Shell

Prospect, Inactive

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale C-7
Latitude 60.6732
Longitude -149.5414
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is at an elevation of 3,800 to 4,250 feet in the NE1/4 section 25, T. 7 N., R. 2 W., of the Seward Meridian. It is on the divide between two south tributaries of Fresno Creek and is designated the Shell Mine on the 1994 U.S. Geological Survey Seward C-7 topographic map. This location is accurate to within a quarter of a mile. This is location 30 of MacKevett and Holloway (1977), location 43 of Cobb and Tysdal (1980), and location S-266 of Jansons and others (1984).

Geologic setting

Geologic description

The Shell prospect consists of several quartz veins and at least two mineralized(?) felsic dikes. One of the dikes is a continuation of the Gilpatrick dike of Eocene age. The main vein strikes N10 to 15E, dips steeply, and carries arsenopyrite, galena, pyrite, and gold. The quartz veins and felsic dikes cut slate and graywacke of the Valdez Group of Late Cretaceous age (Tysdal, 1978).
Workings consist of an adit at an elevation of 4,100 feet that is caved 70 feet from the portal, a shaft at 4,150 feet, and numerous dozer trenches and prospect pits (Hoekzema and Sherman, 1983).
Geologic map unit (-149.543548546011, 60.6726216650419)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Eocene or younger; the dike is probably Eocene.

Production and reserves

Workings or exploration
Prospect pits in the area were reported as early as 1931 (Tuck, 1933). In the 1950s, there was caterpillar prospecting and possible construction of a cabin. The U.S. Bureau of mines examined and sampled the prospect in 1979 and 1981. They found an adit at an elevation of 4,100 feet that is caved 70 feet from the portal, a shaft at 4,150 feet, and numerous dozer trenches and prospect pits (Hoekzema and Sherman, 1983). Improvements included two standing buildings and a cat trail.
The adit was driven to intersect the shaft and is caved at that intersection (Jansons and others, 1984). The Bureau could not sample the main vein underground due to caving or on the surface because of snow cover. Pits along the trend of the vein indicate a strike length of at least 100 feet. Other quartz veins were examined briefly, but none contained significant ore minerals. Visible gold occurs in quartz piled on the surface near the shaft. The deposit appears to be of low grade.
Indication of production None
Reserve estimates Reserves were estimated by the U.S. Bureau of Mines at 440 tons at 0.4 ounce of gold per ton and 0.3 ounce of silver per ton (Hoekzema and Sherman, 1983).

References

MRDS Number A010527

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 1/23/2000