Johnston & Degan

Prospect, Inactive

Alternative names

Grubstake & Lost Boys

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale SV
Quadrangle map, 1:63,360-scale C-2
Latitude 59.52
Longitude -150.49
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is located on both sides of the ridge that separates Quartz Bay from Surprise Bay, both of which are in the West Arm of Nuka Bay. This is Cobb's (1972, MF-397) location 25 and MacKevett and Holloway's (1977) location 16. Cobb (1979, OFR 80-87) summarized the relevant references to this prospect under the name Johnson and Degan. This location is accurate within half a mile.

Geologic setting

Geologic description

Cretaceous Valdez Group graywacke host the mineralization of the Johnson and Degan prospect (Richter, 1970). Generally quartz veins are hosted in the graywacke although conglomerates are found in the area. The veins are white quartz containing few percent sulfides, although some exposures show considerable iron-staining. A single sample through a vein at an elevation of 1,000 feet, on the Surprise Bay side of the ridge, assayed 0.98 ounces of gold and 1.0 ounce of silver per ton (Pilgrim, 1933).
Geologic map unit (-150.492098604444, 59.5194199580033)
Mineral deposit model Low-sulfide, Au-quartz vein (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Tertiary; Boden and others (1991) report other veins in the district are about 55 m.y. old.
Alteration of deposit Extensive oxidation staining on surface outcrops. Borden and others (1991) report other veins in the Nuka Bay district show carbonization, sulfidization, sericitization, and silicification of the wall rock adjacent to the veins.

Production and reserves

Workings or exploration Surface trails were laid and trenches were dug in the 1930s. A single sample through a vein at 1000 feet elevation on the Surprise Bay side of the ridge, assayed 0.98 ounces of gold and 1.0 ounce of silver per ton (Pilgrim, 1933).
Indication of production None
Reserve estimates None.

Additional comments

This prospect is within the Kenai Fjords National Park; the area is closed to mineral entry.

References

MRDS Number A010576

References

Pilgrim, E.R., 1933, Nuka Bay district, in Stewart, B. D., Making mining investigations and mine inspection in Alaska, biennium ending March 31, 1933: Alaska Territorial Department of Mines Annual Report 1933B, p. 26-51.
Reporters Jeff A. Huber (Anchorage)
Last report date 2/9/1999