to -35 sieved size fraction into a 3 to 20 gram heavy mineral concentrate. Each pan was checked for gold content and the percentages of the magnetic and nonmagnetic fractions were noted. The heavy mineral concentrate was then placed into a separating he1containing methylene iodide; the separating he1would allow rock fragments and minerals with a specific gravity of greater than 3.32 to sink to the bottom. After drying, the heavy mineral concentrate was examined using a binocular microscope. Basic mineral identification equipment was used, including longwave and shortwave ultraviolet light, magnet and dilute hydrochloric acid. Results for the heavy-
mineral analysis are shown in Table 7.3a and 7.3 b.
7.2.2 Discussion
The most common heavy mineral found within the study area is sheelite, which occurs in 12 out of the 19 samples and is found on all creeks except for Fisher Gulch.
Scheelite is known to originate from several different sources in the area including quartz veins, pegmatite bodies and skam bodies (figure 2.4). These deposits occur in the granitic rocks, quartzites, phyllites and schists, however most occur within or adjacent to the granodiorite pluton on Potato Hills.
The second most abundant heavy minerals are pyrite and arsenopyrite, which both occur in 6 out of the 19 samples; pyrite and arsenopyrite can be found in samples on all creeks in the study area. A number of quartz-menopyrite-scorodite-gold veins have been noted in the granodiorite, homfels and phyllite-quartzite sequences within the study area
(Boyle 1965, 1979; Hitchins and Orssich, 1995). These are within fissure veins that occur at the headwaters of Eagle, Stewart and Olive Gulches, as well as on Haggart Creek at the mouth of Gill Gulch (see figure 2.4). The veins are locally of high grade (up to 14 g/t are common), but are of limited strike length (Hitchins and Onsich, 1995).
Heavily weathered graphitic schist was sampled from a vein at the mouth of Gill
Gulch and was panned. The resultant heavy mineral concentrate was rich in pyrite, with a
few grains of crystalline to subrounded gold. Although these veins do not produce
economic reserves, they remain important sources of gold for placers within the study
area. It is likely that the sub-crystalline gold found in sample LW-97-12 on Gill Gulch
originated fiom one of these nearby veins. It is also possible that these veins may be a Table 7.3a
Summary of results for heavy-mineral analysis for Haggart Creek and Dublin Gulch. I I I I Number of Gold 1 Associated I Section Creek Sediment Grains Heavy lMinerals LW-97-01 Haggart alluvial > 10 pyrite (up to 50%) (Unit 1) gravel irregular to flattened arsenopyrite (50%) su brounded LW-97-0 1 Haggart alluvial 0 pyrite (up to 50%) (Unit 2) gravel malachite (coated on 1% of pyrite grains) arsenopyrite (trace) LW-97-04 Haggart alluvial 0 pyrite (70-90%) (Unit 1) gravel arsenopyrite (< 1%) I I I I Iboulangerite (trace) I malachite (trace) scheelite (trace) LW-97-05 Haggart alluvial 0 rock fragments (40-60%) (Unit I) gravel scheelite (trace) LW-97-15 Haggart resedimen- 0 ilmenite (40-60%) (Unit I) ted till pyrite (2-3%) scheelite (2-3%) LW-97-26 Haggart alluvial 0 rock fragments (90-95%) (Unit I) gravel scheelite (1%) LW-97-27 I Haggart 1 alluvial I 0 1 pyrite (3040%) 1 (Unit I) gravel arsenopyrite (3040%) scheelite ( I-2%) cassiterite (1%) scheelite (5565%) (Unit I) zircon (2-3%) 6 (crystalline in quartz) scheelite (55-60%) (Unit 1) gavel I (subrounded in rutile (7- 15%) quartz) arsenopyrite (trace) LW-97-22 Dublin debris 0 rock fragments (75-90%) (Unit 1) flow scheelite (trace) LW-97-22 Dublin Reid till 0 pyrite (25-30%) (Unit 2) arsenopyrite (5- 15 %) siderite (24%) boulangerite ( 1%) Table 7.3b
Summary of results for heavy-mineral analysis for Gill Gulch and Fisher Gulch. I 1 Number of Gold I Associated 1 Sediment Grains Heavy Minerals LW-97-09 Gill alluvial 0 rock Fragments (60-90%) (Unit 1) gravel scheelite (5-15%) manganese gamets (trace) LW-97- 10 Gill alluvial 0 rock hgments (80-90%) (Unit I) gravel scheelite (5- 10%) LW-97- 12 Gill alluvial 0 rock tiagments (60-90%) (Unit 1) gravel rutile (24%) anatase (1%) corundum (I grain) cassiterite (trace) periglaciai 0 rock fragments (6040%) fan ilrnenite (5- 15%) scheelite (5-10%) I massive limonitic hg- t ments ( l-2%) GILL4 Gill ' alluvial I goethi te pseudomorphs (Unit 1) gravel after pyrite (50-60%) scheelite (5- 15%) LW-97- 16 Fisher alluvial 0 schistose rock hgments (Unit I) gravel (50-80%) r cassiterite (24%) alluvial 0 limonite coated rock gravel fragments (80-90%) alluvial 0 schistose rock fragments (80-90%) cassiterite (3-5%) 1 ( massive goethite (34%) 1 source of gold for Fisher Gulch placer deposits, however, no veins of this type have been
mapped in that area as of yet. Mapping by Boyle (1 965) shows a granodiorite exposure
at the headwaters of Fisher Gulch (see figure 2.4) and this may also be a potential source
of gold for the Fisher Gulch placers.
Cassiterite is another relatively common heavy mineral associated with the placer
deposits in the study area and is found in 4 out of the 19 samples. Cassiterite occurs in
samples from Haggart Creek, Fisher Gulch and Gill Gulch. Cassiterite was discovered in
placer deposits on Dublin Gulch in 1943 and was soon traced to a source above Ann
Gulch on Tin Dome (see figure 2.4) (Boyle, 1965). Cassiterite occurs as small showings
in tourmalinized breccia zones in quartzite and phyllite (Boyle 1965, 1979; Hitchins and
Orssich, 1995).
Heavy minerals that occur in minor or trace amounts within the study area include
rutile, anatase, zircon, corundum, manganese garnet, boulangerite, siderite and malachite.
Malachite is likely related to the oxidation of chalcopyrite, which is found as an
accessory mineral to the sheeted quartz veins within the Dublin Gulch granodiorite stock
on Potato Hills.
7.3 Controlling Mechanisms for Placer Gold Mineralization
73.1 Bedrock sources
A prerequisite to the formation of placer gold deposits is a local bedrock source.
In the Haggart Creek area, the most widely known source for gold is sheeted quartz veins within the Dublin Gulch granodiorite stock. This resource has been estimated at approximately 64.5 x 1o6 tomes at a grade of 1.03 g/t Au (Hitchins and Orssich, 1995). In addition to gold in sheeted quartz veins, gold also occurs within quartz-arsenopyrite-
pyrite-scorodite-gold veins (Boyle, 1965, 1979; Hitchins and Orssich, 1995; Smit et ai.,
1995). These veins occur as fissure veins within the granodiorite as well as within the
phyllite-quartzite sequence. When found within the phyllite, or schist, the bedrock is
brecciated and highly tiactwed; as a result the schist is disintegrated to a clay-rich deposit
(figure 7.9). The importance of these veins to local placer deposits is twofold: fnstly, the
weathered and disintegrated nature of these veins allows for gold to be released into the
system as alluvial placers; secondly, the high clay-rich content of the weathered veins
acts as a potential trap and may concentrate alluvial placer gold as it moves downstream.
It is believed that these veins are source to the crystalline and sub-crystalline gold found
on Gill Gulch and Haggart Creek and they are believed to be a potential source for the
Fisher Gulch placers.
7.3.2 Paleoenvironmental controls
The formation of placer gold deposits relies on the weathering and subsequent release of gold fiom lode sources. Tertiary time was marked be extensive tectonic uplift and a hot, humid climate (Boyle, 1979). The subtropical climate resuited in prolonged and extensive weathering of bedrock to depths of several tens of metres, while continual uplift resulted in extensive downcutting by stream and river systems. In the Haggart
Creek area, gold fiom local lode sources would have been released to form abundant, rich alluvial placers. During Quaternary time, the Haggart Creek area was subjected to several glaciaVinterglacial periods. It is has been generally accepted that glaciation dilutes placer deposits due to the erosive and scouring action of glacial ice. Upper
Haggart Creek, however, is transverse to paleo ice-flow transport directions; therefore Figure 7.9: Weathered out quartz-arsenopyrite-pyrite-scorodite-goldvein within schist bedrock on Haggart Creek, near Gill Gulch. Note high clay content. Hammer measures 30 cm. there was limited glacial scour within Upper Haggart Creek valley since ice moved up-
valley, or up-gradient. As a result, during glacial periods, glacial sediments were
deposited as blankets preserving underlying placer deposits. In contrast, interglacial
times represented warmer periods, which resulted in extensive weathering, thus releasing
more gold into the system. Subsequent downcutting during interglacial times would have
reworked and reconcentrated pre-existing placer deposits.
7.3.3 Sedimentological and hydrological controls
The majority of the gold recovered in the study area is derived fiom massive to crudely stratified (commonly imbricated) gravel. The gold is found in the lower layers of the alluvium either on bedrock, in a zone a few feet above the bedrock, or in crevices and fractures within bedrock. Bedrock in the study area is particularly favourable for the concentration of gold as it consists of alternating thin beds of soft schist and hard quartzite; this assemblage forms natural rimes when perpendicular to the stream or river course and essentially acts as a natural sluice system. There are many possibilities as to why gold is found on or near bedrock. Cheney and Patton (1967) view the concentration of gold on bedrock as the result of extensive scouring and sluicing of the whole sediment column in stream and river channels during unusually large flooding events. Tuck (1968) attributes the concentration to long periods of erosion during which time the stream is mainly downcutting. Weathering and erosion are separating gold fiom the country rock and subsequently concentrating gold in the bottom of the valley. During this time of extensive vertical erosion, gold as it is liberated occurs on or near bedrock since the stream is essentially flowing on bedrock (Tuck, 1968). Other areas in which gold may be concentrated include obstructions in stream beds (e.g. bars), on the inside curves of fast-flowing meanders and in main streams at the mouths of tributaries. The latter two sources of concentration are due to an abrupt change in stream bed geometry, which causes a slackening of the water flow. As a result, flow separation occurs whereby gold and other heavy minerals are segregated and deposited
(Boyle, 1979). CHAPTER 8 - STRATIGRAPHY AND PALEOGEOGRAPHIC
RECONSTRUCTION
8.1 Introduction
A total of 28 vertical sections were logged in the field. Twenty representative
sections have been selected and are included as figures in this chapter; the remaining
logged sections are shown in Appendix C. Facies associations will be discussed in
section 8.2. Section 8.3 examines the lateral relationships within each drainage.
Stratigraphic correlation was based on field relationships and facies trends and sections
were plotted using elevation above sea level as a datum. A discussion of paleogeographic
history is included in section 8.4.
8.2 Schematic Profiles and Facies Associations
8.2.1 Fisher Gulch
Fisher Gulch is a right-limit tributary to Haggart Creek and enters Haggart Creek
approximately 750 metres upstream from the confluence with Dublin Gulch (see figure
4.1). Fisher Gulch displays the typical morphology of a gulch stream with steep slopes in
a narrow, confined valley (figure 8.1). Two vertical sections were logged on Fisher
Gulch (LW-97- 16 and LW-97- 17) and are shown in figures 8.2 and 8.3 respectively.
Section LW-97-17 is located upstream of section LW-97-16 (see section location map,
figure 4.1) and both sections are characterized by facies Grn and Gh (massive to crudely stratified gravel and massive to crudely graded gravel respectively). Together these facies correspond to facies association 4 of gulch deposits. Clasts within these deposits are typically highly angular and range from boulder size to as small as pebble size. Figure 8. 1: Photo of Fisher Guich on the right-limit of Haggart Creek, upstream of Dublin Gulch. Note the steep slopes in a narrow, confined valley. Thickness Facies Association 4 (m) Gulch Deposit
G SM
Figure 8.2: Vertical logged section of LW-97- 16 on Fisher Gulch. Covered Gm
~h Facies Association 4 Thickness Gulch Deposit (m)
Covered
G SM
Figure 8.3: Ver(:ical logged section of LW-97-17 on Fisher Gulch. Clast lithologies are locally derived. Placer gold in Fisher Gulch is mostly concentrated
in the lowermost, coarse boulder units, immediately above bedrock
8.2.2 Dublin Gulch
Dublin Gulch is a left-limit tributary to Haggart Creek and enters Haggart Creek
approximately 800 metres upstream from the confluence with Gill Gulch (see figure 4.1).
A total of six vertical sections were logged in Dublin Gulch and three sections were
chosen to be included in this discussion. Section LW-97-21 represents the fbrthest
upstream exposure on the left-limit of Dublin Gulch (see figure 4.1). A photo of section
LW-97-21 is shown in figure 8.1. This section consists almost entirely of facies Gm and
Gh (figure 8.5). Units I through 3 all have gradational contacts. Clast shape ranges from angular to rounded. Clast lithologies consist of approximately 80% granodiorite and 20% combined quartzite and schist. Fabric from unit I shows a strong a-axis (long) imbrication perpendicular to paleoflow. Direction of paleoflow was measured to be due north, that is, coming out of the side valley (see figure 4.1). Units 1 through 3 are interpreted as being deposited in a proximal alluvial fan environment (facies association
1). The source for the alluvial fan sediments is Stuttle Gulch, a left-limit tributary to
Dublin Gulch. Facies Dms (massive to weakly stratified diarnict) caps the alluvial fan package and is interpreted as recent co lluvium of facies association 4 (aeo lian-colluvial). Figure 8.4: Photo of section LW-97-2 1 on the left-limit of Dublin Gulch showing relatively thick package of proximal alluvial fan gravel (facies association 1). Measured section is approximately 13.7 m thick. Dms
Thickne (m)
Facies Association 5 Aeolian-Colluvial Unit 4
Facies Association 1 Proximal Alluvial Fan Units L-3
G SM Figure 8.5:Vertical logged section of LW-97-2 1 on the left-limit of Dublin Gulch. Section LW-97-22 is located approximately 400 metres downstream of LW-97-2 1
and is shown in figure 8.6. The logged section is shown in figure 8.7 and includes two
units of facies Dms and Dmm (massive, matrix-supported, gravel diamict). The
lowermost unit 1 (facies Dms) is very poorly-sorted with highly angular clasts, as well as
rip-up clasts of organic-rich silts. Clast lithologies are predominantly quartzite with
minor granodiorite. Wood sampled from this unit was radiocarbon dated at >37,740 B.P.
(Beta- 1 1 1603). Unit 1 is interpreted as a debris flow.
Unit 2 is composed of a highly competent, matrix-supported gravel diamict.
Clasts are subangular to well-rounded and range from pebble to boulder size; striated boulders are common. Matrix is fine sand to clay. Unit 2 forms an erosional contact with underlying unit I (figure 8.8). Unit 2 displays a strong fabric with a-axis (long) parallel to paleoflow. Paleoflow direction was measured at approximately 15 degrees east of north, that is, coming out of the side valley (see figure 4.1). Unit 2 is interpreted as a
Reid basal till.
Section LW-97-23 is located on the left-limit of Dublin Gulch approximately 200 metres downstream of section LW-97-22. The logged section is shown in figure 8.9.
Unit 1 is composed of alternating beds of well-sorted, horizontally stratified, sand and pebbly sand (facies Sh) with well-sorted, imbricated beds of pebble gravel (facies Gm)
(see figure 8.10). Paleoflow direction was measured at approximately 68 degrees east of north, that is, coming out of the side valley (see figure 4.1). Based on fabric data, the fme nature of the sediments and facies associations, this unit was interpreted as a glaciofluvid outwash (facies association 6). Unit 2 is in sharp contact with Unit I, however the Figure 8.6: Photo of section LW-97-22 on the left-limit of Dublin Gulch showing pre-Reid debris flow underlying Reid till. Measured section is 13.7 m thick. Facies Association 6 Glacial Unit 2
Facies Association 5 Aeolian-Colluvial Unit I
G SM Figure 8.7: Vertical logged section of LW-97-22 on left-limit of Dublin Gulch. Figure 8.8: Photo of erosional contact between pre-Reid debris flow and overlying Reid till of section LW-97-22 on the left-limit of Dublin Gulch. Pen measures 15 crn. Facies Association 5 Aeolian-CoIluvial
Thickness (m) Facies Association 6 Glacial
Figure 8.9:Vertical logged section of LW-97-23on the left-limit of Dublin Gulch. Figure 8. LO: Photo of alternating beds of horizontally stratified sand and pebbly sand (facies Sh) with beds of well-sorted, imbricated pebble gravel (facies Gm) of section LW-97-23 on the left-limit of Dublin Gulch. Shovel measures approximately 1.2 m. contact does not appear to be erosive. Unit 2 consists of a poorly-sorted, matrix-
supported, pebble diamict (facies Dms). Clasts are predominantly angular to subangular
and matrix is mainly silt and clay with lesser amounts of fine sand. Coarse sand to grit
lenses approximately 2-10 cm thick are scattered throughout the unit. The entire unit is moderately to heavily cryoturbated. This unit is interpreted as colluviurn of facies association 5 (aeolian-colluviai).
8.2.3 Haggart Creek (right-limit near Gill Gulch)
Gill Gulch is a right-limit tributary to Haggart Creek and enters Haggart Creek approximately 800 m downstream of the confluence with Dublin Gulch (figure 4.1). A total of eight sections were logged in this area, of which five will be discussed in this section.
Section LW-97- 10 is located Mestupstream at an elevation of approximately
77 1 rn a.s.1.. A photo of this section is shown in figure 8.1 1. In areas adjacent to section
LW-97- 10, the lowermost alluvial gravel unit was found to be in contact with bedrock.
This lowermost alluvial gravel unit (unit 1 of section LW-97- 10) is therefore interpreted to represent an abandoned alluvial terrace. Unit 1 is comprised of a clast-supported, poorly- to moderately-sorted, pebble-cobble gravel with isolated boulders (figure 8.12).
Clasts are subangular to rounded and weakly to moderately imbricated. Fabric measured on this unit was relatively scattered, however a fabric measured in the same gravel of section LW-97-09 showed a strong a-axis (long) imbrication perpendicular to paleoflow.
Pateoflow direction was measured to be to the southeast. This gravel unit (facies Gm) represents a channel gravel and can be traced a lateral distance downstream of greater
Facies Association 5
Facies Association 5 Thickness Aeolian-Colluvial Im)
Facies Association 3 Gm 1(2 1 8' Wandering Gravel Bed River
Figure 8.12: Vertical logged section of LW-97- 10 on the right-limit of Haggart Creek near Gill Gulch. than 20 m and has also been documented upstream a lateral distance of greater than 50 m
(pers. comm., Tackis, 1997). This alluvial gravel has been interpreted as part of a
wandering gravel bed river sequence (facies association 3).
Units 2 through 8 are composed of organics (facies Fo), organic-rich, laminated
fine sand to clay (F1) and massive to weakly stratitied pebble-cobble diamict (facies
Dms). Facies F1 may contain lenses 2 to 5 cm thick of coarse sand and grit. All units
contain organics in the form of laminae (0.5-3.0 cm thick) of organic-rich silt, or small
twigs and woody debris (
contact with unit 1) yielded a radiocarbon age of 12 3 10 k 120 BP (Beta-1 09 150). All
units are moderately to heavily cryoturbated. Units 2 through 8 are interpreted as
colluviai deposits of facies association 5 (aeolian-colluvial). Unit 8 forms an erosive
contact with underlying unit 7 and is interpreted as a more recent colluvium.
Section LW-97- 1 1 is exposed approximately 100 m in the downstream direction
from LW-97- I0 and approximately 10- 15 m towards the side-valley fiom LW-97- 10
(figure 8.13). This section is poorly exposed (see figure 8.14), however it can be
correlated with the uppermost units of LW-97- 10. Figure 8.15 shows the vertical logged
section of LW-97-11. The entire section is comprised of facies FI and Dms and is
interpreted as colluvium (facies association 5, aeolian-colluvial). All units are heavily cryoturbated as is shown by extreme sediment mixing (figure 8.14). An ice-wedge was documented at the base of unit 6 and is shown in figure 5.7.
Section LW-97-14 is located approximately 200 m in the downstream direction fiom LW-97- 11 (see figure 8.13). The measured section is approximately 5.2 m thick Figure 8.13: Photo of site locations on the right-limit of Haggart Creek near Gill Gulch (LW-97- ). Flow of Haggart Creek is from right to left in the photo. Figure 8.14: Photo of section LW-97-11on the right-limit oMaggart Creek near Gill Gulch. Pogo measures 1.25 m. Facies Association 5 Thickness Aeolian-Colluvial (m)
Figure 8.15: Vertical logged section of LW-97-11 on the right-limit of Haggart Creek near Gill Gulch. and is shown in figure 8.16. Unit 1 of section LW-97- 14 is composed of a poorly-sorted,
clast-supported, pebble-cobble gave1 with isolated boulders (facies Gm). Clasts are
predominantly angular to subangular with minor subrounded clasts. The whole unit is
moderately imbricated and shows a strong fabric of a-axis imbrication parallel to
paleoflow. The paleoflow direction was found to be almost due south at 178 degrees; this
flow direction is parallel to modern Haggart Creek. The poor sorting, presence of
boulders and angular clasts indicates a proximal source. This unit is believed to represent
a proximal braided stream sequence (facies association 1) of paleo Haggart Creek. Unit 2
is composed of well-sorted, massive silt (facies Fm); this unit is not laterally continuous.
Ventifacts were documented at the contact with unit 1. Unit 2 is believed to represent a
McComelI-age loess. Based on the above evidence, unit I is interpreted as reworked Gill
Gulch periglacial fan (McCo~ell-age)by paleo Haggart Creek. This section is located at what would be the toe of Gill Gulch fan and could have easily been reworked by Haggart
Creek some time during the late McConnell to post-McConnell (see figure 8.13). Unit 3 of section LW-97- 14 consists of poorly-sorted, matrix-supported pebble-cobble diamict
(facies Dms). Unit 3 forms an erosive contact with underlying unit 2. Unit 3 is interpreted as recent colluvium.
Section GILL3 is located approximately LOO rn in the downstream direction from section LW-97-14 and approximately 30-50 m away from the side valley with respect to
LW-97- 14 (see figure 8.13). A photo of GILL3 is shown in figure 5.17 and the vertical logged section is shown in figure 8.18. GILL3 is composed of similar facies to those found in section LW-97-14. The entire section consists of massive to crudely graded cobble gravel with isolated boulders (facies Gm and Gh). The gravel consists of Facies Association 5 Aeolian-Colluvial
Thickness (m) Facies Association I Proximal Braided
Figure 8.16: Vertical logged section of LW-97- 14 on the right-limit of Haggart Creek near Gill Gulch. Figure 8.17: Photo of section GILL3 on the right-limit of Haggart Creek near Gill Gulch. Measured section is approximately 7.3 rn thick. Thickness Facies Association 1 (m) Proximal Braided
Covered
Figure 8.18: Vertical logged section of GILL3 on the right-limit of Haggart Creek near Gill Gulch. predominantly angular to subangular clasts with minor amounts of subrounded to
rounded clasts. The gravel is moderately to weakly imbricated. Fabric measured %om
unit 1 displays an a-axis imbrication perpendicular to paleoflow. Fabric shows paleoflow
to the southeast at approximately 185 degrees (parallel to modem-day Haggart Creek).
GILL3 can be correlated with section LW-97- 14 and is interpreted as reworked toe of
Gill Gulch periglacial fan by paleo Haggart Creek.
Section GILL4 is located approximately 200 m in the downstream direction from
GILL3 and approximately 20-40 m towards the side valley with respect to GILL3 (see
figure 8.13). The vertical logged section is shown in figure 8. i 9. GILL4 is composed of
similar units to L W-97- 10. Unit I consists of a moderately-sorted, clast-supported,
pebble-cobble gravel with a boulder lag at the base (facies Gm); unit 1 is in contact with
bedrock. Fabric was measured on unit I and paleoflow was established to be south at
approximately 185 degrees. Units 2, 3 and 4 are comprised of organic-rich, massive to
laminated, fine sand to clay (facies Fi and Fo). Organics are in the form of organic-rich
silt laminae (0.5 to 4 cm thick) and small pieces of woody debris. Unit 5 consists of a
poorly-sorted, matrix-supported, pebble-cobble diarnict (Dms). GILL4 has been
correlated with LW-97- 10 and represents a wandering gravel bed sequence (facies
association 3) overlain by colluvium (facies association 5, aeolian-colluvial).
8.2.4 Haggart Creek (left-Limit, downstream of Platinum Gulch)
Section LW-97- 15 is located at the upstream end of those sections measured on the left-limit of Haggart Creek. Section LW-97-15 is located approximately 500 m downstream of the confluence of Platinum Gulch with Haggart Creek (see figure 4.1).
The vertical logged section is shown in figure 8.20. Unit 1 consists of very poorly-sorted 4.2 3.8 3.7
Facies Association 5 Aeolian-Colluvial Thickness (m)
1.2
0.6 Facies Association 3 Bed
Figure 8.19: Vertical logged section of GILL4 on the right-limit of Haggart Creek near Gill Guich. Facies Association 5 Aeolian-ColIuvial
Thickness (m)
Figure 8.20: Vertical logged section of LW-97- 15 on the left-limit of Haggart Creek downstream of Platinum Gulch.. pebble-diamict, with minor cobbles (facies Dms). Clasts are subangular to subrounded.
Unit I is heavily cryoturbated. Unit 1 is interpreted as a debris flow unit.
Unit 2 consists of a thin unit of stratified pebble-cobble gravel and planar-tabular
crossbedded pebbly sand (facies Gm and Sp respectively). Unit 3 (facies Dms) is similar
to unit I, however it is less cryoturbated. Units I through 3 are believed to have been
deposited in a proximal braided stream environment as shown by the presence of alluviai
gravel in association with debris flow units (facies association 1). Unit 4 consists of very
pooriy-sorted, matrix-supported, pebble-diamict with minor cobbles; matrix is fine sand
to silt and clay. The entire unit is highly competent and well-cemented. Unit 4 has many
characteristics of a till, however it lacks well-rounded clasts, boulders and a strong fabric
(a-axis parallel to paleoflow). Fabric measured on this unit was highly scattered. Unit 4
is interpreted as resedirnented Reid till.
Section LW-97-08 is located approximately 130 rn downstream of section LW-
97- 15. This section was logged in a gully exposure approximately 70 m upstream of
LW-97-01.Section LW-97-08 was logged in order to obtain a closer examination of the
uppermost units, which may also correspond to the uppermost units of LW-97-01. The
vertical logged section of LW-97-08 is shown in figure 8.2 1. Units 1 through 4 of section
LW-97-08 are composed of cryoturbated, massive to weakly stratified, pebble to pebble- cobble diamicts (facies Dms) in association with laminated silt and sand (facies FI).
Facies FI contains 0.5 to 2 cm thick lenses of coarse sand to grit throughout. Units 1 through 4 are believed to represent a debris flow dominated proximal braided stream sequence (facies association 1). Units 5 through 7 are composed of poorly-sorted, clast- supported, pebble-cobble diamicts. Unit 5 contains organics in the form of woody debris. Dms
Grn
Thickness (m) Dms
Facies Association 5 Aeolian-Colluvial Units 5,6 and 7.
Facies Association 1 ProxirnaI Braided Units 1,2,3 and 4.
G SM
+ 30.5 rn to bedrock
Figure 8.2 1 :Vertical logged section of LW-97-08 on the left-limit of Haggart Creek downstream of Platinum Gulch. Wood from unit 5 yielded a radiocarbon age of 7970 + 60 BP (Beta- 109 15 1). Units 5
through 7 are interpreted as Holocene colluvium.
Section LW-97-0 1 is located approximately 70 m downstream of section LW-97-
08. A photo of section LW-97-01 is shown in figure 5.22 and the vertical logged section
is shown in figure 8.23. Unit 1 consists of a very-poorly-sorted, matrix-supported,
cobble-boulder diamict (facies Drns) in contact with bedrock. Clasts are angular to
subrounded, with most of the angular clasts concentrated at the base of the unit. Angular
clasts at the base of the unit appear to represent locally derived ripped-up bedrock. The
matrix of unit 1 is clay-rich and has a distinct metallic grey colour. Unit 1 is not laterally
continuous and is interpreted as a local side-valley debris flow. The clay-rich content of
the matrix and distinct metallic grey colour may be due to the incorporation of heavily decomposed local bedrock (schist and phyllite) into the debris flow. Unit 1 represents the richest pay source within this section, however, gold has been found in lesser amounts in unit 2.
Units 2 through 4 consist predominantly of massive to weakly imbricated, clast- supported, pebble-cobble gravel (facies Gm) in association with thinner beds of planar tabular crossbedded sand and pebbly sand (facies Sp). Clasts are subangular to subrounded. Units 2 through 4 are believed to have been deposited in a proximal braided stream environment (facies association 1). Unit 5 is comprised of a poorly-sorted, matrix-supported, pebble-cobble diamict (facies Drns). Unit 5 is interpreted as recent
Holocene coiIuvium. Figure 8.22: Photo of section LW-97-01 on the left-limit of Haggart Creek downstream of Platinum Gulch. Measured section is approximately 32 m thick. Facies Association 1 Facies Association 5 Bedrock Proximal Braided Aeolian-Colluvial Units 1,2,3 and 4. Unit 5.
Figure 8.23:Verticai logged section of LW-97-01 on the left-limit of Haggart Creek downstream of Platinum Gulch. Section LW-97-03 is located approximately 130 m downstream of section LW-
97-01. The vertical logged section is shown in figure 8.24. Units 1 through 4 are
composed of massive to crudely stratified pebble-cobble gravel (facies Gm), trough
crossbedded gravel (facies G t) and horizontally stratified to trough-crossbedded sand and
pebbly sand (facies Sh and St respectively). Units 1 through 4 are believed to have been
deposited in a medial to distal braided stream environment (facies association 2). Figure
5.25 is a photo taken adjacent to section LW-97-03 and shows a typical medial to distal
braided stream sequence. Units 5 through 7 consist of poorly-sorted, matrix-supported,
granule to pebble diarnict (facies Dms) in association with organic-rich, laminated fine
sand to clay (facies FI). Facies F1 contains scattered pebbles and thin gritty lenses
throughout. Units 5 through 7 are interpreted as colluviurn.
Section LW-97-02 is located approximately 130 m downstream of section LW-
97-03. A photo of section LW-97-02 is shown in figure 8.26 and the vertical logged section is shown in figure 8.27. Unit 1 consists of massive to crudely stratified, matrix- to clast-supported, pebble-cobble gravel (facies Gm) in association with horizontally stratified to trough-crossbedded sand to pebbly sand (facies Sh and St respectively). Unit
I is interpreted as a medial to distal braided stream sequence (facies association 2). Unit
2 consists of a moderately-sorted, imbricated, clast-supported, pebble-cobble gravel with minor boulders (facies Grn). Clasts of unit 2 are subangular to rounded; matrix is predominantly coarse sand to grit. Unit 2 is laterally continuous and can be traced as far as 140 m downstream. Unit 2 is interpreted as a channel deposit of a wandering gravel bed sequence (facies association 3). Unit 3 consists of poorly-sorted, massive to G SM Figure 8.24:Vertical logged section of LW-97-03 on the left-limit of Haggart Creek downstream of P!atinurn Gulch. Figure 8.25: Photo taken adjacent to section LW-97-03on the left-limit of Haggart Creek showing typical medial to distal braided sequence (facies association 2). Exposed section measures approximately 24 m thick. Figure 8.26: Photo of section LW-97-02on the ieRlimit of Haggart Creek, downstream of Platinum Gulch. Measured section is approximately 13 m thick. Figure 8.27: Vertical logged section of LW-97-02 on the left-limit of Haggart Creek downstream of Platinum Gulch. laminated fme sand lo silt with minor pebbles and gritty lenses throughout (facies Fl).
Unit 3 is organic-rich and is interpreted as colluvium.
Section LW-97-05 is located approximately 140 rn downstream of section LW-
97-02. A photo of section LW-97-05 is shown in figure 8.28 and the vertical logged
section is shown in figure 8.29. Units 1 through 5 consist predominantly of crudely stratified, clast-supported, granule-pebble to pebble-cobble gravel (facies Grn) in association with horizontally stratified to rippled sand (facies Sh and Sr respectively); laminated sand to silt (facies F1) occur with facies Sh. Units 1 through 5 are believed to represent a medial to distal braided stream sequence. Unit 6 consists of a moderately- sorted, clast-supported, pebble-cobble gravel with minor boulders (facies Gm). Clasts are subangular to rounded. Unit 6 of section LW-97-05 can be correlated with unit 1 of section LW-97-02 and is interpreted as a channel deposit of a wandering gravel bed sequence (see discussion above of unit 2, section LW-97-02).
Unit 7 consists of interbedded/intentratified organic-rich silty clay (facies Fl) with poorly-sorted, matrix-supported, pebble-diarnict (Dms). Facies Dms is weakly stratified and clasts are slightly aligned parallel to slope. Clasts are angular to subangular. Wood was sampled at 0.5 m and 2.45 rn from the base of unit 7; radiocarbon ages are 8 170 + 80 BP (Beta- 109146) and 7600 2 80 BP (Beta- 109 147) respectively.
Unit 7 is interpreted as early Holocene colluvium. Unit 8 is similar to unit 7, however unit 8 lacks organic-rich silt. The contact between unit 7 and unit 8 is gradational. Unit 8 is interpreted as recent colluvium. Figure 8.28: Photo of section LW-97-05 on the left-limit of Haggart Creek downstream of Platinum Gulch. Measured section is approximately 13.5 rn thick. Dms
Fl Dms
Thicknes Dms/Fi (m)
Facies Association 5 Aeolian-Colluvial Units 7 and 8
Facies Association 3 Wandering Gravel Bed Unit 6
Facies Association 2 Medial to Distal Braided Stream; Units 1 - 5.
Figure 8.29: Vertical logged section of LW-97-05 on the left-limit of Haggart Creek downstream of Platinum Gulch. 8.2.5 Haggart Creek (right-limit near 15 Pup)
Section LW-97-24 is the furthest upstream of the sections measured on the right-
limit of Haggart Creek near 15 Pup. Section LW-97-24 is located approximately 1.8 km
downstream of the confluence of Gill Gulch with Haggart Creek (figure 4.1). The
vertical logged section of LW-97-24 is shown in figure 8.30. Unit 1 consists of massive
silt and clay with fme sand to pebble stringers throughout (facies FI), grading into weakly
laminated fine sand to pebbly sand (facies Sh) and fmally a moderately-sorted, matrix- supported, pebble diamict (facies Dms). Facies Dms of unit 1 is weakly stratified and contains angular to subrounded cfasts. Unit 4 consists of interbeddedlinterlaminated silt and fine sand (minor clay laminae) with 2 to 5 cm thick lenses of granule to pebble gravel. Units I through 4 contain organics in the form of small twigs (< 2 cm) and organic-rich silt. Unit 5 is composed of a massive, poorly-sorted, matrix-supported. pebble-cobble dimict. Clasts are angular to subrounded. All units of section LW-97-24 are moderately to heavily cryoturbated. Section LW-97-24 is interpreted as recent
Holocene colluvium.
Section LW-97-25 is located approximately 30 rn downstream of section LW-97-
24 and is shown in figure 8.3 1. The vertical logged section of LW-97-25 is shown in figure 8.32. Unit 1 consists of large-scale planar tabular crossbedded gravel and pebble sand (facies Gp and Sp respectively). Individual beds are moderately to well stratified and range in thickness between 10 and 30 cm. Dip on foresets is approximately 20 degrees. Unit 1 is interpreted as a longitudinal bar deposit in the downstream reach of paleo-Haggart Creek (facies association 2, medial to distal braided stream). Dms
F 1
Thickness 10.9% Facies Association 5 (m) Aeolian-Colluvial
Dms
Dms Sh F1 Covered
Figure 8.30: Vertical logged section of LW-97-24 on the right-limit of Haggart Creek near 15 Pup. Figure 8.3 1: Photo of section LW-97-25on the right-limit of Haggart Creek near 15 Pup. Pogo measures 1 .Z5m. Facies Association 2 Medial to Distal Braided Stream
Facies Association 3 Wandering Gravel Bed Thickness (m)
Facies Association 2 Medial to Distal Braided Stream
G SM
Approx. 2 m to bedrock
Figure 8.32: Vertical logged section of LW-97-25 on the right-limit of Haggart Creek near 15 Pup. Unit 2 of section LW-97-25 consists of moderately-sorted, clast-supported,
pebble-cobble gravel (facies Gm); clasts are subangular to rounded. Unit 2 forms an
erosional contact with underlying unit 1 as is shown by the truncated planar tabular
crossbeds of unit 1 (see figure 8.3 1). Unit 2 is stratified and moderately imbricated.
Fabric was measured on unit 2 and was found to have a strong a-axis imbrication perpendicuiar to paleoflow. The paleoflow direction was measured at approximately 185 degrees. Unit 2 is laterally continuous and can be traced downstream over 150 m. Unit 2 is interpreted as channel gravel of a wandering gravel bed sequence (facies association 3).
Unit 3 consists of horizontally stratified to laminated silt to fine sand and pebbly sand (facies FI, Sh), in association with crudely stratified, clast-supported, granule to pebble gravel (facies Gm). Facies Grn forms small discontinuous channels, or cut-and- fill structures. Unit 3 is interpreted to represent a braided reach of the wandering gravel bed sequence and is believed to have been deposited as the main channel migrated to the opposite side of the valley. Overlying Unit 3 is slumped debris of organic-rich silt to fine sand and pebbly sand and is interpreted to represent colluvium.
Section LW-97-26 is located approximately 100 m downstream of section
LW-97-25. The vertical logged section of LW-97-16is shown in figure 8.33. Unit I is in contact with bedrock and consists of moderately-sorted, clast-supported, pebble-cobble gravel with isolated boulders (facies Gm). Clasts are subangular to rounded. Gravel of unit I is moderately to strongly imbricated. Within unit 1 are pods of organic-rich silt and woody debris (figure 8.34). Wood was sampled approximately 30 cm below the upper contact of unit I and yielded a radiocarbon age of 6040 f 70 BP (Beta- 1 1 1605). Facies Association 5 Aeolian-Colluvial Fac ies Association 2 Medial to Distal Braided Stream
Fac ies Association 3 Thickness Wandering Gravel (m) Bed
Figure 8.33: Vertical logged section of LW-97-26 on the right-limit of Haggart Creek near 15 Pup. Figure 8.34: Photo of imbricated pebble-cobble gravel of unit 1 of section LW-97-26on the right-limit of Haggart Creek near 15 Pup. Piece of wood in photo yielded a radiocarbon age of 6040 6 70 BP. The organics are believed to represent caved-in riverbank deposits formed as paleo-
Haggart Creek cut into the side valley.
Unit 2 consists of horizontally stratified to laminated silt to fine sand and pebbly
sand (facies F1, Sh), in association with crudely stratified, clast-supported granule
topebble gravel (facies Gm). Facies Gm forms small discontinuous channels, or cut-and-
till structures. Unit I is interpreted to represent a channel gravel from a wandering gravel bed sequence. while unit 2 is interpreted to represent a braided reach of a wandering gravel bed sequence. Unit 3 of section LW-97-26 consists of very poorly-sorted, matrix- supported, pebble diamict. Clasts are angular to subangular and the matrix is silt rich.
Unit 3 is organic rich and contains small pieces of woody debris throughout. Unit 3 is interpreted as Holocene colluvium.
Section LW-97-27 is located approximately 50 m from section LW-97-26.
Bedrock drops off at this location, resulting in a thicker package of exposed sediments
(figure 8.35). The vertical logged section is shown in figure 8.36. Unit 1 is in contact with bedrock and is composed of a very poorly-sorted, matrix-to clast-supported, pebble cobble diarnict (facies Dms). Clasts are predominantly angular to subangular and the matrix is clay-rich. The colour of unit 1 is metallic grey. The clay-rich content of the matrix and the metallic grey colour of the unit is likely due to the incorporation of decomposed bedrock of schist and phyllite. Fabric measured on this unit was highly scattered. Unit 1 is interpreted as a side-valley debris flow. Unit 1 represents the pay unit at this location.
Unit 2 is composed of stratified sand and pebbly sand (facies Sh) with small channel fill structures of granule to pebble gravel (facies Gm). Parts of unit 2 display Figure 8.35: Photo of section LW-97-27 on the right-limit of Haggart Creek near 15 Pup. View is looking upstream on Haggart Creek. Pogo measures 1.25 m. Facies Association 5 Dms Aeolian-Colluvial Facies Association 2 Gm/S h Medial to Distal Braided Stream
Facies Association 3 Gm Wandering Gravel Bed
1 70. Thickness (m) 3.85- Facies Association 2 Gm/S h Medial to Distal Braided Stream
S ide-valley debris Dms flow
Figure 8.36: Vertical logged section of LW-97-27 on the right-limit of Haggart Creek near 15 Pup. weakly developed, very shallow dipping (< 20 degrees) planar tabular crossbeds. Unit 2
has similar characteristics to unit 1 of section LW-97-25 and is interpreted as a medial to
distal braided stream sequence (facies association 2).
Unit 3 consists of a moderately-soned, clast-supported, pebble-cobble gravel with
isolated boulders (facies Gm). Clasts are subangular to rounded. Unit 3 contains pods of
organic-rich silt, which may or may not include pieces of woody debris. Unit 3 is
moderately to strongly imbricated with a-axes oriented perpendicular to paleoflow.
Paleoflow direction was measured to be approximately 170 degrees. Unit 3 is interpreted to represent a channel of a wandering gravel bed sequence (facies association 3).
Unit 4 is composed of horizontally stratified to laminated silt to tine sand and pebbly sand (facies FI, Sh), in association with crudely stratified, clast-supported granule to pebble gravel (facies Gm). Facies Gm forms small discontinuous channels, or cut-and- fill structures. Unit 4 is believed to represent a braided reach of a wandering gravel bed sequence (facies association 3).
Unit 5 is consists of a very poorly-sorted, matrix-supported, pebble-cobble diamict. Clasts are angular to subangular and matrix is predominantly fme sand to silt.
Unit 5 is organic-rich and contains woody debris throughout. Unit 5 is interpreted as recent Holocene colluvium.
8.3 Schematic Profdes and Lateral Relationships
8.3.1 Dublin Gulch
A stratigraphic correlation of Dublin Gulch is shown in figure 8.37 (in pocket).
Correlation was completed using elevation above sea level as a datum. The oldest unit exposed at Dublin Gulch is a pre-Reid debris flow; it may have resulted &om the onset of Reid glaciation. Stratigraphically above this debris flow lies a deposit of Reid basal till.
Exposed in section LW-97-23 is a unit of Reid glaciofluvial outwash, which was likely
deposited as Reid ice retreated from Haggart Creek valley. This unit was interpreted as
glaciofluvial outwash based on a paleoflow direction which was measured to be due
north, or up-valley. This paleoflow direction, which is up-gradient, could have only
resulted From a glaciofluvid outwash deposit as ice retreated from Haggart Creek valley.
Upstream exposed in section LW-97-21 is a thick sequence of proximal alluvial
fan deposits. There is no dating control in this section, however, based on its
stratigraphic position and the thickness of the package, sediments of section LW-97-2 I
have been interpreted as part of a 1McComell periglacial fan sequence.
8.3.2 Haggart Creek (right-limit near Gill Gulch)
A stratigraphic correlation of Haggart Creek near Gill Gulch is shown in figure
8.38 (in pocket). Correlation was based on lithology and facies associations. Some age
control was achieved from a date obtained from section LW-97- LO. The oldest units
exposed represent a sequence of braided stream sediments of paleo-Haggart Creek
(sections LW-97-14 and GILL3). Paleo-Haggart Creek is believed to have reworked the
toe of a McComell-age periglacial fan, which originated form Gill Gulch. The timing of
the reworking of the periglacial fan is uncertain, but is presumed to be post-McConneli.
As the climate warmed during post-McConnell time, it is likely that the development of
Gill Gulch periglacial fan waned, allowing paieo Haggart Creek to rework the toe of the
fan.
Exposed in sections LW-97- 10 and GILL4 are alluvial gravels of a wandering gravel bed sequence. In both cases, the alluvial gravel lies directly on bedrock and represents a period of downcutting and incision. A radiocarbon date from colluviated
organic-rich silts above this sequence confirms that these sediments predate 12,3 10 BP.
It is believed that the wandering gravel bed sequence is post-McConnell in age. It is
assumed that this wandering gravel bed river downcut during post-McConnell time in
response to base-level changes as McComell ice retreated from Lynx valley.
Exposed in sections LW-97- 10, LW-97- 1 1 and GILL4 are organic-rich silts,
which are interpreted as Holocene age colluvium. These sediments have similar
characteristics to the "black mucks7'of the Klondike region. Froese (1997) has
interpreted the development of "mucks" as a hillslope response to cooling, or reworking
of older loess-like deposits. During post-McConnell time, it is likely that loess blanketed
the slopes of the study area and therefore may be a contributing factor to the high silt
content of the colluvium. Slow revegetation of the slopes during post-McConnell time
would have also left the slopes relatively unstable, resulting in active colluviation.
8.3.3 Haggart Creek (left-limit, downstream of Gill Gulch and Platinum Gulch)
Exposures on the left-limit of Haggart Creek display similar facies associations to
those found on the right-limit of Haggart Creek near Gill Gulch. A stratigraphic correlation of Haggart Creek downstream of Platinum Gulch is shown in figure 8.39 (in pocket). The oldest sediments exposed in this area are believed to be McComell-age periglacial sediments of paleo-Haggart Creek. These sediments are exposed in all sections along the left-limit of Haggart Creek and are represented by a lateral facies change tiom a proximal braided stream sequence (sections LW-97-15, -08 and -01) to a medial to distal braided stream sequence (sections LW-97-03,-02 and -05). The large sediment source on the Iefi-limit of Haggart Creek is believed to have been the Platinum
Gulch periglacial fan (McConnell-age). Stratigraphically overlying the McComelI-age
braided sediments is a paleo-Haggart Creek wandering gravel bed sequence. This
sequence underlies colluviated organic-rich silts of Holocene age. It is believed that the package of wandering gravel bed sediments and overlying colluviated organics on the left-limit can be correlated with the same package on the right-limit of Haggart Creek near Gill Gulch.
The wandering gravel bed sequence is not seen in the upstream sections of the left-limit of Haggart Creek (see sections LW-97- 15, -08, -0 1 and -03 of figure 8.39). It is believed that a large periglacial fan originating from Platinum Gulch would have diverted the main channel to the opposite side of the valley. Therefore, the deposition of proximal braided stream sediments exposed in the uppermost units of sections L W-97- 15. -08,-0 1 and -03 was most likely penecontemporaneous with the deposition of post-McCo~ell wandering gravel bed sediments observed in other parts of Haggart Creek valley.
83.4 Haggart Creek (right-limit near 15 Pup)
A stratigraphic correlation of Haggart Creek downstream of 15 Pup is shown in figure 8.40 (in pocket). These sections are believed to correlate with exposed sections upstream on the right-limit of Haggart Creek near Gill Gulch, as well as across the valley with exposures on the left-limit of Haggart Creek. All sections on the right-limit of
Haggart Creek near 15 Pup contain a package of post-McConnell wandering gravel bed sediments. At section LW-97-26 alluvial gravel of the wandering gravel bed sequence was observed to be in contact with bedrock. It is believed that this wandering gravel bed river downcut to bedrock at this location, leaving behind an alluvial terrace. Downstream at section LW-97-27, a relatively thick package of sediment is
exposed showing underlying older (McComell-age) medial to distal braided sediments.
These braided sediments are also exposed at section LW-97-25 in the form of a
longitudinal bar sequence with large-scale planar tabular crossbeds. Wood smpled from
alluvial gravel of a wandering gravel bed river underlying organic-rich silt (colluvium),
yielded a radiocarbon age of 6040 + 70 BP. This date confirms that active hillslope
colluviation of organic-rich silt still persisted on the right-limit of Haggart Creek near 15
Pup well into Holocene time.
8.4 Paleogeographic Reconstruction
8.4.1 Introduction
The paleogeographic history of Haggart Creek study area is shown in figures 8.41
to 8.45. These figures were based on surficial geology, field relationships and facies
associations data tiom logged vertical sections within the basin.
8.4.2 Discussion
Prior to the onset of glaciations in Quaternary time, Tertiary time was
characterized by a prolonged period of weathering and erosion. The climate at this time
has been described as a tropical humid environment, resulting in prolonged weathering of
the bedrock to depths of several tens of metres (Boyle, 1979). This environment would
have been ideal for the formation of placer gold deposits provided a local lode gold
source existed. Weathering of auriferous sulphides and supergene enrichment fiom the
Dublin Gulch granodiorite stock and local quartz-sulphide-gold veins produced placer gold deposits within the Haggart Creek study area. Supergene enrichment is a near- surface process of mineral deposition in which oxidation produces acidic solutions that
leach metals and carry them downward and repricipitate them, leaving behind an enriched
deposit (Eyles and Kocsis, 1988). Placer gold deposits were initially in the form of
eluvial placers, were subsequently reworked downslope into colluvial placers and then
finally introduced and reconcentrated in the streams as alluvial placers.
Glaciation began with the onset of the Pre-Reid multiple glacial events. The fmt
of these glaciations occurred at least 2.58 Ma ago (Froese, L997). As many as five pre-
Reid glacial events have been recorded in the Mackenzie Mountains, Northwest
Territories (Duk-Rodkin, et al., 1996). Haggart Creek study area lies within the pre-Reid
glacial limits. Pre-Reid ice is believed to have topped Potato Hills near Dublin Gulch;
evidence of this is shown by the presence of scattered pre-Reid glacial erratics found on
Haggart Dome and Potato Hills at an elevation of 4900 feet a.s.1. (Bond, 1997b). No pre-
Reid glacial sediments have been documented in the main valleys of the study area.
Following the multiple pre-Reid glacial events there existed another extended
warm period known as the pre-Reid interglacial. The nature of soils developed at this
time (luvisols) suggests that pedogenesis occurred over a long period of time. Evidence
of strong alteration and weathering suggest a truly temperate climate, warmer than what
we see in the Yukon today (Tmocai. et id., 1985). A warm temperate climate at this
time would have been conducive to the formation of new eluvial and colluvial placer gold deposits on the slopes, as well as the reworking and reconcentrating of previously formed alluvial placers in the main valleys subsequent to the erosion of pre-Reid glacial deposits.
Pre-Reid interglacial sediments were documented in a unit below a Reid basal till in an exposure on the right-limit of Dublin Gulch. The unit was interpreted as a side-valley debris flow and wood from this unit yielded a C-14 date of greater than 37,740 BP (Beta-
1 1 1603).
Following the pre-Reid interglacial, another major cooling event resulted in the onset of
the Reid glacial episode. The Reid glaciation is at least 200 ka old. Berger (1994)
provides a thermoluminescence date of loess bracketing the Sheep Creek tephra at
Fairbanks, Alaska. This tephra was also documented above Reid glacial outwash in an
exposed section along the Stewart River, central Yukon. Haggart Creek study area again
Lies within the Reid glacial limits. Ice from the Reid glaciation represents the last ice
sheet to have advanced up Haggart Creek valley. Lynx and lower Haggart Creek valleys
were the main conduits for ice advancing through the study area and this is emphasized
by the broad U-shaped morphology of each of these valleys (figure 3.3). Reid ice flowed
down Lynx Creek valley and continued down lower Haggart Creek and eventually into
the South McQuesten valley. At this time, ice thickened and advanced into upper
Haggart Creek valley. Reid ice is believed to have reached elevations of 3600 feet a.s.1.
(figure 8.41) as is shown by the presence of Reid erratics found on Potato Hills at this elevation (Bond, 1997b). As ice advanced upper Haggart Creek valley, it is likely that damming occurred, resulting in the formation of a proglacial lake, which would have buried pre-Reid interglacial sediments in the main valley. Reid ice would have advanced further up the valley, depositing a basal till sequence. Preservation of Reid glacial sediments in the study area today exists as discontinuous Reid terraces along the left-limit of Haggart Creek at approximately 2700 to 2800 feet a.s.1. (present-day valley bottom is at approximately 2500 feet a.s.1.) and a Reid till exposure along the left-limit of Dublin
Gulch. No Reid glaciolacustrine sediments are exposed in the main valleys today.
It is important to note here that Haggart Creek having a north-south orientation,
lies transverse to regional ice-flow patterns, which is southwest in the study area (down
Lynx Creek and lower Haggart Creek; see tigure 3.3). The orientation of Haggart Creek transverse to paleo ice-flow meant that any ice advancing up the valley (up-gradient) would have had relatively little scouring and erosional affects, thereby burying and essentially preserving placer gold deposits formed during interglacial times. This affect would have been similar during the pre-Reid glacial events, as it presumed that regional ice flow patterns followed the same path as during Reid time, since the ice flow is predominantly topographically controlled (Bond, 1999, pers. cornm.).
Another period of climatic warming followed the Reid glaciation and is termed the Koy-Yukon interglacial event (figure 8.42). The Koy-Yukon interglacial event resulted in the formation of brunisolic soils, which suggests a less temperate climatic condition compared to the pre-Reid interglacial (Tamocai, et al., 1985). Some Koy-
Yukon soils have been compared to luvisols found in more southern bored regions of
Canada today (Tamocai, et al., 1985). Following deglaciation, streams in the area would have downcut through Reid glacial sediments in response to base level change, leaving behind Reid glacial terraces along the left-limit of Haggart Creek (figure 8.42).
Interglacial streams presumably reached bedrock some time during the intergiacial, resulting in the reworking and reconcentration of pre-existing placer deposits. At the same time, weathering of local bedrock lode sources may have liberated more gold into the system. No Koy-Yukon interglacial sediments were documented in the study area. 2.5'" MZ E 2d 2L.S 4) ox 232 u 2 0 5MTr: 56 ga 2 z;"o 2 g -* -* -w cu .= = 3 p2s 95% 22 w= CG cp .I .- E .5 2 xu2Ox- 3 2 0 0 &** " qs03s 5.29 'Z s 2-F3 *-L FA ===0" l-, 3 0- g.32Q) - 0 2 Ti c 3 raeegs Y 2 1 x-0 ecS2 0 c SD CYS .3-w.S .5 - j 3 $=.a ,-0 5 ag~:n E= i$p.3 0 222 n .d m 0.- Zd 2 9 0 20.g 4, r E!= 0 2 '5% "2 C E.P '3 W 1.2s 0 25 M,za c *y & AS c) a 0 c.-nos a -0%3 5.5 LU a0 The McCo~ellglacial event represents the most recent and last glacial event to
have affected the Yukon. Organic-rich alluvium below McConnell till was observed in
an exposed section at the Mayo Indian Village on the Stewart River near Mayo, central
Yukon. Seeds from the organic rich alluvium were dated by radiocarbon methods and
confirm the McConnell glaciation to be at least 29.6 ka (Giles, 1993). Pollen and fossil plant analysis from detrital organics within the same section indicate an essentially treeless environment, suggesting that a cold climate due to the McConnell glaciation had already set in some time before 29.6 ka (Matthews et al., 1990).
Haggart Creek lies just outside the McConnell glacial limits. The McComell glaciation terminated in Lynx Creek approximately I 1 krn east of the confluence between
Lynx Creek and Haggart Creek (figure 3.3). No part of Haggart Creek was directly affected by McConnell ice, however it was greatly affected by the cold climate induced by the McConnell glaciation and felt the affects of a periglacial environment. A rising base level resulted in extensive aggradation in Haggart Creek valley and its tributary valleys. Steep, bare slopes lacking in vegetation would have been favourable to the production of loose debris by rapid weathering and also promote the rapid reworking of all available material (Ryder, 197 1). Aggradation in Haggart Creek was due to the build- up and progradation of alluvial fans from tributaries into its valley. It is presumed that
Fisher Gulch, Dublin Gulch, Gill Gulch, and Platinum Gulch would have all developed extensive periglacid fans during McCo~elltime (figure 8.43). As a result of large inputs of sediment into the main valley, Haggart Creek is presumed to have had a classic braided stream character (figure 8.43). Braided sediments are exposed in the lowermost parts of all sections on Haggart Creek, from its left-limit, to its right-limit and are
believed to have infilled the basin during the early McConnell to post McConnell time.
Haggart Creek would have likely reworked older auriferous interglacial gravel into the
McConnel-aged braided sediments.
The timing of the McConnell deglaciation is uncertain, however it is presumed
that the periglacial environment in Haggart Creek study area had waned by at least
12,3 10 years B.P. as there is evidence that downcutting had already begun prior to this
time. Wood was sampled from colluviated organics at the contact with an alluvial terrace
gravel on Haggart Creek near Gill Gulch. The wood was C- 14 dated at 12,3 10 + 120 BP
(Beta- 109 150). The alluvial terrace gravel below the organics 1ies directly on bedrock.
The alluvial terrace gravel has been interpreted as part of a wandering gravel bed
sequence and represents the downcutting stage of the post-McCo~elldeglaciation in
response to base-level change. Therefore, it is believed that some time prior to
approximately 12,000 years B.P., Haggart Creek had evolved from an aggrading braided
stream system, to a wandering gravel bed stream, which downcut through the underlying
braided sediments and in places reached bedrock (figure 8.44).
During late McConnell time, while streams were downcutting, side valley slopes
still remained active as is shown by colluviated organics, which buried main valley
alluvium (e.g. organic-rich silt above alluvial terrace on Haggart Creek near Gill Gulch).
These organic-rich silts have similar characteristics to the "black mucks" of the Klondike area, central Yukon. Froese (1 997) has interpreted these "black mucks" as possibly representing a hillslope response to cooling, or reworlung of older loess-like deposits.
Loess has been documented in the study area and it is possible that loess deposits
blanketed the slopes some time during the McConnell. Revegetation of the slopes during
the post-McConnell would have presumably taken some time, resulting in
the instability of slopes and active colluviation. Permafrost, which exists on east-
facing slopes of the study area today would have likely also existed during post-
Mccomefi and early Holocene time. Seasonal thawing of ice fiom permafrost would
have been another factor contributing to colluviation of the slopes at that time. These
organics have been dated in several areas within Haggart Creek and range fiom as old as
12,3 10 B.P. on the upstream end (near Gill Gulch), to 8 170 + 80 B.P. (Beta- 109 146) in
the midstream reach, to younger than 6040 + 70 B.P. on the downstream reach on the
right-limit. Ritchie (1982) documents increased organic sedimentation at 12 000 B.P. in
the Doll Creek area, North Yukon as a result of a rapid transition from a warming glacial
to non-glacial period. Pollen records in the same area also show that a well-developed
spruce forest had developed in the area by 7500 B.P. If vegetation records were
comparable in the Haggart Creek area to those found in northern Yukon, it is probable
that the youngest organics on the right-limit of Haggart Creek are more likely related to
slope aspect and permafrost, rather than slope instability due to a lack of vegetation. That
is, the east-facing slopes, which are rich in permafrost, would have undergone active colluviation due to seasonal melting of the active layer. Similar processes occur on permafrost-rich slopes within the study area today. Colluviation of the organic-rich silts on the side valleys may potentially bury and preserve alluviai placers as is shown on
Haggart Creek near Gill Gulch (see figure 8.1 1). '(~t7.8
adg) Xepo1 qaal3 -38~~U! aas am aqy qsnu wa4s 8uuapurratu pauguos E olu!
padola~ap611et4uana amq plnoM yaaJ3 ueZ8c~ aua~ologaq, 8upnp qod awos
JV -qsodap ploS laqdauaDoloH ~uasa~aJom olu! paIenua9uosaJ pw payJon\aJ uaaq
aJojaJav seq 'p108 ~aqdpauyuos amq LEU q3!4~'[~AEJ~ lqAn[le laplo r(uv *la~ea
le!An[@ -laplojo By~~ass!ppm 8qun3u~oplayuy u! paqnsaJ amq Asp luasa~datpol uo!y!3~18ilauuopn aqjo pua aw UIOJ. s[aAal aseq lqddorp pw uo!le!3elfaaa
CHAPTER 9 - CONCLUSIONS
9.1 Conclusions
The following chapter is a summary of research results. Section 9.1.1 summarizes the sedimentology and stratigraphy of Haggart Creek study area with reference to paleogeographic setting. Section 9.1.2 summarizes the placer gold settings within the study area.
9.1.1 Summary of Sedimentology and Stratigraphy
The oldest sediment exposed in the study area represents a pre-Reid debris flow located on the left-limit of Dublin Gulch. This debris tlow is believed to have resulted from the onset of Reid glaciation.
Reid-age sediments were documented at two sites within the study area. The first site is located on the left-limit of Dublin Gulch and represents and older unit of Reid-age basal till. The second site is also located on the left-limit of Dublin Gulch and represents a younger deposit of post-Reid glaciofluvial outwash. The glacial outwash is believed to have been deposited directly from Reid ice as it retreated from Haggart Creek valley.
The Koy-Yukon interglacial followed the Reid glaciation and was characterized by a warmer and more humid climate than that of today. The Koy-Yukon interglacial resulted in prolonged and extensive weathering of bedrock, likely to depths of several tens of meters. This period was also marked by active downcutting and incision in response to base-level change following the Reid glacial event. No interglacial sediments
(Koy-Yukon)were documented in the study area.
Haggart Creek lies just outside of the McConnell glacial limits. McConnell ice terminated approximately 1 1 kilometres east of the confluence between Lynx Creek and Haggart Creek. Therefore, the study area was influenced by a cold, periglacial environment. McConnell-age sediments exposed in the study area are represented by proximal braided river sequences in the upstream reaches of Haggart Creek, and medial to distal braided river sequences in the downstream reaches of Haggart Creek.
During post-McConnell time, Haggart Creek began to downcut in response to base-level change and evolved into a wandering gravel bed river. In some areas, the wandering gravel bed river was able to downcut through underlying McConnell-age braided sediments and reach bedrock. Sediments of the wandering gravel bed sequence are exposed on both the left-limit and right-limit of Haggart Creek and are represented by coarse, imbricated, channel gravel, as well as braided reaches.
Early Holocene time was marked by a period of active colluviation represented by crganic-rich silts. Revegetation of the slopes during post-McCo~elltime would have presumably taken some time, resulting in the instability of the slopes and active colluviation. These organic-rich silts are believed to be, in part, reworked McConnell- age loess deposits. These deposits are exposed on both the left-limit and right-limit of
Haggart Creek. Wood sampled From underlying alluvium on the right-limit of Haggart
Creek near 15 Pup confirms that active colluviation of organic-rich silt still persisted after
6040 BP,
Deglaciation and dropping base levels from the end of the McCo~ellglaciation to present day has resulted in further downcutting and dissecting of older alluvial deposits. During this time, Haggart Creek is believed to have developed into a confined meandering stream, a morphology similar to that of present-day Haggart Creek. 9.1.2 Summary of Placer Gold Settings
Placer gold occurs in a wide variety of settings within the study urea. In the study area. placer gold occurs within five facies associations and are listed as follows:
I ) Recent gulch deposits found on Fisher Gulch.
2) Proximal braided sediments found on Dublin Gulch. the right-limit of Haggart Creek
near Gill Gulch and the left-limit of Haggan Creek downstream of Platinum Gulch.
3) Medial to distal braided sediments found on the left-limit of Haggan Creek.
downstream of Platinum Gulch and on the right-limit of Haggirt Creek. near 15 Pup.
4) Clay-rich diamicts. which are believed to represent side-valley debris flows that have
reworked underlying decomposed bedrock of schist i~ndphyllite in the main valley.
These deposits are found at two sites: on the left-limit of Haggart Creek. downstream
of Platinum Gulch and on the right-limit of Haggart Creek. near 15 Pup.
5) Relatively coarse alluviiim of a wandering gravel bed channel found on the right-limit
of Haggart Creek. near Gill Gulch and on the right-limit of Haggan Creek. near 15
Pup.
In all of the above cases, the sediments are in contact with bedrock. All of the sediments. with the exception of sediments observed at Fisher Gulch. are presumed to be
McConnell, or post McConnell in age.
It is believed that placer gold deposits were mainly formed during interslacia1 periods. when warm. humid climates resulted in active weathering and release of gold from local bedrock sources. Eluvial placer gold deposits would have been the first placers to form. They would have eventually been introduced into the streams by colluvial processes. Once in the alluvial environment, placer gold was reworked and re- concentrated as rich placer deposits on bedrock.
During the pre-Reid and Reid glnciations. Haggart Creek was exposed to little or no glacial scour and erosion. due to the orientation of Haggan Creek transverse to local ice-flow patterns. Therefore. glacial sediments deposited in Hagpan Creek valley would have buried ilnd preserved underlying auriferous interglacial gravel.
During the McConnell glaciation. ice did not enter the valley. All sediments deposited during McConnell time are all~lvialin origin and would have presumably reworked the underlying. gold-bearing. interglacial gravel.
There are believed to be two main sources of lode gold in the study area. The larger of the two sources occurs on Potato Hills at the headwaters of Dublin Gulch. Gold in this area occurs in sheeted qumz veins within a Late Cretaceous-age granodiori te stock (Dublin Gulch stock). The second source occurs within within quartz-arsenopyrite- pyrite-scorodite-gold veins. These veins are found within and adjacent to the Dublin
Gulch stock. as well as isolated veins in local bedrock along Haggart Creek (see tigure
Gold grain morphology varied widely within the study area however. most gold grains were found to fall in the sub-angular to rounded range. Crystalline to sub- crystalline gold was found on Dublin Gulch and is due to its proximity to the lode source on Potato Hills. Sub-crystalline gold was found on the right-limit of Haggart Creek. near
Gill Gulch and is believed to have originated from nearby quartz-arsenopyrite-pyrite- scorodite-gold veins (see figure 2.5). Fisher Gulch is a right-limit tributary to Haggart Creek and is located approximately 750 rn upstream of the confluence of Dublin Gulch with Haggart Creek.
Placers from Fisher Gulch also contained grains of cryst;illine to sub-crystalline gold. It was believed that gold was transported by Reid ice from Potato Hills to Fisher Gulch.
However. if tnlnsponed by ice. it is hishly unlikely that crystitlline gold would be preserved. Therefore. based on the presence of crystalline gold and the seographic location of Fisher Gulch with respect to Potato Hills and Dublin Gulch. it is believed that
Fisher Gulch contains its own local source of gold. REFERENCES
Armentrout, J.M, 1983. Glacial lithofacies of the Neogene Yakataga Formation, Robinson Mountains, southern Alaska Coast Range, Alaska. 111: Glacial Marine Sedimentation, B.F. Molnia (ed.), Plenum Press, New York, p.629-665.
Barendregt, ROW-,Enkin, R.J-, Duk-Rodkin, A. and Baker, J., 1996. Paleomagnetic evidence for late Cenozoic glaciations in the Mackenzie Mountains of the Northwest Territories. Environment Canada, Atmospheric Environment Service, UDC:55 1.582(7 12) 55 pp.
Berpr, G.W., 1994. -4ge of the Alaska/Yukon Sheep Creek tephn from
thermoluminescence dating of bracketing loess at Fairbanks. " Bridges of the science between North America and the Russian far east". 45'h Arctic Science Conference, 25-27, August, 1994, Anchorage, Alaska - 19 August - 2 September, 1994, Vladivostok, Russia.
Boggs, S. Jr., 1987. Principles of Sedimentology and Stratigraphy, Macmillan Publishing Company, New York, N.Y., 784 pp.
Bond, J.D.9 1997a. The Glacial History and Placer Gold Potential of the North McQuesten River ( 1 16A/ 1 ), Dublin Gulch ( l06D/1) and Keno Hill ( 1 OSM/ I I) Map Areas. Mayo Mining District, Central Yukon. In: Yukon Quaternary Geology, Volume 2, W.P. LeBarge and C.F. Roots (eds.). Exploration and Geological Services Division, Northern Affairs Program, p. 30-43.
Bond, J.D.9 1997b. Surficial geology of Dublin Gulch, central Yukon, NTS 106D/4. Exploration and Geological Services Division, Indian and Northern Affairs, Canada. Geoscience Map 1998-6 (G), 1 :50 000 scale map.
Bond, J.D., 1997~.Late Cenozoic History of McQuesten Map Area Yukon Territory, with Applications to Placer Gold Research. Unpublished MSc Thesis, University of Alberta, Edmonton, Alberta, 16 1 pp.
Bostock, Haso,1948. Physiography of the Canadian Cordillera, with special reference to the area north of the fifty-fifth parallel. Geological Survey of Canada, Memoir 247, 106 pp.
Bostock, HoSm,1966. Notes on glaciation in central Yukon Temtory. Geological Survey of Canada, Paper 65-36, 18 pp.
Bostock, H.S., 1970. Physiographic regions of Canada. Geological survey of Canada. Map 1254A. Boyle, R.W., 1956. Geology and Geochemistry of Silver-Lead-Zinc Deposits of Keno Hill and Sourdough Hill, Yukon Territory. Department of Mines and Technical Surveys. Geological Survey of Canada, Paper 55-30, 78 pp.
Boyle, R. W., 1965. Geology, Geochemistry, and Origin of the Lead-Zinc-Silver Deposits of the Keno Hill-Galena Hill area, Yukon Territory. Department of Mines and Technical Surveys. Geological Survey of Canada, Bulletin 1 1 1,302 pp.
Boyle, R.W., 1979. The Geochemistry of Gold and its Deposits (together with a chapter on geochemical prospecting for the element). Energy Mines and Resources, Geological Survey of Canada, Bulletin 280, 584 pp.
Boyle, R.W., fllsley, C.T. and Green, R.N., 1955. Geochemical Investigations of the Heavy Metal Content of Stream and Spring Waters in the Keno Hill-Galena Hill area, Yukon Territory. Department of Mines and Technical Surveys. Geological Survey of Canada, Bulletin 32, 34 pp.
Burn, C.R., 1987. Notes on features visible from the highway between Stewart Crossing and Mayo. In: Guidebook to Quaternary Research in Yukon. S.R. Morison and C.A.S. Smith (eds.), XI1 INQUA Congress, Ottawa, Canada. National Research Council of Canada, Ottawa, 40 pp.
Chmey, E.S. and Patton, T.S., 1967. Origin of the bedrock values of placer deposits. Economic Geology, v. 62, p. 852-853.
Church, M., 1983. Pattern of instability in a wandering gravel bed channel, br Collinson, J.D. and Lewin, J., rds., Modem and Ancient Fluvial Systems: International Association of Sedimentologists, Special Publication 6, p. 169- 180.
Clayton, J.S., Ehrlich, W.A., Cann, D.B., Day, J.H. and Marshall, I.B., 1977. Soils of Canada. Canada Department of Agriculture, v. 1, 243 pp.
Coney, P.J., 1989. Structural aspects of suspect terranes and accretionary tectonics in western North America. Journal of Structural Geology, v. 1 1, No. 1/2, p. 107- 125.
Coney, P.J., Jones, D.L. and Monger, J.W.H., 1980. Cordilleran suspect terranes. Nature, v. 288, p. 329-333.
Desloges R.J., and Church, M., 1987. Channel and floodplain facies in a wandering gravel bed river, in Ethridge, F.G., Flores, R.M., and Harvey, M.D., eds., Society of Economic Paleontologists and Mineralogists, Special Publication 39, v. 39, , p 99- 110.
Duk-Rodkin, A., 1996. Surficial geology, Dawson, Yukon Territory. Geological Survey of Canada, Open File 3288, scale 1: 250 000 with marginal notes. Duk-Rodkin, A. and Froese, D., 1995. Origin and extent of drift cover, northwestern Canada. Poster presented at the Cordilleran Roundup, Vancouver, British Columbia, February, 1995.
Duk-Rodkin, A., Barendregt, R.W., Tarnocai, C. and Phillips, F.M., 1996. Late Tertiary to Late Quaternary record in the Mackenzie Mountains, Northwest Territories, Canada: stratigraphy, paleosols, paleornagnetism, and chlorine-36. Canadian Journal of Earth Sciences, v. 33, p. 875-595.
Duk-Rodkin, A, Bond, J., Jackson, L.E. Jr. and Barendreght, R.W., 1995. Mid to Late Cenozoic record of glaciations in the northern Canadian Cordillera. Abstract and poster presented at the Cordilleran Roundup, Vancouver, British Columbia, February 1995.
Eyles, N, Eyles, C.H. and Miall A.D., 1983. Lithofacies types and vertical profile models; an alternative approach to the description and environmental interpretation of glacial diarnict and diamictite sequences. Sedimentology, v. 30, p. 393-4 10.
Eyles, N. and Kocsis, S.P., 1988. Gold placers in Pleistocene glacial deposits; Barkerville, British Columbia, CIM Bulletin, v. 8 1, no. 916, p. 7 1-79.
Froese, D., 1997. Plio-Pleistocene Klondike Terraces. Unpublished MSc Thesis, University of Calgary, Calgary, Alberta, 153 pp.
Gabriesle, H., Monger, J.W.H., Wheeler, J.O. and Yorath, C.J., 199 1. Chapter 2, Part A. Morphological belts, tectonic assemblages and terranes. in Gabrieslr, H. and Yorath, C.J. (eds.), Geology of the Cordilleran Orogen in Canada; Geological Survey of Canada, Geology of Canada, no. 4, p. 15-28.
Giles, T.R., 1993. Quaternary Sedimentology and Stratigraphy of the Mayo Region, Yukon Territory. Unpublished MSc Thesis, University of Alberta, Edmonton, Alberta.
Gleeson, C.F. and Boyle, R.W., 1976. The Hydrogeochemistry of the Keno Hill area, Yukon Territory. Geological Survey of Canada, Paper75-14,22 pp.
Green, L.H., 197 1. Geology of Mayo Lake, Scougale Creek and McQuesten Lake Map- Areas, Yukon Territory. Geological Survey of Canada, Memoir 357.
Harington, C.R., 1996. Pleistocene mammals of Dublin Gulch and the Mayo District, Yukon Territory. In: Palaeoecology and Palaeoenvironments of Late Cenozoic Mammals, K.M. Stewart and K.L. Seymour (eds.), University of Toronto Press, Toronto, Canada, p. 346-374. Hein, F.J. and LeBarge, W.P., 1997. Geologic Setting and Stratigraphic Framework of Placer Deposits, Mayo Area, Yukon. It?: Yukon Quaternary Geology, Volume 2, W.P. LeBarge and C.F. Roots (eds.). Exploration and Geological Services Division, Northern Affairs Program, p. 10-29.
Heginbottom, J.A., Dubreuil, M.A. and Harker, P.A., 1995. Canada - Permafrost. In: National Atlas of Canada, 5Lhedition, National Atlas Information Service, Natural Resources Canada, Ottawa. Plate 2.1, bfCR 4 1 77.
Hein, F.J. and Walker, R.G., 1977. Bar evolution and development of stratification in the gravelly braided Kicking Horse River, B.C. Canadian Journal of Earth Scienccs, v. 14, p. 562-570.
Hitchins, A.C., and Orssich, C.N., 1995. The Eagle zone gold-tungsten sheeted vein porphyry deposit and related mineralization. Dublin Gulch, Yukon Temtory. In: Porphyry Deposits of the Northwestern Cordillera of North America, T.G. Schroeter (ed.). Canadian Institute of Mining, Metallurgy and Petroleum (CIM), Special Volume 46, p. 803-8 10.
Hughes, O.L., 1982. Surficial Geology and Geomorphology, 105M SW, 105M SE, 105M NW, lO5M NE. Four 1 : 100 000 Scale maps with marginal notes. Geological Survey of Canada, maps 1982-1. 1982-3. 1982-4, and 1 982-5.
Hughes, O.L., Campbell. R.B., Muller, J.E. and Wheeler, J.O., 1969. Glacial limits and flow patterns, Yukon Territory, south of 65 degrees north latitude. Geological Survey of Canada, Paper 68-34,9 pp.
Hughes, O.L., Rampton, V.N. and Rutter, N.W., 1972. Quaternary Geology and Geomorphology, Southern and Central Yukon (Northern Canada); XXIV International Geological Congress, Field Excursion Guidebook A 1 1.59 pp.
Hughes, O.L., Rutter, N.W. and Clague, J.J.. 1989. Chapter 1, Yukon Territory, Quaternary Stratigraphy and History, Cordilleran Ice Sheet. in: Quaternary Geology of Canada and Greenland, R.J. Fulton (ed.), Geological Survey of Canada, Geology of Canada, No. 1, p. 58-62.
Hunt, P.A. and Roddick, V.C., 1987. A compilation of K-Ar ages, Report 17. in: Radiogenic and isotopic studies, Report I. Geological Survey of Canada, Paper 1987-2.
Irving, E. and Wynne, P.J., 1992. Paleornagnetism: Review and Tectonic Implications. in: The Cordilleran Orogen in Canada, Decade of North American Geology #4, H. Gabriesle and C.J. Yorath (eds.). Geoscience Canada, v. 16, p. 67-83. Jackson, L.E. Jr., and Harington, R., 199 1. Middle Wisconsinan Mammals, Stratigraphy, and Sedirnentology at the Krtza River Site, Yukon Temtory. Geographie Physique et Quatemaire, v. 45, p. 69-77.
Jackson, L.E. Jr., Barendregt, R.W., Baker, J. and Irving, E., 1996. Early Pleistocene volcanism and glaciation in central Yukon: a new chronology from field studies and paleornagnetism. Canadian Journal of Earth Sciences, v. 33, p. 904-9 16.
Knight, J.B., Mortensen, J.K. and Morison, S.R., 1994. Shape and Composition of Lode and Placer Gold from the Klondike District, Yukon, Canada. Bulletin 3, Exploration and Geological Services Division, Indian and Northern Affairs Canada, Yukon Region, 143 pp.
LeBarge, W.P., 1995. Sedimentology of Placer Gravels near Mt. Nansen, Central Yukon Territory. Unpublished MSc. Thesis, University of Calgary, Calgary, Alberta, 272 PP
LeBarge, W.P., 1996. Sedimentology and Stratigraphy of Duncan Creek Placer Deposits, Mayo. Central Yukon. Yukon Quaternary Geology, v. 1, p. 63-71.
LeBarge, W.P., 1997. Overview of Yukon Placer Geology, Gold Production and Prospects. In: Yukon Quaternary Geology, Volume 3, W.P. LeBarge and C.F. Roots (eds.), Exploration and Geological Services Division, Northern Affain Program, p. 1-9.
Leopold, L.B. and Wolman, M.G., 1957. River channel patterns: straight. meandering and braided. U.S.G.S.Professional Paper 232-8, p. 39-85.
Levson, V., 1992, The Sedimentology of Pleistocene deposits associated with placer- gold bearing gravels in the Livingstone Creek Area, Yukon Territory. In: Yukon Geology Volume 3, Exploration and Geological Services Division, Northern Affain Program, Indian and Northern Affairs Canada, p. 99- 132.
Levson, V. and Morison, S.R., 1995. Geology of placer deposits in glaciated environments. In: Glacial environments-processes, sediments and landforms. J. Menzies (ed.), Pennagon Press, Oxford, U.K.,p. 44 1-478.
Matthews, J.V., Jr., Schweger, C.E. and Hughes, O.L., 1990. Plant and insect fossils from the Mayo Indian Village section (central Yukon): new data on the middle Wisconsinan environments and glaciation. Geographie Physique et Quatemaire, v. 44, p. 15-26.
McConnelf, ROCo,190 1. Exploration of Tintina Valley from the Klondike to Stewart River. Sum. Rep. for 1900. In: Yukon Territory, Selected Field Reports of the Geological Survey of Canada 1898 to 1933, H.S. Bostock (ed.), Geological Survey of Canada, Memoir 284, p.26-29. McTaggart, K.C., 1960. The Geology of Keno and Galena Hills, Yukon Territory. Geological Survey of Canada, Bulletin 58.
McTaggart, K.C. and Knight, J., 1993. Geochemistry of Lode and Placer Gold of the Cariboo District, B.C.. Province of British Columbia Ministry of Energy, Mines and Petroleum Resources, Mineral Resources Division, Open File 1993-30,24 pp.
Miall, A.D., 1982. Analysis of fluvial depositional systems. American Association of Petroleum Geologists, Education Course Note Series #20, University of Toronto, 75 PP-
Miall, A.D., 1992. Alluvial Deposits. In: Facies Models, response to sea level change. R.G. Walker and N.P. James (eds.), Geological Association of Canada, p. 1 19- 142.
Monger, J.W.H., 1989. Overview of Cordilleran Geology. Chapter 2: In: Western Canadian Sedimentary Basin, B.D.Ricketts (ed.), Canadian Society of Petroleum Geologists.
Monger, J.W.H., Price, R.A. and Templeman-Kluit, D.J., 1982. Tectonic accretion and the origin of the two major metamorphic and plutonic welts in the Canadian Cordillera. Geology, v. 10, p. 70-75.
Morison, S.R., 1983. Placer deposits of Clear Creek drainage basin, 1 1SP, central Yukon. In: Yukon Exploration and Geology 1983, Exploration and Geological Services Division, Northern Affairs Program, Yukon Region, p. 88-93.
Morison, S.R., 1985. Sedimentology of the White Channel placer deposits, Klondike area, west central Yukon. Unpublished MSc. Thesis, University of Alberta, Edmonton, Alberta, 149 pp.
Morison, S.R., and Hein, F.J., 1987. Sedimentology of the White Channel Gravels, Klondike Area, Yukon Territory: Fluvial deposits of a confined valley. In: Recent Developments in Fluvial Sedirnentology, F.G. Ethridge, R.M. Flores and M.D. Harvey (eds.), Volume Special Publication 39, Society of Economic Paleontologists and Mineralogists, p. 205-2 16.
Oswald, E.T. and Senyk, J.P., 1977. Ecoregions of Yukon Territory. Canadian Forest Service, Fisheries and Environment Canada. 115p.
Reading, H.G., 1986. Sedimentary environments and facies, zndedition. Blackwell Scientific Publications, Oxford, 6 15 pp. Rust, B.R., and Koster, E.H., 1984. Coarse Alluvial Deposits. In: Facies Models, Second Edition, R.G. Walker (ed.), Geoscience Canada Reprint Series 1, p. 53-69.
Ryder, J.M., 197 1. The Stratigraphy and Morphology of Para-glacial Alluvial Fans in South-central British Columbia. Canadian Journal of Earth Sciences, v. 8, p. 279- 298.
Smit, H., Sieb, M. and Swanson, C., 1995. Summary Information on the Dublin Gulch Project, Yukon Territory. In: Yukon Exploration and Geology 1995, Exploration and Geological Services Division, Northern Affairs Program, Yukon Region, p. 33-36.
Stevens, R.D., Delabio, R.N. and Lachance, G.R., 198 1. Age determinations and geological studies: K- Ar isotopic ages, Report 1 5. Geological Survey of Canada, Paper 8 1-2.
Stevens, R.D., Delabio, R.N. and Lachance, G.R., i987. Age determinations and eeoiogical studies: K-Ar isotopic ages, Report 16. Geological Survey of Canada, b Paper 82-2.
Tarnocai, C., Smith, C.A.S. and Hughes, O.L., 1985. Soil development on Quaternary deposits of various ages in central Yukon Territory. In: Current Research, Part A. Geological Survey of Canada Paper 85- 1 A. p. 229-238.
Templeman-Kluit, D.J., 1979a. Five occurrences of transported synorogenic clastic rocks in Yukon Territory. 61: Current Research, Geological Survey of Canada, Paper 79-IA, p. 1-1 1.
Templeman-Kluit, D.J., 1979b. Transported cataclasite, ophiolite and granodiorite in Yukon: evidence of arc-cont inent collision. Geological Survey of Canada Paper 79- 14.
Templeman-Kluit, D.J., 1980. Evolution of Physiography and Drainage in Southern Yukon. Canadian Journal of Earth Sciences. v. 17, p. I 189-1203.
Templeman-Kluit, D.J., 198 1. Geology and Mineral Deposits of Southern Yukon. In: MAC ( 198 1), Yukon Geology and Exploration 1979- 1980; Exploration and Geological Services Division, Indian and Northern Affairs Canada, p. 7-3 1.
Tuck, R, 1968. Origin of the bedrock values of placer deposits. Economic Geology, v. 63, p. 191-193.
Vernon, P. and Hughes, O.L., 1966. Surfcial geology, Dawson, Larsen Creek and Nash Creek map areas, Yukon Territory (1 16B and 1 16C east half, 1 16A and 106D). Geological Survey of Canada, Bulletin 136,25 pp. Walker, R.G, 1984. General Introduction: Facies, Facies Sequences and Facies Models. In: Facies Models, Second Edition, R.G. Walker (ed.), Geoscience Canada, Reprint Series 1, p. 1-9.
Walker, R.G., 1992. Facies, facies models and modem stratigraphic concepts. In: Facies Models, Response to Sea Level Change, R.G.Walker and N.P. James (eds.), Geological Association of Canada, p. 1- 14.
Wheeler, J.O. and McFeely, P., 199 1. Tectonic assemblage map of the Canadian Cordillera and adjacent parts of the United States of America. Geological Survey of Canada, Map 17 12, 1 :t 000 000 scale.
Yukon Minfile. Exploration and Geological Services Division, Yukon, Indian and Northern Affairs Canada, Whitehorse, Yukon. APPENDIX A
GRAIN SIZE ANALASYS - DATA AND RESULTS
APPENDIX B
FABRIC DATA AND CLAST LITHOLOGIES Fabric -Unit #3 LW-97-02 June 26/97 Number L~thology Imbncatlon Stnke 1 vein qtz a IS1
qtzte schist qme schist schist qme vein qtz
schist qtae schist
qme granodiorite schist schist schist ganodiorite granodiori te schist schist schist granodiorite
we schist
schist schist schist
podiorite
qme we schist schist
granodiorite schisty qtzte schisty qtzte granodiorite schist
qtzte Fabric -Unit #3 LW-97-02continued, Strike JLZ7. 52 schist 260 53 schist 163 54 diorite 296 55 qtae 30 56 qtzte 210 57 qtzte 4 58 qtzte 256 59 schist 171 60 schist 339 61 qtzte 200 62 schist 249 63 qtzte 1 74 64 qtae 175 65 schist 25 1 66 vein qtz 180 67 granodiorite 185 68 schist 130 69 schist 192 70 granodiorite 249 71 qtae 285 72 qtzte 205 73 schist 216 74 qtae 217 75 qtzte 334 76 qtzte w. veins 34 1 77 qtae 230 78 qtzte 175 79 schist 309 80 diorite 16 81 schisty 14 82 qtzte 280 83 qtzte 244 84 qtae w. veins 235 85 schist 192 86 qtzte 273 87 qtae 92 85 granodiorite 105 89 granodiorite 198 90 schist 193 91 schist 108 92 schist 207 93 schist 322 94 schist 277 95 granodiorite 327 96 qtae 89 97 qtzte 272 98 schist 285 99 qtzte 259 100 granodiorite 203 Fabric-Unit #I LW-97-04 Julv 1/97 Fabric-Unit #I LW-97-04 co~ Litho togy
grey qtzte lve qtzte /schist schisty qtzte schisty qtzte schisty qtzte qtzte schisty qtzte qtzte schisty qtzte
qtzte
qtzte qtzte
schisty qtzte qtzte w. pyrite vein qtzte qtzte qw= qwe qtzte Fabric - Unit #3 LW-97-04 June 27/97 Number L~tholo~gy rm bncat~on Strike D 1~ ' 1 schlst b 263 21 2 qtzte b 223 34 3 qtzte b 5 9 4 scbisty qtzte b 321 16 5 qtzte b 30 16 6 qtzte b 304 30 7 granodiorite b 3 10 48 8 granodiorite b 32 1 52 9 granodiorite b 302 62 10 qtzte b 338 40 11 qtzte b 342 54 12 qtzte w. veins b 3 14 IS 13 qtzte w. veins a 225 19 14 diorite b 2 10 42 15 qtzte b 301 20 16 qtzte b 38 3 1 17 qtzte b 311 66 18 qtae a 238 49 19 schist a 50 43 20 qtzte b 226 44 2 1 qtzte b 149 33 22 qtzte b 228 35 23 vein qtz b 222 66 24 diorite b 4 42 25 qtae b 296 21 26 qtzte a 20 1 31 27 qtzte w. veins b 296 26 25 granodiorite b 324 4 29 granodiorite b 330 36 30 qtzte w. veins b 3 15 34 3 1 Oofanodiorite a 257 62 32 schist b 300 74 33 granodiorite b 226 67 34 granodiorite a 257 53 35 granodiorite b 335 51 36 qtzte a 52 28 37 schist a 337 19 38 qtzte a 109 34 39 qtzte a 195 47 40 vein qtz a 60 3 41 qtzte b 242 73 42 granodiorite b 329 76 43 diorite b 1 34 44 schistyqtzte a 28 1 16 45 schisty qtzte b 300 63 46 qtzte b 154 3 1 47 diorite a 230 45 48 schisty qtzte b 233 34 49 granodiorite a 260 54 50 schist b 225 28 Fabric - Unit #3 LW-91-04continued. Nurn ber Lithology Stnke 3 I ve~nqtz 233 schist- 225 qtae w. veins 265 qtzte 223 'It= 26 1 'Itzte 191 schisty qtzte 130 'Ime 227 qtzte 136 vein qtz 270 9tzte 334 granodiorite 296 schisty qtzte 325 granodiori te 302 301 qme 35 qtae w. veins 246 diorite 238 schisty qtzte 2 15 qtzte w. veins 320 qme 234 qtae 282 qme 328 clme 264 qme 268 268 286 qtae 197 310 diorite 196 236 diode 3 19 292 qm= 28 1 diorite 205 313 schisty qtzte 340 19 vein qtz 23 335 qwe 333 145 qme 144 336 diori te 316 qtae 245 qme 2 14 schist 247 9fzfe 339 qtzte w. hematite 345 Fabric-Unit #6 LW-97-05 July 3/97 Pumber Lithology lmbncation Stnke DIP I 1 sch~styqtzte a 26s 43 2 graphitic schist a 252 34 3 qtzte b 240 17 4 schisty qtzte b 200 38 5 qtzte a 11 18 6 qtzte b 33 1 54 7 granodiorite a 229 33 8 qtzte b 290 25 9 qtzte b 26 1 30 10 graphitic schist b 244 35 I I qtzte w. veins b 252 90 12 qtzte w. veins b 285 37 13 graphitic schist b 326 I I 14 graphitic schist b 266 12 15 qtzte b 322 22 16 qtzte b 70 58 17 vein qtz b 262 60 18 vein qtz b 86 9 19 qtzte b 330 49 20 gabbro b 294 29 2 1 qtzte b 284 35 22 fe-st. qtzte b 268 22 23 vein qtz b 269 30 24 qtzte w. veins b 235 53 25 graphitic schist ;1 334 22 26 fe-st. schisty qtzte a 274 25 27 graphitic schist b 312 25 25 fe-st. qtzte b 265 21 29 schist b 14 3 1 30 qtzte b 345 46 3 1 schisty qtzte a 230 19 32 schisty qtzte b 75 46 33 qtzte a 185 68 34 schisty qtzte a 155 6 35 fe-st. qtzte b 285 29 36 schisty qtzte a 255 21 37 schisty qtzte a 98 46 38 qtzte a 336 35 39 schist a 202 30 40 grey qtzte w. veins a 200 26 41 grey qtzte a 229 25 42 schisty qtzte a 346 49 43 schisty qtzte a 24 47 44 graphitic schist b 332 32 45 grey qtzte w. veins a 260 20 46 schisty qtzte b 24 1 42 47 vein qtz b 250 21 48 schisty qtzte a 265 8 49 schisty qtzte a 250 24 50 qtzte a 304 44 Fabric-Unit #6 LW-97-03continued. Number LrthoIogy Imbncatlon S tn ke 31 qtzte b 2x2 vein qtz vein qtz vein qtz vein qtz granodiorite fe-st. qtzte qtae qme qme vein qtz qtzte fe-st. qtzt
qne vein qtz qtzte qtzte qtzt= grey qtzte w, veins fe-st. qtzte fe-st. qtzte granodiori te grey qtzte w. veins grey grey qtzte w. veins qtzte granodiorite (fe-st .) vein qtz qtzte gabbro agmodiorite grey qtzte schisty qtzte fe-st. schisty qtne schisty qtzte vein qtz schisty qtzte schisty qtzte SeY graphitic schist schisty qtzte grey qtzte vein qtz grey qtzte w. veins fe-st. qtzte schist -modiori te vein qtz Fabric-Unit #3 LW-97-02b July 12/97 Number Lithology .mbncation KOUndneSS Length a-axis ( 1 te-st. qme a schlsty- - sa Icm schisty qtzte b schist b b schisty qtzte b qtzte b schist a *gaphitic schist b graphitic schist b qtzte a schist a schist b b fe-st. qtzte b schist b qtzte b schist a qtzte a schist a qtzte b graphitic schist a schist b schist b graphitic schist b fe-st. qtzte a schisty qtzte a schisty qtzte b diorite a schisty qtzte a schist a schisty qtzte a schisty qtzte a qtzte b schisty qtzte a qtzte a diori te a schisty qtzte b schisty qtzte b schisty qtzte b graphitic schist b schist a schist b qtzte a qtzte a schist a schisty qtzte b diorite b schisty qtzte b schisty qtzte b schist^ atzte b Fabric-Unit #3 LW-97-05 July 4/97 Number I Lithology Koundness 1 Length a-aulscrn 7 sa L. schisty qtzte sa Ischist sr v. qtz ST lqme sr I&aphitic schist sr grey qtzte w. veins sr graphitic schist sa
c.mphitic schist sa sr mphitic schist sr schisty qtzte sr qtzte sr qme sr v. qtz sa graphitic schist sa graphitic schist sr ganodiorite sr graphitic schist sa sr IgY;qtae w. veins sr qtzte r lwe sa schist w. garnet sr mey qtzte w. veins C sa q*= Sf schist sa diorite sr =gaphitic schist Sf sa r a a lvein qtz sa sa Ischisty qtzte a 1 schisty qtzte sr qtde sa schisty qtzte sr fe-st. qtzte sr lgraphitic schist a schist Sf qtzte sa diorite ST [schistyqtzte sa 1schisty qtzte sa schisty qtzte sa fe-st. schisty qtzte sr schisty qtzte a Sf Fabric - Unit #6 LIV-97-08 July 25/97 Number Lithology lmbncat~on Stnke D~P Roundness Length a-axls Isch~st a -3 14 a L Y 2 qtzte b 36 25 3 qtzte b 64 24 4 schist a 65 35 5 schist b 62 3 1 6 qtzte b 121 30 7 graphitic shist b 82 40 8 a 55 12 9 a 107 25 10 schisty qtzte a 119 10 I I qtzte a 76 35 Fabric - Unit # 1 LW-97-09 August 9/97 Number L~tholo~gy Stnke DIP Koundnessl Lenah a-axis icm I qtzte 33 2 schist 199 43 3 Ischist 195 30 4 Ischisty qtzte 136 26 5 1 schisty qtzte 205 32 208 39 I 182 30 schisty qtzte 1SO 30 198 25 schist 203 18 vein qtz 183 18 qme 220 19 165 26 fe-st. qtzte 235 15 15 schisG qtzte 227 16 16 fe-st. qtzte 24 1 34 I7 qtzte 22 1 28 schisty qtzte 216 26 fe-st. qtzte 189 26 fe-st. qtzte 208 19 fe-st. qtzte 205 39 qtz. augen schist 222 39 l?eY qtzte 181 38 fe-st. qtzte 178 22 fe-st. qtne 22 1 23 295 46 we 277 26 schisty qtzte 273 35 schisty qtzte 204 46 qtzte 212 1 fe-st. qrte 269 29 32 grey qtzte w. veins 205 43 33 grey qtzte 316 20 34 qtzte 270 49 grey qtzte w. veins 240 30 schisty qtzte 255 27 ,prey qme 205 44 fe-st. qtzte 208 20 qme 110 17 170 32 4 1 qtz. aug& schist 292 2 1 42 qtz. augen schist 23 1 34 43 schisty qtzte 254 34 232 40 45 schisty qtzte 155 25 46 grey qtzte 339 16 47 vein qtz 340 18 49 lschirty qtzte 22817' 1 i 50 -eyatzte w. veins 211 Fabric - Unit # 1 LW-97-10 Number L i tho Iogy lmbncatlon Stnke Ulp Koundness Length a-auls (cm j0 I schisty qtzte b L92 -70 sa 9.3 2 qtae b 239 20 sa 10 3 grey qtzte b 92 77 sr 8 4 schist a 312 33 sr 5 5 schisty qtzte b 134 19 sa IS 6 vein qtz a 168 2 1 sa 9 7 schisty qtzte a 288 2 1 sa 9 8 qtzte a 329 29 sa 6.5 9 schisty qtzte a 220 3 1 sa 5.5 10 grey qtzte b 356 32 sr 8 1 I schisty qtzte 3 52 30 sa 20 12 tie-st. qtzte b 25 32 sa 12 13 schisty qtzte b 330 49 sa 10 14 schisty qtzte a 109 32 sa 12 15 schisty qtzte a 0 16 sa 6 16 schisty qtzte b 127 36 sa 6 17 qtzte a 162 20 sa 7 18 schist b 138 27 sr 9.5 19 schisty qtzte a 155 44 sa 9.5 20 schist b 284 37 sr 8.5 21 qtzte a 297 29 sa 23 22 qtzte a 297 60 sa 10 23 a 50 24 24 schisty qtzte b 320 40 ST 8 25 grey qtzte a 41 3 1 sr 6.5 26 schisty qtae a 145 39 sr 13 27 schist b 6 1 52 sa 10 25 =gaphitic schist b 229 16 ST 9.5 29 =gaphitic schist a 310 72 ST 9.5 30 schisty qtzte a 139 53 sa 9 3 1 qtzte a 157 21 sr I I 32 schist a 130 22 sa 10.5 33 schisty qtzte b 1 64 3 1 sr 7.5 34 qtzte b 259 43 sr 8.5 35 qtzte a 80 36 ST 7.5 36 qtzte b 309 21 sr 13.5 37 qtzte b 262 27 sa 9.5 35 qtzte b 110 58 ST 7 39 schisty qtzte a 210 16 sr 12 40 qtzte b 292 20 sr 16 41 schist b 142 12 sr 10 42 qtzte b 62 5 sa 11 43 qtzte b 142 19 sa 12 44 schisty qtzte b 27 1 15 sa 9 45 schisty qtzte b 252 23 sa 8 46 schisty qtzte b 10 30 sr 14 47 qtzte b 300 17 sr 14 45 schist a 2 15 2 sr 9 49 qtzte b 35 1 30 sa I4 50 schisty qtzte b 103 52 sa 12 Fabric - LW-97-12' August- 14/97 ' &umber LlhoIo~ Imbncatron Stnke Ulp Roundness Lengh a-axts (cm) I PeY qtzte b -74 1 -34 r 20 2 qtae b 246 40 sr 9.5 3 schisty qtzte b 34 I 19 sa 8 4 schisty qtzte b 300 50 sa 11 5 qtae a 2 25 sa 9 6 qtzte a 502 41 sr 6.5 7 qtae b 250 3 1 sr 14.5 8 fe-st. qtzte b 245 36 sr 6 9 schisty qtzte a 250 48 sr 10 10 graphitic schist a 290 24 sr 9.5 11 qtzte a 115 64 ST 8.5 12 qtae a 330 36 sr 9.5 13 fe-st. qtzte b 358 11 sa 10 14 graphitic schist b 5 1 20 sr 7 15 graphitic schist b 311 30 sr 11 16 qtzte b 328 19 ST 10 17 qtae a 258 48 sr 13 18 graphitic schist a 280 28 sr 9 19 schisty qtzte a 23 1 36 ST 6.5 20 schisty qtzte b 65 25 sr 19 2 1 schisty qtzte b 330 1 I sr 12 22 schisty qtzte a 302 27 sr 10 23 qtae a 280 88 sr 8.5 24 fe-st. schisty qtae a 262 5 1 sr I5 25 schisty qtzte b 304 52 r 7 26 schisty qtzte b 243 39 st 9 27 fe-st. qtzte a 270 32 sa 10 28 fe-st. qtzte a 255 33 sa 6 29 fe-st. qtzte a 265 27 sa 9 30 fe-st-qtzte a 260 37 sf 6 3 1 grey qtzte w. veins b 260 47 sr 8 32 schist a 255 34 sr 5.5 33 fe-st. qtzte b 242 40 sa 9.5 34 grey qtae a 288 32 sa 7.5 35 qtae b 288 3 1 sa 9 36 schist a 300 48 sa 1 I 37 qtzte a 282 34 sa 6 38 vein qtz a 272 38 sf 8 39 fe-st. qtzte b 288 44 sr 15 40 grey qtzte b 250 30 sr 12 41 schist a 271 47 sr 5 .S 42 fe-st. qtzte a 270 46 sa 5 43 fe-st. qtzte b 267 40 sa 7 4 grey qtzte ' a 260 30 ST 15 45 fe-st. qtzte a 277 3 1 sr 13 46 schist b 27 1 26 sr 10 47 fe-st. qtzte a 290 33 sr 14 45 qtzte b 287 32 sr 12 49 geyqtae a 258 20 sf 22 50 fe-st. qtzte b 260 15 sr 16 Fabric - Unit #1 Gill 4 August 15/97 Number ( L1thoIo.w i ischisty qtzte fe-st. qtzte fe-st. qtzte fe-st. qtzte &gaphiticschist fe-st. qtzte schisty qtzte fe-st. qtzte schisty qtzte Fe-st. qtzte vein qtz fe-st. qtzte schisty qtzte fe-st. qtzte Ife-st. qtzte fe-st. qtzte fe-st. qtzte fe-st. qtzte schisty qtzte fe-st. qtzte schisty qtzte schisty qtzte fe-st. qtzte vein qtz schisty qtae
schisty qme qme schisty qtzte qtzte qtzte w. veins schisty qtae vein qtz schist
qtzte w. veins qtde schisty qtzte schist schist
schist schisty qtzte schisty qtzte schist vein qtz qtzte schisty qtzte qtzte Fabric - Unit #I LtV-97-14 Number ' L~tholo~q 1 te-st. qtzte schisty qtzt vein qtz fe-st. qtzte fe-st. qtzte fe-st. schisty qtae fe-st. schisty qtzte fe-st. qtzte fe-st. qtzte fe-st. qtzte fe-st. schisty qtae schisty qtzt fe-st. qtzte fe-st. qtzte schist qtzte schist grey qtae fe-st. qtzte qtzte fe-st. schisty qtzte vein qtz fe-st. qtzte fe-st. qtzte fe-st. qtzte fe-st. qtzte vein qtz fe-st. qtzte qtzte w veins schisty qtzt fe-st. qtzte fe-st. qtzte fe-st. qtzte fe-st. qtzte schist schist fe-st. schisty qtae fe-st. schisty qtzte fe-st. schisty qtne fe-st. qtzte fe-st. qtzte fe-st. schisty qtzte qtzte schisty qtzte schist fe-st. qtzte schisty qtzte fe-st. schisty qtzte erev atzte w. veins Fabric -Unit #I Gill 3 August 19/97 Number LlthologY Imbncation Stnke Ulp Roundness Length a-axis (cm) , I qtzte b 8 1 9 a 6 2 schist b 292 62 a 10 3 schisty qtzte a 157 14 a 8 4 schisty qtzte b 350 61 a 13 5 schist b 20 1 56 a 9 6 schisty qtzte b 295 15 sa 8 7 schisty qtzte b 171 I6 sr 13 8 schist b 10 43 ST 9 9 qtzte b I I2 76 sa 6 10 schisty qtzte b 159 37 sa I I 1 I fe-st. schisty qtne b 354 52 sa 7 12 qtzte b 225 47 sa 6.5 13 qtzte w. veins b 292 17 sa 9 14 fe-st. schisty qtzte a 28 1 43 a 9 15 qtae a 193 8 sa 8.5 16 schist a 215 19 a 11 I7 grey qtzte a 267 10 sa I1 18 qtzte b 333 13 a 9 19 fe-st. schisty qtzte b 253 26 sa 11.5 20 fe-st. schisty qtzte a 326 37 a 5 2 1 schisty qtzte a 229 19 a 7 22 schisty qtzte a 324 IS a 5 23 schisty qtne b 38 24 sa 7 24 qtzte a 40 8 a 13 25 schist a 5 48 a 5.5 26 fe-st. diorite a 160 15 sa 10 27 qtzte b 270 25 sa 9 28 grey qtizte w. veins a 60 26 sa 7 29 fe-st. diorite b 275 38 sa 3 30 schist b 312 29 a 5 3 1 schist b 345 26 a 6 31 fe-st. qtzte a 155 29 a 3 -5 33 schisty qtzte a 300 20 a 5.5 34 schist a 275 14 a 4 35 schisty qtzte b 292 25 a 7 36 fe-st. qtzte a 277 17 sa 7 37 schisty qtzte a 27 1 I I a 8.5 38 schisty qtzte a 300 20 a 10 39 schisty qtzte a 262 27 a 8 40 schist a 290 26 a 5 4 I schisty qtzte a I29 34 a 4 42 schist a 122 22 a 5 43 schisty qtzte a 325 22 sa 4.5 44 qtzte b 319 17 a 3.5 45 fe-st. qtzte a 110 21 sa 4 46 schist b 319 16 sa 5 47 schisty qtzte b 270 36 a 4.5 48 fe-st. qtzte b 275 15 a 10 49 fe-st. schisty qtae b 255 36 sr 7 SO vein qtz a 292 22 a 4 Fabric - Unit #J LW-97-15 August 19/97 Fabric - Unit #1 LW-97-16 Number LItholo,gy 1 fe-st. dionte 2 fe-st. qtzte 3 fe-st. qtzte 4 fe-st. schist 5 fe-st. qtzte 6 fe-st.qtzte 7 fe-st. schisty qtzte 8 schist fe-st. schisty qtzte fe-st qtzte fe-st. qtzte fe-st. schisty qtde fe-st. qtzte fe-st. qtzte fe-st. qtzte fe-st. schisty qtae fe-st. qtzte fe-st. schisty qtzte fe-st. qtzte fe-st. qtzte fe-st. schisty qtzte fe-st. qtzte fe-st. qtzte fe-st. qtzte fe-st. schisty qtzte fe-st. schisty qtzte fe-st. schist fe-st. schist
fe-st. schisty qtzte grey schist fe-st. schisty qtzte fe-st. qtzte fe-st qtzte fe-st. qtzte w. veins fe-st. qtzte fe-st. qtzte schisty qtzte fe- & rnn-st. qtzte fe- & rnn-st. qtzte fe- & mn-st. qtzte schisty qtzte 44 Ischisty qtzte 45 fe-st. qtzte fe-st. qtzte fe-st. schist fe-st. schist oraphitic schist ? te-st. atzte Fabric - Unit #2 LWr-97-17 / Length a-axw 'schist fe-st. schisty qtzte fe-st. qtzte schist fe-st. schisty qtzte fe-st. qtzte schisty qtzte schist
fe-st. qtzte fe-st. schisty qtzte schist fe-st. qtzte schist fe-st. grey qtzte fe-st. qtzte fe-st. grey qtzte fe-st. qtzte fe-st. schist sey qtzte qtzte schist grey qtzte grey qtzt= schist qtzte
fe-a. schisty qtae schisty qtzte fe-st. qtzte
schist schist fe-st. schisty qtne
PYwe fe-st. qtzte qme qtzte schist fe-st. qtzte schisty qtzte grey qtzte schist schisty qtzte WY schisty qtzte Fabric - Unit #1 LW-97-20 Number L~thology 1 te-st. qtzte granodiorite fe-st. qtzte ,pnodiorite schist aganodiorite fe-st. qtzte schist fe-st. qtzte fe-st. schisty qtae fe-st. qtzte fe-st. qtzte fe-st. schist schist fe-st. qtzte fe-st. qtzte fe-st. schisty qtzte fe-st. schisty qtzte Dgranodiorite granodiorite fe-st. qtzte fe-st. qtzte fe-st. qtzte fe-st. qtzte fe-st. schisty qtzte fe-st. qtzte fe-st. schist fe-st. qtzte schisty qtzte schisty qtzte graphitic schist sc histy qtzte fe-st. qtzte granodiorite schist grey qtzte fe-st. schisty qtae qtzte
granodiorite schist schist graphitic schist fe-st. schisty qtae granodiorite =-phitic schist schisty qtzte schisty qtzte schist granodiori te Fabric - Unit #1 LW-97-2 1 August- 28/97 Number Lithology lmbncatron Stnke Ulp Roundness Length a-axis (cm
I ,oranodronte a 80 40 sr C73 2 vein qtz a 79 20 a 13 3 grey qtzte b 101 47 sa 12 4 schisty qtzte b 105 50 sa 14.5 5 granodiorite a 82 22 sr boulder 6 ,modiorite a L 02 25 sr boulder 7 fe-st. schist a 70 45 sa 6 8 fe-st. schisty qtzte a 54 46 sa 11.5 9 granodiorite b 54 48 sr 25 10 fe-st. vein qtz b 330 22 sa cobble 1 1 fe-st. qtzte a 42 3 1 sa I1 12 granodiorite a I10 15 ST boulder I3 gmnodiorite b 112 21 sr cobble to bouIder 14 granodiorite a 128 39 ST I3 15 schisty qtzte a 110 37 sa 8 16 fe-st. qtzte a 110 42 a 12 17 fe-st. grey qrzte b 58 33 sa 11 I8 fe-st. qtzte a 250 I8 a 14 19 podiorite b 130 71 sa 9 20 granodiorite b I08 24 ST bouIder 2 1 schisty qtzte a 5 1 22 a 7 22 ganodiorite a 80 16 sr 17 23 qtzte b 6 1 8 sa boulder 24 +ranodiorite a I50 34 ST 8 25 fe-st. schisty qtzte a 74 50 sr 10 26 graphitic schist b 328 38 a 11 27 fe-st. vein qtz b 100 47 sr 8 28 fe-st. schisty qtzte b 142 7 1 sa 8 29 tmodiorite a 15 1 57 sr 18 30 granodiorite a 154 32 sa 23 3 1 fe-st. qtzte b 71 48 sa 9.5 32 fe-st. qtzte a 105 30 sa 7 33 fe-st. qtzte a 85 27 sa 7.5 34 fe-st. qtzte a 196 90 sa 5.5 35 pnodiotite b 132 48 ST 18 36 eganodiorite b 100 43 sr 22 37 &granodiorite a 23 14 ST 11 38 schisty qtzte a 30 27 sr 11 39 fe-st. schisty qtae b 324 15 a 10.5 40 fe-st. schisty qtzte b 139 7 sa 7 4 1 schisty qtzte b 342 79 a 9 42 bpnodiorite b I04 5 1 ST 13 43 schisty qtzte a 84 43 sr 11.5 43 schisty qtae a 160 73 a 5 45 fe-st. qtzte a 22 90 sr 6 46 Cpnodiorite a 92 47 sr >16 47 qtzte b 97 36 sa 5 45 -gaphitic schist b 346 74 a 5 49 fe-st. schisty qtzte a 266 23 sr 10 50 fe-st. qtzte b 305 82 sr 7 Fabric - Unit- - #2 LW-97-2 1 August- 28/98 Number Lrtholo-q lrnbncat~on Stnke L)lp Roundness Length a-a.us (cm)- 7. Isch~sty qtzte a 320 7 I ST 8 -7 schist b 30 1 22 a 4 3 qtzte b 30 1 29 a 3.5 4 schisty qtzte a 343 12 sa 8 5 schist b 45 33 ST 4 6 fe-st. qtzte a 11 15 a 5 7 fe-st. qtzte a 325 18 sa 6 8 schist b 10 20 sa 3.5 9 fe-st. schisty qtzte a 283 15 sa 4 10 fe-st. qtzte a 352 15 ST 3 11 schisty qtzte a 2 18 sa 4.5 12 fe-st. schisty qtzte a 282 30 ST 3.5 13 schist a 340 18 a 3.5 14 fe-st. qtzte b 310 40 sa 6 15 fe-st. qtzte b 5 54 a 8 16 fe-st. qtzte a 340 74 a 7 17 granodiori te a 297 I8 a 8 18 fe-st. schisty qtae a 18 23 sa 9 19 =p.nodiorite a 20 49 sa 6.5 20 granodiorite a 18 23 ST 7 2 1 fe-st. qtzte b 35 1 43 sii 7 33 sc histy qtzte a I1 33 a 6 23 fe-st. qtzte a 330 21 a 8 24 graphitic schist a 345 23 a 9 25 fe-st. schisty qtzte b 335 34 sa 6.5 Fabric - Unit #I LW-97-22 Number L~tholo~g I 1 te-st. qme fe-st. qtzte schist schist fe-st. schisty qtzte fe-st. schist fe-st. schist fe-st. qtzte fe-st. qtzte fe-st. schisty qtzte fe-st. qtzte lgraphitic schist fe-st. vein qtz Ife-st. schisty qtae Ife-st. schist 1 fe-st. schisty qtzte fe-st. schisty qtzte fe-st. schist Ife-st. qtzte Ischist grey qtzte fe-st, schist fe-st. grey qtzte fe-st. qtzte I fe-st. qtzte fe-st. qtzte fe-st. schisty qtzte Ife-st. schisty qtzte I=gaphitic schist grey qtzte qtzte schisty qtzte fe-st. schisty qtae fe-st. schisty qtae schisty qtzte fe-st. schisty qtzte esrey 1 schist =gaphitic schist !Fey qtzte schist fe-st. qtzte _maphitic schist
schist fe-st. &my qtzte fe-st. schisty qtzte fe-st. schist 1 fe-st. schisty qtae Ife-st. schistv atzte Fabric - Unit #2 LW-97-22 September 4/97 N urn ber L~tholo~v Tm bncation 1rend Plunge Roundness * Length a-axls- (cm) 1 sch~styqtzte a 34 2 ST 10.3 2 fe-st. schist a 46 14 sa S 3 fe-st. schist a 50 I8 ST 7 4 graphitic schist a 33 32 sr 3 5 schist a 210 5 sa 4 6 schisty qtzte a 346 20 sr IS 7 fe-st. qtzte a 325 4 ST 8.5 8 bgraphitic schist a 187 1 ST 3.5 9 fe-st. vein qzt a 249 3 sf 3 10 fe-st. qtzte a 244 9 sa 5 -5 11 schist a -c7 - 34 sr 5.5 12 schist a 13 36 sr 4 13 fe-st. vein qtz a 349 25 sa 5 14 grey qtae w. veins a 270 18 sa I5 15 fe-st. schisty qtzte a 26 21 sr 7 16 grey qtzte w. veins a 10 26 r 19.5 17 fe-st. schisty qtzte a 7 1 23 ST 4 18 fe-st. qtzte a 349 29 sa 3.5 19 graphitic schist a 19 17 sr 11.5 20 schist w. qtz veins a 340 3 sa 9 2 1 fe-st. schisty qtae a I4 10 sa 23 22 fe-st. schisty qtzte a 355 3 sa 8.5 23 diorite a 340 35 sr 5.5 24 grey qtzte w. veins a 35 1 24 ST 9 25 schist a 358 19 ST 3 26 fe-st. qtzte a 35 3 a 6 27 fe-st. schisty qtae a 17 20 sr 8 IS fe-st. qtzte a 26 17 sa 6 29 schist a 75 58 sa 4.5 30 fe-st. schisty qtne a 6 5 sa 8 3 1 fe-st. qtzte a 44 b3 sa 9 32 qtz augen schist a 33 8 r 25 33 fe-st. qtzte a 125 8 sa 7 34 schist a 24 16 ST 4 35 fe-st. qtzte a 26 16 r 3 36 fe-st. qtzte a 120 55 r 6 37 fe-st. vein qtz a 4 16 sa 7 38 fe-st.qtzte a 0 32 sa 5 39 fe-st. qtzte a 255 4 ST 5 40 fe-st. qtzte a 330 17 sa 10 4 1 fe-st. schisty qtne a 22 15 sa 8 42 fe-st. qtzte a 25 9 ST 9.5 43 qtzte a 20 25 sa 4.5 44 grey qtae w. veins a 20 30 sr 14.5 45 fe-st. schist a 348 19 ST 6.5 46 schist a 15 37 sr 5 47 graphitic schist a I6 32 ST 4.5 45 grey qtae w. veins a 337 22 sa 7.5 49 fe-st. schist a 352 30 sr 7.5 50 greyqzte a 332 20 sr Fabric - Unit #I LW-97-23 September 4/97 I Number Litholocgy Irnbncatron Stnke- - L)lp Roundness Length a-axls (cm) 1 a 133 6 r 4 ::!i::, ::!i::, ,Ute a 152 7 r 6 fe-st. qtzte a I55 4 1 ST 7 schist b 115 23 sr 5.5 grey qtzte w. veins a 157 19 ST 6 fe-st. schisty qtzte b 110 44 sr 6.5 qtzte a 120 26 sa 5.5 qae a 147 11 r 7.5 qtzte a 141 16 r 10 vein qtz a 141 2 1 sa 4 fe-st. qtzte a 152 12 ST 4.5 schist b 3 1 42 ST 7 grey qtzte w. veins a 127 I I ST 4 sandstone a 210 12 r 4 qtzte a 350 35 sr 8.5 qtne a 306 20 sa 7 qtae b 246 11 ST 8.5 fe-st. qtzte b 235 11 sr 6 scbisty qtzte a 142 3 1 sa 4 fe-st. qtzte a 213 11 sa 7 schist a 215 --77 sr 4 schist a 166 20 sr 3 fe-st. schist a 225 I1 sr 3.5 schist a 151 4 1 sr 2.5 fe-st. schist b 196 19 sa 4 Fabric - Unit #2 LW-97-25 September 5/97 1 lmbncatlon Stnk
I (schist a C7 qttte a 210 qne a 270 schisty qtzte a 258 qtzte a 230 schisty qtzte a 268 ,erey qme a 295 schist b 266 schisty qtzte a 222 qtzte a 264 schist a 327 qtzte a 285 qtzte a 283 qtzte a 268 Fey a 277 schist a 280 schist a 255 qtzte b 275 vein qtz a 297 schist a 296 vein qtz a 302 qtzte a 288 schisty qtzte a 245 qtzt e a I 76 grey qtzte w. veins a 205 qtzte a 282 a 29 1 granodiorite a 286 SeY we a 285 vein qtz a 247 qtzte b 273 qtzte b 267 qtzte b 5 IS schist a 270 we a 285 schisty qtzte a 285 grey a 3 10 clme a 26 vein qtz a 343 a 27 I a 283 qtzte a I12 qtzte b 18 1 granodiorite a 294 qtzte b 242 schisty qtzte b 296 a 279 fe-st. qtzte a 273 qme b 225 schistv atzte a 238 Fabric - Unit #I LW-97-27 September 7/97 1 rend
173 144 59 250 223 160 162 22 1 178 296 205 193 Fabric - Unit #3 LW-97-27 Se~ternber7/97 L . I Number LIthoIobq Imbncatron' Stnke ' Dip I schlsty qtzte b I98 9 2 schist a 42 I0 3 schist a 40 14 4 qtzte a 295 22 5 schist b 273 35 6 schist a 32 I I 7 qtzte b 5 1 49 8 schisty qtzte a 306 4 9 schisty qtzte a 312 12 10 qtzte b 4 1 47 1 1 schisty qtzte a 232 25 12 fe- and mn-st. qtzte b 28 1 66 13 mn-st. schist a 33 1 3 1 14 fe-st. qtzte a 281 36 15 fe-st. schisty qtzte a 325 33 16 qtzte a 3 16 27 17 mn-st. schisty qtzte b 302 30 18 fe-st.qtzte a 205 20 19 schisty qtzte a 302 46 20 qtzte a 262 18 21 schist b 3 14 36 22 fe-st. schist a 235 28 23 qtzte a 205 20 24 -gaphitic schist a 233 24 25 fe-st. schisty qtzte a 72 25 26 fe-st. qtzte a 198 22 27 schisty qtzte a 35 1 5 1 25 fe-st. qtzte b 245 44 29 schisty qtzte a 257 16 30 qtae a 264 27 31 qtzte a 270 19 32 schisty qtzte b 276 59 33 schist a 274 35 34 schisty qtae a 232 19 35 schisty qtzte b 24 1 45 36 schisty qtzte b 247 35 37 qtzte b 24 I 13 38 schisty qtzte b 21 1 49 39 qtzte b 87 39 40 qtzte a 102 18 41 greyqtzte a 253 44 42 qtzte b 235 28 43 fe-st.qtzte a 253 21 44 schisty qtzte a 230 24 45 schist b 29 I 29 36 schisty qtzte b 256 5 1 47 schisty qtzte a 268 78 45 schist a 250 37 49 greyqtae b 290 28 50 qtzte a 26 1 28 APPENDIX C
MEASURED SECTIONS ------. ------. Datr2&@9J Salon number LW-97-Q1 Mclrud by: LW~~A Cmk or R~uer: H%e;lfl Creek ?iTS: 106M hlNdcMflf)*43"N Lmg11~&:~5~50'5j'w€levanon: 2450 mf:JS8535E709S525N Oncntx~an: 190' -- OIOa Gcomorph~cIa~diorm:Mcdid m Distal Braided StmmWandering Gmd Bcd~Cotlwhl~pmn ----- TiiEETrn ------_ ----
Grain Size
L 0 Id*.' g 35 --c -Q ------.A .-s3 . -me r. ,.Z$.d= > 5 Remarks -me - x? Sorting { 5 P~Jm 2 s2 .E.= B$~s,-.-t rppmw a " ant a -. -*- A -= - I ;I; 2 5 -* 4 G 7 h i $l!$;:?fJ~
Cwad interval: slumped debris.
--. - - - - :-- .: Sand Diamicton :- Cmss-smtified Tmughcms-stmtified -, Fossils - - . .. bfodificlrs: c = crude d = discontinuous
------_I_I__ __ ------_ - - -- - C ___ Dxe2~0_6~Sutlonnumk LW-97-04 Sl~udby: LWIT.4 Crak or kva: Hag~rtCmk hTS: 1 O6M LY1ruac:6.1_QO'J3"N Lonprud~!jS'SO'S3 "W Elevanon: 2450 l~Th1: ~58525E7098525~ Dlslmcm: I'M' -- - - 010' Gcomorphlc hndfom:bftdhI 10 [hstd Braided Strum/Wmdnhg Gmcl BcdiCollwiaI ~pm - - - - _ - - - =rn ------
tA U
La g Grain Size e d - Texture L. 2 -*b"ikb ti 3- -s VtU 3 - .- = "hk g V: .- C-E Remarks b. - --c - - 5 *s~;g5 Sorting 4 f -. g .Z 5 z .E L,< * - bppnw 2 -1 g 9 1 ea~-.~z *z A-- :: 8 5 < 3 3 4 R ftizjjb;silzz
- . . ,, . . 1s g . . - ... - Cdluvhrd orylics - Very plysand mut-sup- pondprbblc hicrwth isdared &la: 396 c[wr 65% mrr: clats m angular to A ~uhg~l~.weakly str;lrtficd in uppcrmw JO cm of unit. - Mb - rgr -114H - Tiiy woody dcbru ~;~ta+d n rhmughau unit, a well as C1 within organic-rich silt/finc sand lenur: bxt mow coneat- a;lrd a base of WII. Fc ud Mn mmgYrociscd A with pfty knscs: monled A thtwgh~unit.
------hl;ur~vtvery ti-F chy. - fins an moalcd with mall ek lenses dgnt: gritty ;~rc ~TD c=. H hln and Fc ltincd n- - - (epr
-. -- -. Fajcsa(=~r~rpmnL- &bk.cobbIc with ------bolYcdbarlh-- Legend __-I------_ - .a.- -- -. -- -. - - - * ,, Xfud (Siltlciy) Gnvel -. .. - - -- Planarstntifid 5- Massive Imbricate -- Ripples 5 Organics -- - -* ------.. -: Sand I- - -.a '- Dimicton -:. Cross-suatifid Tmugh cross-stratitid -- Fossils Modifiers: c = crude d = discontinuous ------.- - - Datclfi@v Secr!on number LW-97-06 Xfcuud by: LW/UI Cmk a HJgfPn Cmk NTS: 106~ tylrudcnv LanptudcJ 72* Grain Size Texture Remarks Covacd ~ntavd; slumped dcbns. Legend -- --- .------. ------T - - -- Mud (Silr/clay) Gnvel - Planar satified hiassive - Imbricate Ripples Organics ------Sand -. ,--", Diarnicton Cross-stratified -- Trough cross-stratilied Foss i 1s hldifim: c = crude d = discon~inuous -. ------.------. ------. -- -- - __ ___ ---I------__ . - Dart: 1 lt07/97 Secttan numk LW-97-06 Xlevurcd by: LW/ Liif Creek or kva: Hagp;ln Creek \TS: 106M h1tudcb~?)rf.19"~Longr~dr~C~<0'~~WEI~~tm: 2.180 UY: JSS525E7098Z5N Onmodon: 088' -- - - - 268. Gcomorph~chndfon:bfcdiai lo Discll Bnided StmnuW~ndeingGnvcl BcdColluvial Apmn - -. ------.- mn~.------__ _ . . ___ _ - . - - . -.- - . .. - - - -. - - - _ ------. u 4) UC m t Grain Size f -$ Texture L u ---hukLo 6 : Ln 3 --- .-5 5 u**2 .-U == L E pthk g 2 Remarks pule - Q 5 c0 .=u!g 5 E So~ing$ 2 A g .: 8 2,s r TI t - .ppmw 2 a( , 0 8 .s -z -, , , 8 = E4sstl; iI;i 2 C S < .n $ P :, 2 5 < 2 i;:ljiss~$.z3 - cI.rYtrc - >A chalcml m7 - d;;r -L* 2' w eho;drc - ? A riurolt w - L& && ha- Fc OrT -& -n&e bora - L, -- ------__- - ------. -- _ -_ I___-.___ . - -. - - -- !seeend ------. - - - . - . .- - . -_ - - - ::-- -- - :L :L Mud (SilVcIay) ;,c Gnvel --. Phmrsmtifid f., Massive - Irnhcate Ripplrs :, O~mics -. ------: :.: Sand ," . Dismicton Cross-stnti tied Trough cross-saritied Foss i Is .* - - h.fodifias: c = mde d = discontinuous .. - - -. ------..-. ------.. ------. - - - . - - . --- - . -- ...... _. _ ...... - Date:u,=1% Setion numk LW-97-06 Lfmurrd by: LW:L\f Cmk or Riva: Hag* CfC& STS: 106M L311tude6@f)O'.19'~ Lmgiru&:J;5*<~'5~"WElcvatim: ZJSO Ulht: J58525E7098ZSN ai m k =I Grain Size rd - E Texture L U -Z$ ; UI .--" 1 plWr " G .-b Remarks Lz -*I f = Sorting 4 z .- 2 .n 2 - Yppmw 6 '= cmr - Jg.5- t E 2 5 -.I*-St,, "s 3 ' 2 : - Intcrbdd (inter fin- nic-rich slit. silp-cloy ndfinc nn& with pcbblcsobble diinnict. Divnia is ma.-luppmcd ad marivc to m&ly smlfid (uvst2 m): clam YC nguh to subrmndrd and yt pedannatly pebbles with wp.10% cobbles in lower 2.5 m ofunit: ma. is predomi- nantly fmc sand lo grit. *anic-tich rdimm~sconnn of finc wnd ndsift to siIty/clay with kand srringcn of pnt: rnoda;ucty smifid: mat I waxly dcbns mnmd dmnaphout unit. Legend - L* - -- --a ------.<7: - -- :I Mud (Silt/clay) $.+ Gnvel -= Ptmarstntifid f- Mmive Imbricate - - Ripple & Og;mia -- -. :-.. Sand ;' ; Diamicron --- Cross-stntikd I_ Trough cross-stnti fird Fossils . - - - blodi fim: c = crude d = discontinuous ------. -- -- - . . - -- _ - .- - ___ D31e11&fw9J Sectton numk LW-97-09 hfcvud by: LW,L\I ~da Gill Gulch NTS: 106DJ ~~udcWl'41'w Longlrudc: I 15.5 I * KWElnar~on:2530 LII: 458200E7 1002794 Or~armton: 2 18. - 038 ~~~~~~ht~ladfi~~:Alluvial GnvcYAlluvial FmColluviw -- - ups------_- Grain Size Remarks - Sorting S vpmw hlodifim: c = crude d = discon~inuous . ....- ...... ___ __ -- ---_I--. _ _ -- - --___-_------_ __ _ . ------D;rre:1&0~7 Sectran number LIV-07- 12 btcuumi by: LW. LII Cmta ~va:Gill Gulch ns: 106W hrau&&m1*36"~ Longrtudc:yS. 5 1 ' IrWElcvanon: 2545 U~I:J58Z5E.7 100 125N Grain Size -5V) Remarks ------:....- Sand ,' : Diamicton -- . Cross-stnrified -- - Trough cross-stntifid .- Fossils Modifiers: c = mde d = discontinuous --- - . . - . .- -. - -. - - .------______------I)Jlt:Q,0&r Scctlon number: LW-97- 13 hlrvud by: LWtLkI C- or ~"a:Gill Gulch h'S: I 06 M l.jlaude6JloI 't7*vyLmgrtu&:U_toS1 '07-WETcvar~m: 2500 Ul'hl: 3583?5E.7 100050N Ol~enormn: 190' --- 010. Gcomorphlc landform: hbris now - - - upsucun------A __ _ _ ------_ Grain Size Remarks - ... .. -. a 4s ...... - ...... - -...... - ...... -425 . , - ...... - ...... - . - ...... 3.55- ... . , ,. . - ...... *. 3 iE ...... -.- ...... - . . -.. --A . . . . very Q-y Med.m.*poned psbuecwle uiimcl (ems Cha are anpular to wbrouraed. hPnWP Ws d larmnated ill and uay mad urrt Lacs 0- of wo~dydeem sac- 1- 1- thragWlt UlIC vrood =wal far C14 dslng a - .P*n*rom~QLkmedF~sta~nng~~~ Uht Chaa* structure. ------Legend ------.. ------__ ._ _-.-.- "------. .&"i; - -- -1 Plsti5- live Imbricate ~ippla .--- Mud (Silt/chy) A> Gnvrl -- -- -& oqmiEs ------A -- - A'L Dhrnicmn -- Cross-str;ldlTed -1-Trough cross-stnlified . . Foails ..-.- -. . Sand ... - - - Modifiers: c =crude d =disconlinuous . - - - - - . ------. -- -- .------Dote220897 Section number: LW-97-19 Masured by: LWILILI Cmk ot Rivcr. Dublin Gulch MS: I06M hdt11&6#!Y'08"~ Longicud~U5~~9';~"~Elm~don:2390 mb~:J59600E7101150N O"cnotjon: 052* -- 33' Gcomorphic bndform: Alluvial PliIUColluviill l\pn - P - _--..- --upsm -- - - - . -. -. - --_C____ pa -. . ------. ------I___._ VI U- VI 2 0'E Grain Size - Tanire - 6 & u .- : j Remarks 2 Sorting Z - 'ppmw G 'I. S 2 3 - P - , ...... - ...... -, ...... Mbdan a. Sea Unt II 11. 9 - 5 16m)Osm 5 3 --a-wl5 %&-!!an-Ncm#td Po* msd, mDc.*gpata pe4- ble dhmla mch lsdatsd cobole - ,sm3D10, s(~um);Cf~~~lrl~' ruban@% mblaanantrated atbasoduut Femgan re .U cmmfsd at base d UIIL . . ,ap* . - - [email protected] -pbc1.dmd#ML..aw -i-%a3 m -3- -1scm.4bahd~ OlrtWmM~hruWbut IkrmmocMmaabu. V-YW-.~. n . aa340m~rg-pr~blwtaimgmw,~1.m*. '--f*~phwd*#O~ ~~cc(dorp.rr~ndt~r~ -pn(rrdoatbkur: pbb)..mngtlrr:*rw.nf, I0.rd;Iklp.olof~d.m 9Oanram ocp-=;-mwtp.mamotaod --brCtrdang:nrbnY~. WD--D.O~~...L*- 10 ' - 1WP ' 5 5 Q YI~nml.tmq.rr)"-+ ma-%=-- ~-~c-&lam; &- Is marled bra to dmgsybram: mtrrr Fe-s~~ru.. a - n-- n o n tr o oA ~u~wI:~~~~. Maske Ine sandlost dy wnga Ihrouqnarr: dsamtlnucus plny-inw- 1OcJvl. Peaty wed. mh-suppated. Wbcot~MW: pebbles and a 3 XI TS w XI 13 IS UI ,o.-- magula10 aJngular: baJda are rwndd adare pee domin;ntly g;mcUante in oape urn; WySmclBsd. Covend in!-. slumped debns. - 0-2.- --- . __ _- ._-A-- _____-_I_-- Legend ------_ - -- - . - - -.- - .- hlud (~iltlclq)2:'; ~nvcl - Planar stratified --' , Massive . Imbricae Ripples Organics . ,------::.- Sand ,",- Diamicton -- Cross-smtificd 1- , Tmugh ~~~st~~titSed Fossils .* - kloditiers: c = cnde d = discontinuous ------I - - . . - - - - . - - . - . -. _- -. - .-I__------Wr~.2&0~9?Seaion numk LW-97-19 Maumiby: LW/L\l CreckaRjva: hblinGukh NTS: l06M hin1&6~?'0~"~hgirudr J 15.4~I i"WElevrian: 2930 Urn: J59850E710 t0110M Grain Size Remarks b Soning wpm- I8 - --...-. . - - . - . - -. . . . .- . - .. * I , * --... .. - , --- ... .. I -...... # : 1 ? , , -. - .. 1o.E- I ( - ,j; . .. I !, I - ...... I I 1,, i -::.:::: t I 1 i -, --- ...... J - . . --...*... . Very~l~poarhlxnad.~ SuoOar~~ecobbie~ w-ed boulda(colrmun); -aean@wtom ~thanS%suomu&d~a)., ~*straldiedurueas.tutro( ww-mv-ed n-- a namr upanc.m~~JIS; -wODdy-sanered =a mad mot(1ednW. Feagnnpsweakadconcen- lntrd abad Wcra uganc. nchyl(leMes ID ~mrsooan~m I Cowred mterval. slu- dam ------= Legend - Y -.- -7 - - .--, Mud (Silffclay) Gmel -= Pln+stntiticd 5 Massive - Imbricate -- Rippla i\ Or-its ------'-.:-.! Sand ,'; Diamicton Cross-stmtifkd Trough cross-stratified ' - Fossils + - - - - hloditias: c = crude d = discontinuous Datw@~f%mion number LW-97-20 Measured by: LW/Lhf C& a~iva:DublinGulch Fm: 106M IarirudrSM)Z'OO"N Longitudcl~~*49'41 Elcviyion: 28 10 UTM: 459500E.7 10087SN Grain Size gLn -d Remarks Drnc.?I;OpJ Smion number. LW-97-20 Musurd by: LW/LM C~IX~bva: Dublin Gulch NT5: 106M Ljtrrudcw'OO*pJ ~onginrdc:J~*39'4I"WElmnon: 28 10 ml: ~59500E7I0087SN On'ar~lron: Za ' ------064' ~morpht~l;mdf-: Gulch GnveVCoIlwid Apmn -rn -rn gVI VI Grain Size 2 I - a Texture L U 6 m u L Remarks 6 C Som'ng Q f - qpmr '0 .- 2 <5 Lqcnd ------1% - - .-, Mud (SilVclay) Gravel -= Plmu smtificd Massive - Imbricate - Ripple & Omits 7 - - 7 - :: i:.. Smd A- ,":- Dimicton - Cross-sujtiticd - Trough cross-stratified -- Fossils . NOTE TO USERS Oversize maps and charts are microfilmed in sections in the following manner: LEFT TO RIGHT, TOP TO BOTTOM, WITH SMALL OVERLAPS UMI ,-' 1' -. -"I \ c\. -:sfIfl4 . r4 -7 Beauvette Hill '* $4 FIGURE 1.2: I E 1.2: LOCATION OF HAGGART CREEK STUDY AREA MAY0 AREA, CENTRAL YUKON SCALE 1:250 000 RECQMMENDED CITATION m.J.D.. lsee. MapAtem Lrxaial Mlp. ~and~~U,~and~adrem~aks.~aneda~~aptseem 1:250,00[rscalemep. 30' IS' FIGURE 1.2: L ONE THOUSAND METRE Universal Transverse ME#W!CK Grid ZONE 8 : LOCATION OF HAGGART CREEK STUDY AREA MAY0 AREA, CENTRAL YUKON SCALE 1:250 000 CONTOUR INTERVAL 500 fTET Elevations in feet atme Mean Sea hl NorthAmericanDatum 1983 Transversa hbrcatoc Projedian RECOMMENDED CITATION . NOTE TO USERS Oversize maps and cham are microfilmed in sections in the following manner: LEFT TO RIGHT, TOP TO BOTTOM, WITH SMALL OVERLAPS . -- Government LEGEND LEGEND McCanell~Limft(>23a#BP) (defined appooomele) .....-.-...... -.-...... -..-...... --..-.-...... -.-I' Reid Icefbw Dirsdbn...... -...... -..-. .-...... -....- ...... -.... P'd ~eid~h(>rnoa)BP) ,--- # (eppor6neo8).-.------..- ...... -...-....-...... *-. -.-..-.-.-..--.-.-...... 0 .*..... =*- d'# 'L9ZE.mL8Bq VBEL89Lge 'Ud S82 VMWA ' -lSrreyYCJOE m~umcc-uawc.spoNeuwuoW(InawSmplex*-p, ~ul~uay~aq~~uoyl~paladar~eyl'~w~sado3 .- ~QUO'OS.r '-1 deyy 83mQS-9 'w-3'~w~ple~pll'uolsrruosglvue~~pue~ .~/omtm 'wnA pllue3 'm~qm lowmYm3 '8661 "O'r 'am FIGURE 3.2: ONE MOOSAND METRE lJrliversalT~~o~Grid ZONE 0 w FILL.lh. Rc 136'00' 45' 30' 1 3.2: GLACIAL LIMITS AND ICE FLOW PATTERNS MAYO AREA, CENTRAL YUKON SCALE 1:250 000 t 0 20 30 40 CONTOUR INTERVAL 500 FEET Ehathsin feet abow Mean Sea Leuel North~Oatum1983 ~~MercatorPr~ RECOMMENDED CITATION BOND. J.D.. 1998. Glaaal CmRs end loe Flow Panems. Mayo Area. Cenael Yukon. ExWam end Gmbw~IServices Oii.Misn and NoRhem Affairs. Canede Geacmce H8p 1994777 r ,250.0009cale map. Copes of thrs map, Ihe accompenylngrepat and Yukon Minfile may be pPchased fmGeosaenoe lntorrnation and Seles. E@M&II and Geobgld Se~ceshsim. I* and Northem Mars C8nadq Roan 1CR. 300 M8n 8.Whirehcrse. YMY1A 285 Ph. 867-667-3284 Fax 887-687-3267 Kespthomepstaedinadakareetoprmrnmepcohrshanledng. Ths mep was relegsed May 1999: subsequent revruon dales are: Geoscience Map 1999-? GLACIALLIMITS AND ICE FLOW PATTERNS MAY0 AREA, CENTRAL YUKON J.D. Bond y--%F=n . NOTE TO USERS Oversize maps and charts are microfilmed in sections in the following manner: LEFT TO RIGHT, TOP TO BOTTOM, WITH SMALL OVERLAPS ':., 2750 ft. '\ 838 rn. Covered; depth to bedrock approximately 9 m (?). Holocene Colluvium Covered; depth to bedrock approximately 9 rn (?). Holocene Colluvium keid Outwash Covered; depth to bedrock approximately 3.5 m (?). Covered; depth to bedrock approximately 9 nn (?). Om 200 m 400 m 600 m 800 m Figure 8.37: Stratigraphic correlation of Dublin Gulch. Flow of Dublin Gulch is from left to right. . NOTE TO USERS Oversize maps and charts are microfilmed in sections in the following manner: LEFT TO RIGHT, TOP TO BOTTOM, WITH SMALL OVERLAPS 1' f- Covert Haggart Creek prokna braided river gu&el (reworked toe, of McConne&periglacial fan fiomGill Gulch) Bedrock (? L Recent Holocene coliuvium Post-McConnell to early LW-97- I4 Holocene colluvium (organic- rich colluviated loess) * Bedrock (?) Post McConneH-wandering Gill 3 gravel bed river of paleo Haggm Creek Bedrock I n I I I I 1 1 I I Om 100 200 300 400 i Figure 8.38: Stratigraphic correlation of Haggart Creek near Gill Gulch. Flow of Haggart Creek is from rig1 /. gart Creek pro&na~ ded river gcllvel vorked toe'of Zome&periglacial fiomGill Gulch) ne colluvium :11 to early lvium (organic- iloess) I1 wandering Gill 3 r of paleo hic correlation of Haggart Creek near Gill Gulch. Flow of Haggart Creek is from right to left . NOTE TO USERS Oversize maps and charts are microfilmed in sections in the following manner: LEFT TO RIGHT, TOP TO BOTTOM, WITH SMALL OVERLAPS Proximal braided stream (infmed age is McConqeii Recent Holocene col luvium Early Holocene organic-rich silt (colluvium). Wandering grave1 bed river (inferred age is Post-McConnell) Medial to distal braided stream (inferred age is McConnell) Bedrock (?) I I I 200 400 600 rrelation of Haggart Creek downstream of Platinum Gulch. Flow of Haggart Creek is from left to right. . NOTE TO USERS Oversize maps and charts are microfilmed in sections in the following manner: LEFT TO RIGHT, TOP TO BOTTOM, WITH SMALL OVERLAPS Om I I 1 1 1 I 1 I Om 50 100 150 200 Figure 8.40: Stratigraphic correlation of Haggart Creek, on right-limit near 15 Pup. Flow of Haggart Cr left. Covered (slumped debris) --. paQnne1 wandering -'- I 1 1 I I I I I I 50 100 150 200 250 : ~tratiba~hiccorrelation of Haggart Creek, on right-limit near 15 Pup. Flow of Haggar? wkis from right to