Summit

Prospect in Alaska, United States with commodities Silver, Gold, Copper, Lead, Antimony

Geologic information

Identification information

Deposit ID 10001771
MRDS ID A012561
Record type Site
Current site name Summit

Geographic coordinates

Geographic coordinates: -148.20329, 67.53974 (WGS84)
Relative position The Summit lode is at an elevation of about 4,800 feet, approximately 1/2 mile south of Little Squaw Peak, between Little Squaw Peak and peak 5072 (St. Marys Peak as shown on fig. 2 in Chipp, 1970) in SW1/4 sec. 3, T. 31 N., R. 3 W., of the Fairbanks Meridian. The location is accurate within a 1/4-mile radius.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Copper Secondary
Lead Secondary
Antimony Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Gold Ore
Scorodite Ore
Quartz Gangue

Alteration

  • (Local) Oxidation of vein material produces scorodite and limonite.

Mineral occurrence model information

Model code 273
USGS model code 36a
Deposit model name Low-sulfide Au-quartz vein
Mark3 model number 27

Host and associated rocks

  • Host or associated Host
    Stratigraphic age (youngest) Devonian

Nearby scientific data

(1) -148.20329, 67.53974

Comments on the geologic information

  • Geologic Description = The Summit lode is one of the four principal auriferous quartz vein systems in the Chandalar area. The Summit vein system, like the others in the area, is localized along steeply-dipping, northwest-trending normal faults in Devonian quartz-muscovite schist, phyllite, and quartzite, intruded by Devonian mafic sills and dikes (Chipp, 1970). In general, the veins in the Chandalar area are less than 10 feet thick and are discontinuous, pinching out within a few hundred feet or less. The veins are composed principally of white crystalline to microcrystalline quartz, and their sulfide content is generally less than 5 percent. The principal sulfides (in relative order of abundance) are arsenopyrite, galena, sphalerite, and pyrite. Scorodite and limonite occur commonly as oxidation products. The quartz veins exhibit evidence of shearing, indicating that the veins were emplaced before or during fault movement. Major structural features in the area include large-scale northeast-trending anticlines and synclines, northeast-trending thrusts, and the northwest-trending, high-angle cross faults.? the Summit lode follows the Summit fault and the strikes N80W and dips 75 to 80 degrees south. Early workings on the property exposed a vein 1.5 to 2 feet wide. A sample from these workings was reported to have assayed $54 of gold per ton (Maddren,1913). Dump samples of vein material collected by Chipp (1970) contained abundant arsenopyrite and scorodite in sheared and brecciated quartz; assays of these samples returned values of 0.5 to 6.6 ppm Au. Ashworth (1983) described two generations of quartz at the Summit lode. The older generation is coarsely crystalline, massive, white quartz. It is in the hanging wall and is as much as 4 feet wide. It contains less than 5 percent sulfides and little gold. The younger generation pinches and swells; it adjoins the older veins, but typically follows in the footwall. It is generally finer grained and contains bands accentuated by smeared graphite and arsenopyrite. Scorodite is common, and free gold occurs as blebs and occasional wires. ?The genesis of the gold deposits in the Chandalar district is still in question. Various authors have hypothesized genetic links to a variety of felsic and mafic igneous rocks from which the gold was remobilized during metamorphism (Mertie, 1925; Boadway, 1933; Chipp, 1970; Dillon, 1982).
  • Age = Middle Cretaceous based on arguments by Dillon (1982) that the age of emplacement of the gold-bearing quartz veins of the Koyukuk and Chandalar districts was between the Neocomian metamorphism of the Devonian host rocks and their erosional unroofing and cooling in Albian time.
  • Age = Host rock is Devonian.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Chandalar

Comments on the workings information

  • Workings / Exploration = Maddren (1913) reported a 54-foot-deep shaft and a 72-foot drift along the vein. Prospect pits have been dug along the Summit fault/vein system as far east as the pass between Big Creek and McClellan Creek and west along the spur going into Big Squaw Creek. Heiner and Wolff (1968) report that there was some development work in the 1950s and a small mill was established for the ore in the headwaters of Big Creek.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A012561
USGS Alaska Resource Data File ARDF CH041

Bibliographic references

  • Deposit

    Maddren, A.G., 1913, The Koyukuk-Chandalar region, Alaska: U.S. Geological Survey Bulletin 532, 119 p.

  • Deposit

    Mertie, J.B., Jr., 1925, Geology and gold placers of the Chandalar district, in Brooks, A.H., and others, Mineral resources of Alaska, report on progress of investigations in 1923: U.S. Geological Survey Bulletin 773, p. 215-263.

  • Deposit

    Boadway, E.A., 1932, Report on Sulzer properties, Chandalar, Alaska: Alaska Territorial Department of Mines Miscellaneous Report 31-6, 23 p., 4 sheets.

  • Deposit

    Boadway, E.A., 1933, Report on Mikado and Little Squaw veins, Chandalar, Alaska: Alaska Territorial Department of Mines Miscellaneous Report 31-7, 37 p.

  • Deposit

    Anderson, Eskil, 1944, Petrographic descriptions of rocks collected during 1944 field investigation in north-west Alaska, and lists of ore and rock samples and placer concentrates collected in northwestern and interior Alaska during 1945 field season: Alaska Territorial Department of Mines Miscellaneous Report 195-28, 76 p.

  • Deposit

    Holdsworth, P.R., 1952, Report of the Commissioner of Mines for the Biennium ended December 31, 1952: Alaska Territorial Department of Mines Annual Report 1952, 66 p.

  • Deposit

    Saunders, R.H., 1959, Silver-lead occurrences in the Fairbanks district: Alaska Territorial Department of Mines Miscellaneous Report 194-18, 19 p., 2 maps, scale 1:63,360.

  • Deposit

    Heiner, L.E., and Wolff, E.N., eds., 1968, Mineral resources of northern Alaska, Final report, submitted to the NORTH Commission: Mineral Industry Research Laboratory, University of Alaska, Report 16, 306 p.

  • Deposit

    Chipp, E.R., 1970, Geology and geochemistry of the Chandalar area, Brooks Range, Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 42, 39 p., 1 sheet, scale 1:36,000.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Chandalar quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-457, 1 sheet, scale 1:250,000.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Chandalar and Wiseman quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-340, 205 p.

  • Deposit

    Grybeck, D.J., 1977, Known mineral deposits of the Brooks Range, Alaska: US Geological Survey Open-File Report 77-166C, 41 p., 1 sheet, scale 1:1,000,000.

  • Deposit

    DeYoung, J.H., Jr., 1978, Mineral resources map of the Chandalar quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-878-B, 2 sheets, scale 1:250,000.

  • Deposit

    Reiser, H.N., Brosgi, W.P., De Young, J.H., Jr., Marsh, S.P., Hamilton, T.D., Cady, J.W., and Albert, N.R.D., 1979, The Alaskan Mineral Resource Assessment Program: Guide to information contained in the folio of geologic and mineral resource maps of the Chandalar quadrangle, Alaska: U.S. Geological Survey Circular 758, 23 p.

  • Deposit

    Dillon, J.T., 1982, Source of lode and placer gold deposits of the Chandalar and upper Koyukuk Districts: Alaska Division of Geological and Geophysical Surveys Open-File Report 158, 25 p., 1 sheet, scale 1:250,000.

  • Deposit

    Ashworth, K.K., 1983, Genesis of gold deposits at the Little Squaw mines, Chandalar mining district, Alaska: Bellingham, Washington, Western Washington University, M.Sc. thesis, 98 p.

  • Deposit

    Cobb, E.H., and Cruz, E.L., 1983, Summaries of data and lists of references to metallic and selected nonmetallic mineral deposits in the Chandalar quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-278, 91 p.

  • Deposit

    Bundtzen, T.K., Eakins, G.R., and Conwell, C.N., 1982, Review of Alaska mineral resources 1981: Alaska Division of Geological and Geophysical Surveys Annual Report 1981, 48 p.

  • Deposit

    Holdsworth, P.R., 1955, Report of the Commissioner of Mines for the biennium ended December 31, 1954: Alaska Territorial Department of Mines Annual Report 1954, 110 p.

Comments on the references

  • Primary Reference = Chipp, 1970

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Deposit Other Comments = See also: Mikado (CH045), Little Squaw(CH040), Star(CH042).

Reporter information

Type Date Name Affiliation Comment
Reporter 17-NOV-99 J.M. Britton U.S. Geological Survey