UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary U *L>. GEOLOGICAL SURVEY " W. C. Mcndenhall, Director Bulletin 926 MINERAL RESOURCES OF ALASKA REPORT ON PROGRESS OF INVESTIGATIONS IN 1939 PAPERS BY PHILIP S. SMITH, FRED H. MOFFIT AND F. F. BARNES l«.,0 " 1 UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1942 'j ^ CONTENTS {The letters in parentheses preceding the titles are those used to designate the papers for advance publication] Page (A) Mineral industry of Alaska in 1939, by Philip S. Smith_____ .._._. 1 (B) Geology of the Gerstle River district, Alaska, with a report on the Black Rapids Glacier, by Fred H. Moffit...____________________ 107 (C) Occurences of molybdenum minerals in Alaska, by Philip S. Smith.._ 161 (D) Geology of the Portage Pass area, Alaska, by F. F. Barnes.________ 211 ILLUSTRATIONS Page PLATE 1. Map of Alaska, showing areas covered by selected available reports and maps of Alaska_____---_-___.______ ..____ In pocket 2. Topographic reconnaissance map of the Gerstle River district, Alaska _ _______________ _____l_______-_-__________ In pocket 3. Geologic reconnaissance map of the Gerstle River district. In pocket 4. View southeast across Jarvis Creek Glacier from mountain top 3 miles east of Rapids Roadhouse--_-----_.--_-_----__--__ 110 5. A, Smooth, round-topped mountains east of Johnson River .near northern border of highland area; B, Donnelly Dome from a point 3 miles to the southwest. _.-.____- _ ._._.____ Ill- 6. A, Bed of white quartz fragments at base of Tertiary coal- bearing deposits near head of Little Gold Creek; B, White quartz bed that forms base of Tertiary deposits near head of Little Gold Creek.. ____________________________________ 134 7. A, Beds of coal in sandstone and sandy shale on small tributary of Jarvis Creek west of Little Gold Creek; B, Nenana gravel on Macomber Creek a short distance below mouth of Old Channel Creek. .... __.____...______.__.___.._.________ . 134 8. A, Gravel deposits on east side of Gerstle River near the canyon; B, Tilted gravel beds- (Nenana) near margin of highland area west of Gerstle River; C, Morainal deposits at margin of Tanana lowlands 8 miles northwest of Gerstle River_.___ _______ ___!___ _____________________________ 134 9. A, Weathered masses of schistose granite on ridge west of Gerstle River, 2^ miles northeast of Bradford Creek; B, Boulder-strewn bed of Sheep Creek _._.._.__.__.__.__.__.. 135 10. A, Black Rapids Glacier from brow of gravel terrace above Richardson Highway, about 100 yards south of Rapidg Roadhouse ; B, End of Black Rapids Glacier ______________ 150 11. Black Rapids Glacier from point on gravel terrace above Richardson Highway, 2.1 miles south of Rapids Roadhouse. 151 12. Map of Alaska showing localities where molybdenum minerals have been found _ -___-_--_-_-___-_-_-_---__-_-_______ 164 III wwe<^ IV . CONTENTS PLATE 13. Regional map showing general relations of Portage Pass area, Alaska _____-_--_-___-______-__-_-___-----____----_-__ 214 14. A, East slope of Portage Shoulder from head of Passage Canal; B, View west from Portage Shoulder down Portage Valley. 222" 15. South slope of Portage Shoulder__--________-__-------_____ 222 16. Geologic map of the Portage Pass area._-___-___-_______.__ 226 17. A, Breccial of argillite fragments in matrix of graywacke on west slope of Portage Shoulder; B, Lower part of Portage Glacier, from Turnagain Shoulder________________________ 230 18. Ne"ve" fields and upper part of Portage Glacier, from Portage Shoulder _-------______________-________--_-__---_--_ 230 19. Whittier Glacier, as seen from Passage Canal: A, In 1914; B, In 1940.- _ _-_-__--___-_._._...._.__.-._... 230 20. View across head of Passage Canal from the southeast, showing Learnard Glacier: A, In 1914; B, In 1940_-___------__-_- 234 21. A, Debris-covered ice ridges below Learnard Glacier, as seen from foot of Portage Shoulder in 1914; B, West slope of Portage Shoulder, showing large fold in beds of slate and graywacke. ________ _________________________________ 234 FIGTTBE 1. Trends of mineral production of Alaska, 1890-1939._-----___ 11 2. Trend of value of gold production of Alaska, 1880-1939______ 14 3. Copper produced from Alaska mines, 1900-1939, and fluctua­ tions in the price of copper during that period____-__. _____ 80 4. Index map of part of Alaska showing the location of the Gerstle River district___________________________^.-_____________ 108 5. Map of drainage basin of Black Rapids Glacier as surveyed by J. W. Bagley in 1910_.____-_-______._____'_________ 150 6. Lower part of Black Rapids Glacier as surveyed by T. W. Ranta in 1937_______________________________________ 150 7. Index map showing location of Portage Pass area.-._________ 212 UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary GEOLOGICAL SURVEY W. C. Mendenhall, Director Bulletin 926-A MINERAL INDUSTRY OF ALASKA IN 1939 BY PHILIP S. SMITH Mineral Resources of Alaska, 1939 (Pages 1-97) UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1941 For sale by the Superintendent of Documents, Washington, D. C. - - - Price 20 cents CONTENTS ~*< ' ' Page Introduction.______________.____-----------_--_-_----_-_-__- --__-_ 1 Acknowledgments. _ _____________----------_----------_---_---_---_ 5 Mineral-,production. ____________.-_______-___-___-_-_-_-_-___-_---_ 5 +4* . General features of the year-___--_--__-_-----------___-_-----_-_ 5 Total mineral production.______________________________________ 9 Gold.-.-.---.--------.--------------------------------------- 12 General features..._______-------_--_-------------__--_---_ 12 Gold lodes-.---.---.--.------------------------------------ 16 Gold placers.___________---_---__-__-___-_-_-_-_-__--__--_ 28 General conditions.-------------------------.---------- 28 > Production by districts-----_----_-.---._--.--_-__--__-_ 31 Southeastern Alaska.______________________________ 33 Copper River region__.--_.._--_---_-------_..------_ 33 Cook Inlet-Susitna region.---.--------------.------- 35 Yukon region.__--_---_-_-__-.-.-.-.-.-_.._--_-___ 38 Kuskokwim region.___________:.____________________ 54 Seward Peninsula---.-----.________________________ 58 Northwestern Alaska_____________________________ 66 Dredging--..._.___.------____________________________ 68 -^ SUyer-.----.-,----..--..--__------.--.-------.---.-...__----.- 72 Platinum metals_____-__-__-__---__-__--___-__--__.___--_-___ 75 Copper_____________________________________________________ 78 Lead_______________________________________________________ 81 Tin-____.--_--_---_-___-___--_--___-_-___-_-_-_-.___._-__-___ 82 Coal______.__________________________________________________ 85 Petroleum. _ ____________________________________________________ 89 Miscellaneous mineral products________________________________ 92 Index__________________________________'__________________________ 99 Selected list of Geological Survey publications on Alaska. On back of map in pocket PLATE 1. Map of Alaska, showing areas covered by selected available reports and maps of Alaska__________________________ In pocket FIGURE 1. Trends of mineral production of Alaska, 1890-1939.___..--__ 11 2. Trend of value of gold production.of Alaska, 1880-1939__._ 14 3. Copper produced from Alaska mines, 1900-1939, and fluctua­ tions in the price of copper during that period_____________ 80 MINERAL INDUSTRY OF ALASKA IN 1939 By PHILIP S. SMITH l The presentation of a yearly record of the Alaska mineral industry is a continuing service that has been rendered by the Geological Survey from almost the earliest years of extensive mining in Alaska, and the present report, for 1939, is the thirty-sixth of this series.3 Such a record, especially when supplemented by the statistics for the pre­ ceding years, not only affords an authoritative summary of current and past conditions but also indicates trends that are of significance in suggesting the lines along which future developments of the indus­ try are likely to proceed. These reports therefore serve miners, pros­ pectors, and businessmen concerned with Alaska affairs as useful historical records, statements of contemporary conditions, and starting points on which some conjectures concerning future operations may be predicated. To obtain the information recorded in these reports the Geologi­ cal Survey, in addition to its other investigations of mineral resources, conducts an annual canvass of the entire mineral industry of Alaska. The collection of the facts requisite for the preparation of these annual statements involves difficulties, because the great size of the Territory, the diversity of its mineral products, and the large number but small size of many of the enterprises make it impracticable without undue delay and expense to gather all the desired information at first hand. The information used is therefore derived from many sources, which necessarily vary in reliability and completeness. Efforts are made, however, to reduce all the statements to a comparable basis and to 1 The canvass of producers, the tabulation of their replies, and general assistance in all phases of the office work connected with the preparation of the statistics set forth in this report have been carried through effectively by Kathleen S. Waldron, of the Alaskan branch of the Geological Survey. 2 The other volumes of this series, commencing with that for 1904, are Bulletins 259, 284, 314, 345, 379, 442, 480, 520, 542, 992, 622, 642, 662, 692, 712, 722, 739, 755, 773, 783, 792, 810, 813, 824, 836, 844-A, 857-A, 864-A, 868-A, 880-A, 897-A, 910-A, and 917-A. The reports for 1902 and 1903 Avere included with other "contributions to eco­ nomic geology" in Bulletins 213 and 225. 2 MINERAL RESOURCES 0>F ALASKA, 1939 give only those that appear to be well substantiated. Among the most reliable sources of information are the geologists and engineers who are sent out each year by the Geological Survey to conduct surveys in different parts of Alaska and who acquire not only much accurate information regarding the mineral production of the regions in which they work but also general information by contact with miners and operators in the course of their travels to and from the field.