Unnamed (near headwaters of Midnight Creek)

Occurrence in Alaska, United States with commodities Silver, Gold, Lead, Copper, Zinc

Geologic information

Identification information

Deposit ID 10307268
Record type Site
Current site name Unnamed (near headwaters of Midnight Creek)

Geographic coordinates

Geographic coordinates: -164.52342, 65.79933 (WGS84)
Relative position This location is 1,500 feet east of the headwaters of Midnight Creek, a north tributary to Taylor Creek. It is a flat southeast-trending spur at 1,950 feet elevation that is 8,000 to 8,500 feet east of elevation 2,370 feet on the continental divide. The continental divide separates the headwaters of Hot Springs Creek and Midnight Creek.
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Geographic areas

Country State
United States Alaska

Commodities

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

Comments on the commodity information

  • Gangue = Iron-oxides

Materials information

Materials Type of material
Quartz Gangue

Alteration

  • (Local) Quartz veining and iron-oxide fracture fillings and staining are common. There may have been some clay development. Unoxidized mineralization probably contains pyrite and base metal sulfides.

Mineral occurrence model information

Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Nearby scientific data

(1) -164.52342, 65.79933

Comments on the geologic information

  • Geologic Description = A linear altered zone in polydeformed metapelitic schist of possible Precambrian age (Till and others, 1986) trends about N 55 W across this spur. Sainsbury and others (1970) indicate that rusty graphitic schist and quartz vein fragments are present over a length of 2,000 feet. A sample of iron-stained fracture fillings contained 0.8 ppm Au, 700 ppm Ag, 10,000 ppm As, 1,500 ppm Cu, greater than 10,000 ppm Pb, 150 ppm Sb, and 5,000 ppm Zn. A composite grab sample of surface float collected along 300 feet of the altered zone contained 0.02 ppm gold, 3 ppm Ag, 300 ppm As, 150 ppm Cu, 1,500 ppm Pb, and 500 ppm Zn (Sainsbury and others, 1970, Table 2). The altered zone is probably developed along a high-angle fault. This occurrence, and other nearby occurrences in the headwaters of Humbolt and Ferndale Creeks to the north (BN049-BN052), are interpreted to be structurally above subsurface extensions of the Oonatut Granite Complex (Hudson, 1979). The Oonatut Granite outcrops 2.5 miles to the northwest of this occurrence. This large exposed granite complex is part of the western Seward Peninsula tin-granite suite (Hudson and Arth, 1983). Sainsbury and others (1970, p. H8) suggest that the polymetallic character of the mineralization in this altered zone is similar to what is found in the peripheral silver zone of tin deposit systems. However, only pan concentrate samples from this occurrence had anomalous tin values (to 200 ppm, Sainsbury and others, 1970, Table 2).
  • Age = Probably Late Cretaceous; this occurrence may be associated with emplacement and crystallization of the Oonatut Granite Complex. K/Ar ages for the Oonatut Granite Complex are about 70 my (Hudson, 1979).

Economic information

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name Kougarok

Comments on the workings information

  • Workings / Exploration = Shallow hand-dug prospect pits may be present.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF BN048

Bibliographic references

  • Deposit

    Hudson, T.L., 1979, Igneous and metamorphic rocks of the Serpentine Hot Springs area, Alaska: U.S. Geological Survey Professional paper 1079, 27 p.

  • Deposit

    Hudson, T.L., and Arth, J. G., 1983, Tin-granites of Seward Peninsula, Alaska: Geological Society of America Bulletin, v. 94, p. 768-790.

  • Deposit

    Till, A.B., Dumoulin, J.A., Gamble, B. ., Kaufman, D.S., and Carroll, P.I., 1986, Preliminary geologic map and fossil data, Soloman, Bendeleben, and southern Kotzebue quadrangles, Seward Peninsula, Alaska: U.S. Geological Survey Open-File Report 86-276, 10 p., 3 plates, scale 1:250,000.

  • Deposit

    Sainsbury, C.L., Hudson, T.L., Kachadoorian, Reuben, Smith, T.E., Richards, T.R., and Todd, W.C., 1970, Geology, mineral deposits, and geochemical and radiometric anomalies, Serpentine Hot Springs area, Seward Peninsula, Alaska: U.S. Geological Survey Bulletin 1312-H, p. H1-H19.

Comments on the references

  • Primary Reference = Sainsbury and others, 1970

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins developed peripheral to tin deposits

Reporter information

Type Date Name Affiliation Comment
Reporter 15-MAR-99 Travis L. Hudson Applied Geology