Silver Creek

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

Geologic information

Identification information

Deposit ID 10001148
MRDS ID A011842
Record type Site
Current site name Silver Creek
Related records 10185464

Geographic coordinates

Geographic coordinates: -144.05762, 62.73274 (WGS84)
Relative position The Silver Creek prospect (Cobb, 1979 [OFR 79-1247]) is at an elevation of about 2,800 feet in Silver Creek about 1/2 mile above its junction with Ahtell Creek . The location is number 8 of Richter (1966; fig. 5), locality 12 of Richter and Matson (1972), and locality 11 of MacKevett and Holloway (1977). The location is accurate to within 500 feet; it is the NW1/4SW1/4, section 14, T. 11 N., R. 7 E., Copper River Meridian.
(click for info)

Geographic areas

Country State
United States Alaska

Commodities

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

Comments on the commodity information

  • Gangue = Carbonate

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Limonite Ore
Malachite Ore
Pyrite Ore
Sphalerite Ore
Tetrahedrite Ore
Quartz Gangue

Alteration

  • (Local) Country rocks near veins are altered to carbonates and are iron-stained; hornfels in the fault zone has been argillized and pyritized.

Mineral occurrence model information

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

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Hornfels
    Rock unit name Tetelna Formation
    Rock description Tetelna Formation
    Stratigraphic age (youngest) Late Permian
    Stratigraphic age (youngest) Late Permian

Nearby scientific data

(1) -144.05762, 62.73274

Comments on the geologic information

  • Geologic Description = The Silver Creek prospect consists of highly altered, pyritic rock and veins that occur along cross-fractures to a major fault zone. The fault zone is 100 or more feet wide, strikes N 10-20 E and dips 65 to 80 degrees to the west. The fault appears to cut and displace a dike-like Jurassic(?) diorite that intrudes sedimentary and volcanic rocks of the Pennsylvanian to Permian, Slana Spur Formation (Richter 1964; 1966; Richter, Lanphere, and Matson, 1975; and Kirk Stanley, written communication, 2000).? Rocks within the fault zone are yellowish, carbonate- and gouge-rich hornfels that contain fine-grained disseminated pyrite. Quartz-carbonate veins as much as five-feet thick cross the fault zone; veins locally contain concentrations of galena, tetrahedrite, chalcopyrite, pyrite, and sphalerite. Limonite and malachite are abundant in near surface exposures (Thorne, 1946; Richter, 1966; Kirk Stanley, written communication, 2000).? Individual cross-veins described by Richter (1964; 1966, p. 32-33) strike NW and dip NE. Locally, they are enriched in silver, probably mainly in tetrahedrite. Thorne (1946, p. 8, fig. 4) reported that a one-foot-thick vein from the uppermost workings assayed a trace of gold, 17.5 ounces of silver per ton, some lead, and 1.59 percent copper. Another sample from caved workings contained 0.04 ounce of gold per ton with only a trace of copper. The prospect was reopened and drilled in about 1969-70. Samples collected from small diameter (AX) drill holes locally contained more than 50 ounce of silver per ton. Low-angle BX holes drilled across the veins encountered occasional high silver values, but indicated that the average grade across the fault zone was less than 5 ounces of silver per ton. No substantial work has been done since 1970 (Kirk Stanley, written communication, 2000).
  • Age = Emplaced subseqent to or is related to the border phase of the Pennsylvanian to Permian, Ahtell pluton.

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 prospect has been known since about 1908 (Kirk Stanley, written communication, 2000). When visited by Moffit (1938) and Thorne (1946), most workings were caved. Renewed interest in the prospect began about 1962 and continued until about 1970, the property was trenched beginning in 1962, and drilled by the Ptarmigan Company in 1969 or 1970. It has been inactive since.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A011842
USGS Alaska Resource Data File ARDF GU011

Bibliographic references

  • Deposit

    Thorne, R.L., 1946, Exploration of argentiferous lead-copper deposits of the Slana district, Alaska: U.S. Bureau of Mines Report of Investigations 3940, 9 p.

  • Deposit

    Richter, D.H., 1964, Geology and mineral deposits of the Ahtell Creek area, Slana District, south-central Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 6, 17 p., 1 sheet, scale 1:31,680.

  • 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

    Richter, D.H., Lanphere, M.A., and Matson, N. A., Jr., 1975, Granite plutonism and metamorphism, Eastern Alaska Range, Alaska: Geological Society of American Bulletin, v. 86, p. 819-820.

  • 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

    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

    Moffit, F.H., 1938, Geology of the Slana-Tok district, Alaska: U.S. Geological Survey Bulletin 904, 54 p.

  • 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 = the most recent exploration data on the property was summarized in: 'Slana Mineral Belt Prospects Review' by Kirk Stanley, a report for Ahtna Minerals Corporation (Wes Nason, Ahtna Minerals, written communication, 2000). Additional information can be obtained from Ahtna Minerals in Anchorage, Alaska.

Reporter information

Type Date Name Affiliation Comment
Reporter 05-DEC-00 W.T. Ellis Alaska Earth Sciences
Reporter 05-DEC-00 Hawley, C.C. Hawley Resource Group
Reporter 05-DEC-00 W.J. Nokleberg U.S. Geological Survey