Unnamed (south of Flat Creek)

Prospect in Alaska, United States with commodities Copper, Gold, Lead, Tungsten

Geologic information

Identification information

Deposit ID 10001153
MRDS ID A011849
Record type Site
Current site name Unnamed (south of Flat Creek)
Related records 10308499

Geographic coordinates

Geographic coordinates: -144.13263, 62.72968 (WGS84)
Relative position The site consists of several occurrences near an unnamed prospect (Cobb, 1979 [OFR 79-1247, p. 30] on the north side of the center part of the broad ridge between Cobb Lakes and Flat Creek. The broad ridge was called the Grizzly Hills by Kirk Stanley (written communication, 2000). The prospects are about 0.4 miles, south-southwest of a prospect mapped by Richter (1966, fig. 5). It is within a broad lead-zinc geochemical anomaly defined by Richter (1966) and a nearly coincident, gold geochemical anomaly defined by WGM Inc. (WGM Inc., 1980; anomaly 3a). The locality is approximately the same as number 11 of Richter and Matson (1972), and number 27 of MacKevett and Holloway (1977). The occurrences are in the NE1/4SE1/4, section 17, T. 11 N,. R. 7 E., Copper River Meridian.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Gold Secondary
Lead Secondary
Tungsten Secondary

Comments on the commodity information

  • Gangue = Carbonate

Materials information

Materials Type of material
Chalcopyrite Ore
Quartz Gangue
Tourmaline Gangue

Alteration

  • (Local) Tourmaline.

Mineral occurrence model information

Model code 79
USGS model code 21a
Deposit model name Porphyry Cu-Mo
Mark3 model number 2

Nearby scientific data

(1) -144.13263, 62.72968

Comments on the geologic information

  • Geologic Description = The area consists mainly of the Grubstake, medium-grained quartz monzonite phase of the Pennsylvanian to Permian, Ahtell pluton and its quartz-rich border phase (Richter, 1966). The area has widespread mineralization. Richter (1966 fig. 5) mapped a prospect with a sulfide-bearing quartz-carbonate vein at an elevation of about 3,400 feet in the drainage north of the ridge. Rocks nearby contain disseminated chalcopyrite. WGM Inc. (WGM Inc., 1980) mapped a half-mile-long altered area containing sulfide veins centered on this location. Stream sediments in the drainage below Richter's prospect contained 700 ppb gold and the south-draining stream from the ridge contained 300 ppm tungsten. Kirk Stanley (written communication, 2000) reported the existence of tourmaline and silver-lead veins on the Grizzly Hills but without specifying an exact location.
  • Age = Emplaced subseqent to or is related to the border phase of the Pennsylvanian to Permian, Ahtell pluton.
  • Age = Probably coeval with a Jurassic diorite to quartz-diorite complex.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Chistochina

Comments on the workings information

  • Workings / Exploration = The area has been explored intermittently by reconnaissance mapping, sampling, and minor bulldozer trenching since about 1963.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A011849
USGS Alaska Resource Data File ARDF GU010

Bibliographic references

  • Deposit

    Richter, D.H., 1966, Geology of the Slana district on south-central Alaska: Alaska Division of Geological and Geophysical Surveys Geological Report 2l, 36b p., 3 sheets, scale 1:63,360.

  • Deposit

    Richter, D.H., and Matson, N.A., 1968, Distribution of gold and some base metals in the Slana area, eastern Alaska Range, Alaska: U.S. Geological Survey Circular 593, 20 p.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.

  • Deposit

    Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Gulkana quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-1247, 36 p.

  • Deposit

    WGM Inc., 1980, 1979 Summary report of gold potential, Slana District, Ahtna project: WGM Inc., 10 p., 1:63,360-scale map. (Report held by Ahtna Mineral Co., Anchorage, Alaska).

  • Deposit

    Richter, D.H., and Matson, N.A., Jr., 1972, Metallic mineral resources map of the Gulkana quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-419, 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Richter, 1966

General comments

Subject category Comment text
Deposit Model Name = Polymetallic vein (Cox and Singer, 1986; model 22c)
Deposit Other Comments = Additional information can be obtained from Ahtna Minerals in Anchorage, Alaska.

Reporter information

Type Date Name Affiliation Comment
Reporter 06-DEC-00 W.T. Ellis Alaska Earth Sciences
Reporter 06-DEC-00 Hawley, C.C. Hawley Resource Group
Reporter 06-DEC-00 W.J. Nokleberg U.S. Geological Survey