Seward Gold

Prospect, Inactive

Alternative names

Telluride

Commodities and mineralogy

Main commodities Ag; Au
Other commodities As; Pb; Zn
Ore minerals arsenopyrite; galena; gold; pyrite; sphalerite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale C-7
Latitude 60.6447
Longitude -149.2952
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of 4,250 feet on the divide betwee the two forks of Groundhog Creek. It is located in the NW1/4 section 4, T. 6 N., R. 1 E., of the Seward Meridian. This location is accurate to within a quarter of a mile. This is location 35 of Cobb and Richter (1972), location 24 of MacKevett and Holloway (1977), location 36 of Cobb and Tysdal (1980), and location S-268 of Jansons and others (1984).

Geologic setting

Geologic description

The deposit consists of auriferous, sulfide-bearing, quartz-calcite veins that fill fractures in a shear zone in slate of the Valdez Group of Late Cretaceous age. The zone is 5 to 6 feet wide and extends S80E between two pale-greenish porphyritic dikes (Johnson, 1912). Much of the quartz is coarsely crystalline and is accompanied by a small amount of calcite, along with arsenopyrite, galena, sphalerite, and gold. The vein material is weathered and decomposed and has been traced about a hundred feet. The vein dips steeply south, nearly vertically. A narrow streak of fault gouge lies along the hanging wall at the shear zone. The gold is free-milling or in the arsenopyrite and galena. Specimens from the outcrop contain visible free gold (Johnson, 1912).
The workings on this prospect consist of trenches and a 90-foot adit with 23 feet of winzes, a 12-foot crosscut, and a 15-foot shaft (Johnson, 1912). The adit collapsed in 1911 (Martin and others, 1915).
Geologic map unit (-149.297323162649, 60.6441187688884)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Cretaceous or younger; the veins cut rocks of the Valdez Group of Late Cretaceous age.

Production and reserves

Workings or exploration
The workings on this prospect consist of trenches and a 90-foot adit with 23 feet of winzes, a 12-foot crosscut, and a 15-foot shaft (Johnson, 1912). The adit collapsed in 1911 (Martin and others, 1915).
The U.S. Bureau of Mines examined the prospect and collected samples in 1981. Two chip samples assayed a trace and 0.02 ounces of gold per ton, and a trace and 0.23 ounces of silver per ton. Two selected grab samples assayed 0.79 and 0.99 ounce of gold per ton, and 0.08 and 0.46 ounce of silver per ton. A grab sample of dump material contained a trace of gold and 0.02 ounce of silver per ton (Jansons and others, 1984).
Indication of production None

References

MRDS Number A010525

References

Hoekzema, R.P., and Sherman, G.E., 1983, Mineral investigations in the Chugach National Forest, Alaska (Peninsula study area): U.S. Bureau of Mines in-house report; held at U.S. Bureau of Land Management Alaska State Office, Anchorage, 524 p.
Reporters Jeff A. Huber (Anchorage)
Last report date 1/25/2000