Final report - mineral resources of northern Alaska Item Type Technical Report Authors Heiner, L.E.; Wolff, E.N. Citation Heiner, L.E. and Wolff, E.N., 1968, Final report - mineral resources of northern Alaska: University of Alaska Mineral Industry Research Laboratory Report No. 16, 306 p., 4 sheets. Publisher University of Alaska Mineral Industry Research Laboratory Download date 05/10/2021 08:34:04 Link to Item http://hdl.handle.net/11122/1065 F l NAL RE PORT MINERAL RESOURCES OF NORTHERN ALASKA M.I. R.L. Report No. 16 Submitted to the NORTH Commission Mineral Industry Research Laboratory University of Alaska Lawrence E. Heiner Ernest N. Wofff Editors University of Alaska Colorado State University June, 1968 Reprinted October, 1969 ACKNOWLEDGEMENTS It would be impossible to name all those who have contributed information and ideas to this report, through discussions, correspondence, or through access to unpublished material. The debt to those who have published information is acknowledged in the text and in the list of references in the back of the report. In addition, James A. Williams, Director of the State Division of Mine and Minerals, and Gordon Herreid of the same office, have given much of their time, allowed access to Division files, and provided working space in their office. Earl H. Beistline, Dean of the College of Earth Sciences and Mineral Industry, has helped greatly in expediting the work. George Grye, U. S. Geological Survey, has been most helpful in supplying information on Survey activities. C. L. Sainsbury and Peter 0. Sandvik have contributed ideas through discussions. Alan Doyle, Carl Heflinger, Douglas B. Colp, and Eski l Anderson have supplied more recent information on many of the mines and prospects listed in Table 5. Robert M. Chapman and Florence F, Weber, of the College Alaska U. S. Geological Survey office have been very helpful in supplying Survey literature. SUMMARY Introduction PURPOSE. This is the final report on the work authorized on July 29, 1967, by the NORTH Commission. The purpose is to inventory mineral resources in northern Alaska and to de- lineate favorable mineral areas, insofar as possible. Later, a mineral policy study was added and a survey of available airborne geophysics. The Alaska Railroad made possible the large scale dredging at Fairbanks and became a feeder to all lnterior districts. It allowed the building of mi li tary bases during and after World War II . Freight moves predominantly north. Mining Regions and Mineral Commodities NORTHERN ALASKA REGION Resources are mainly mineral fuels. Coal bearing rocks underlie 27,000 square miles. Reserves of about 80 million barrels of oi 1 and 5-7 billion cubic feet of gas are known. A recent strike at Rudhoe Eay isvery encouraging. Extensive, though unexplored areas of low to medium grade phosphate rock occur. NORTHWESTERN ALASKA REGION Placer mining has been carried on in two areas on the Kobuk River. The major interest at present is the copper deposit of the Kennecott Copper Corporation at Bornite. No firm estimate of grade or reserves can be made now, but the deposit is very large, The area is being extensively prospected. YUKON RIVER REGION The Fairbanks district has been the largest producer in Alaska. The Manley and Rampart districts, west of Fairbanks, have moderate reserves of gold and placer tin. A lode-tin source has been sought, but has not been located. There is a large, virtually unprospected area between the Yukon and Koyukuk rivers, and two placer gold districts on the Koyukuk. The upper Koyukuk contains reserves of placer gold and small amounts of stibnite. The Chandalar district, west of the Koyukuk has reserves of relatively high grade gold quartz. One dredge is operating on the Hogatza River, near the head of the Kobuk. SWARD PENINSULA REGION This region contains widespread mineralization; it contains fair reserves of placer gold and possibilities for offshore gold placers. Tin- deposits are well know, but known reserves are limited in size. Past production- 2000 tons metal from placers, 350 tons from lode . Reserves- 36,750 tons tin at 0.2%-1.3% at Lost River. Few thousand tons at Ear Mountain and vicinity. Fluorite occurs at Lost River Production - none Reserves - 2 million tons of 50% fluorite Beryllium occurs with the fluorite and tin. Production - none Reserves - Indicated and inferred, 2 million tons of metal at 0.18% to 0.29% Be. "Large indicated and inferred reserves" at 0.04% to 0.07%~Be and up to 0.3% tin. Tungsten occurs with the tin at Lost River. Production - small Reserves - 63,350 units (20 lbs.) WO plus indicated ore at 0.60% 193,000 units of inferred ope at 0.5% W03 containing up to 1% tin. 130,000 units of inferred ore at 0.2% W03 and up to 0.4% tin. A -lead deposit is being drilled Graphite occurs in the Kigluaik Mountains Production - 270 tons Reserves - 50 tons sorted material; 65,000 tons of 52%, 300,000 tons of 10% Lode gold small reserves exist on the Seward Peninsula Possible lmmediate Tonnaaes PLACER GOLD A fair sized placer mine would require 80-100 tons of freight per season. COPPER AT BORNITE It is probable that the ultimate plans for production for this deposit have not yet been formulated. Based cn varying production rates the followi ng could be expected: At 500 tons per day of 1W copper, 45,700 tons of concentrate per year At 5,000 tons per day of 2.5% copper, li4OOO tons per year of concentrate At 10,000 tons per day of 1.5% copper, 137,000 tons per year of concentrate At 20,000 tons per day of 1% copper, 183,000 tons per year of concentrate COAL There are no immediate tonnages of coal. If coal with the right characteristics for blending can be located, a market exists in Japan for 1 million tons per year. GAS AND OIL Umiat - 70,000,000 barrels oi 1 Fish Creek - prospective oil field Gubik - 300 billion cubic feetgas Mead and Square Lake - prospective gas fields Geology of Western North America TECTONICS AND GEOLOGY OF NORTHWEST NORTH AMERICA Except for the Arctic Coast, Alaska is part of the Western Cordillera, the ranges of mountains and valleys that extend the length of the Americas. The Cordillera has yielded the great metallic bonanzas of the past, and is still producing. Most of the structures of the present Cordillera in North America have been formed in Mesozoic and Cenozoic time. This iv history was very closely followed in Alaska; in early Paleozoic time eugeosynclinal rocks were deposited in southern Alaska, and miogeosynclinal rocks in Central Alaska with a shoreline in northern Alaska. In late Paleozoic time the sequence moved northward. In Mesozoic time, geanticlinal areas raised4andgeosynclinals were depressed between them. In Cenozoic time there were further uplifts that gave Alaska its present shape. A composite map of northern Alaska (Plate I) was drafted from all known sources at a scale of 1: 1,000,000. Descriptions of all rock units and their distributions accompany the map. Favorable Areas Based on Geology During the formation of the Mesozoic geosyncli nes and geanticlines (inversions) it is postulated that deep fractures formed at their boundaries. Using these boundaries and the allignment of known faults, other lineations, and the distribution of igneous intrusions, certain areas are delineated as favorable for the formation of minerals. These are: Borders of Romanzof Mountai ns South side hooks Range east to Chandalar Line from Darby to Candle (W. Seward Peninsula) North side Ruby geonticline (Ruby to Chandatar) Length of Major fault (Unalakleet to Eagle) Axis of Kuskokwirn geosyncline (unconformity at base of Mwmic rocks occurred along this line before erosion) Margins of Kandik segment and Nation Arch It is also postulated that the presence of a placer deposit, especially a weak one, will signal a lode deposit . Favorable Areas Based on Statistical Evidence By comparing the areas and geology of Alaska, Canada, and Western United States, it appears that Alaska is underdeveloped and should be capable of much more mineral pro- duction. By comparing the geology of a control area in southwestern United States, Harris (1967) delineates several cells 20 miles square that statistically could contain high values of mineral wealth. Five of these cells could contain $400 million, and 16 of then, $100 mi tlion. Mineral Policy Any mineral policy adopted should recognize the traditional methods of acquisition of mining claims and leases, and also the unique nature of mineral deposits in that new ones cannot be grown. Costs of mining in northern and northwestern Alaska may run fifty percent more than in the Western U. S. and Canada. Direct deduction of exploration expenses and depletion allowances are the chief tax in- centives in the United States. In Canada, rapid depreciation, no capitol gains tax, a three year tax free period on new mines, and subsidies have created a very favorable climate for mini ng . The Canadian government has launched a northern exploration program in which companies can participate on a cooperative basis. There is also a comprehensive road building program inthe north. Alaska, the chief financial aids are 0. M. E. participating loans, prospectors' aid, and help on building access roads. A number of rules and customs are examined to determine their effect on the mining in- dustry. The prohibition on export of certain minerals, stringent financial ~les,the fixed price of gold, large land withdrawals, and anti-hydraulicking laws adversely affect mining in Alaska. The Canadian and Alaskan technical aids and services are comparable in kind, but Canada provides more. Education and research in geology and mining must be supported by the State, and more services and research by the Federal Government most be pushed for by the State.