Mulchatna

Occurrence in Alaska, United States with commodity Gold

Geologic information

Identification information

Deposit ID 10003591
MRDS ID A106349
Record type Site
Current site name Mulchatna

Geographic coordinates

Geographic coordinates: -155.69577, 60.47051 (WGS84)
Relative position About 13 km northeast of VABM Overlook, near where the southeast flowing Springway Creek enters the Mulchatna River. NW1/4 sec. 3, T. 4 N., R. 37 W., of the Seward Meridian. Locality is accurate to within 800 m.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary

Materials information

Materials Type of material
Gold Ore

Alteration

  • (Local) Not applicable

Mineral occurrence model information

Model code 119
USGS model code 39a
BC deposit profile C01. C02
Deposit model name Placer Au-PGE
Mark3 model number 54

Nearby scientific data

(1) -155.69577, 60.47051

Comments on the geologic information

  • Geologic Description = Spurr (1900) reported placer gold, too flaky and fine to save, 200 miles from mouth of river as early as 1890. Brooks (1904) reported gold has long been known in the upper reaches of the river. Placer said to yield $4-5 per day per man in 1903, but area too remote for mining. Cobb (1976) indicated he thought Brooks (in 1904 report) may have been discussing placers of Bonanza Creek.? the most abundant bedrock in the areas upstream of the claims is unit KJs (Nelson and others, 1983). Unit KJs is described as interbedded lithic graywacke, silty sandstone, black shale , and local conglomerate. Irregular quartz segregations and veinlets are locally present. Scattered stocks and locally abundant dikes of intermediate to felsic composition intrude these sedimentary rocks. Adjacent to some of the larger igneous bodies are narrow contact aureoles of pelitic hornfels. Unit KJs is intruded (locally) by various Cretaceous to Tertiary plutons. The plutons include quartz monzonite, grano-diorite, diorite, and rhyolite dikes. Also present is Unit Tv of Nelson and others (1983) which includes rhyolitic breccia, ash-flow tuff, flows, and intrusive rocks and subordinate mafic to intermediate flows. Potassium-argon ages for unit Tv range from 56.2 to 62.7 m.y. (Eakins and others, 1978).
  • Age = The placer gold is Quaternary, the source of gold could come from a variety of rocks with diverse ages.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Mining district

District name Bristol Bay

Comments on the production information

  • Production Notes = No production

Comments on the reserve resource information

  • Reserves = No reserves

Comments on the workings information

  • Workings / Exploration = Three placer gold claims noted in 1973 by the U.S. Bureau of Mines.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A106349
USGS Alaska Resource Data File ARDF LC023

Bibliographic references

  • Deposit

    Spurr, J.E., 1900, A reconnaissance in southwestern Alaska in 1898: U.S. Geological Survey 20th Annual Report, part 7, p. 31-264.?

  • Deposit

    Brooks, A.H., 1904, Placer mining in Alaska in 1903: U.S. Geological Survey Bulletin 225, p. 43-59.

  • Deposit

    Katz, F.J., 1910, Gold placers of the Mulchatna: U.S. Geological Survey Bulletin 442, 426 p.

  • Deposit

    Martin, G.C., and Katz, F.J., 1910, Outline of geology and mineral resources of the Iliamna and Clark lakes region: U.S. Geological Survey Bulletin 442, 426 p.

  • Deposit

    Cobb, E.H., 1973, Placer deposits of Alaska: U.S. Geological Survey Bulletin 1374, 213 p.

  • Deposit

    U.S. Bureau of Mines, 1973, Alaska 1:250,000-scale quadrangle map overlays showing mineral deposit locations, principal minerals, and number and type of claims: U.S. Bureau of Mines Open-File Report 20-73, 95 overlays (updated in 1986, 1987).

  • Deposit

    Eakins, G.R., Gilbert W.G., and Buntzen, T.K., 1978, Preliminary bedrock geology and mineral resource potential of west-central Lake Clark quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Open-File Report 118, 15 p.

  • Deposit

    Cobb, E.H., and Reed, B.L., 1981, Summaries of data on and lists of references to metallic and selected nonmetallic mineral occurrences in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska - Supplement to Open-File Report 76-485: U.S. Geological Survey Open-File Report 81-1343-A, 25 p.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-485, 101 p.

  • Deposit

    Smith, P.S., 1917, The Lake Clark-central Kuskokwim region, Alaska: U.S. Geological Survey Bulletin 655, 162 p.

  • Deposit

    Smith, P.S., 1915, Mineral resources of the Lake Clark-Iditarod region: U.S. Geological Survey Bulletin 622-H, p. 247-271.

Comments on the references

  • Primary Reference = U.S. Bureau of Mines, 1973

General comments

Subject category Comment text
Deposit Model Name = Placer Au (Cox and Singer, 1986; model 39a)
Deposit Other Comments = Cobb and Reed (1981) mention gold in most river bars of the Mulchatna River, with most prospecting occurring around the late 1890's or early 1900's.

Reporter information

Type Date Name Affiliation Comment
Reporter 15-JUN-1998 D.P. Bickerstaff U.S. Geological Survey