Unnamed (west of Togiak Lake)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite; malachite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale GO
Quadrangle map, 1:63,360-scale C-2
Latitude 59.659
Longitude -159.672
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is in the uplands along the west side of Togiak Lake. The map site is at an elevation of about 2,250 feet on a saddle 1/2 mile north-northwest of a local summit with an elevation of 3,547 feet. The location is probably accurate within 1/2 mile. It is included in Hoare and Cobb (1977) under the name 'Togiak Lake'.

Geologic setting

Geologic description

The upland between Togiak Lake and Kemuk River is cored by a large, Cretaceous(?) granitic pluton with a well-developed hornfels aureole (Hoare and Coonrad, 1978). Many stream-sediment samples in this area contain anomalous amounts of copper and manganese (Cieutat and others, 1988). At this location, along the east contact of the granitic pluton, chalcopyrite and malachite occur in a small quartz vein cutting quartz diorite (Hoare and Cobb, 1977, p. 49).
Geologic map unit (-159.67422304304, 59.658249063187)
Mineral deposit model Vein
Age of mineralization Probably Late Cretaceous. Mineralization is probably related to the granitic pluton in the area, which is part of a regionally extensive Upper Cretaceous and Lower Tertiary plutonic suite. K/Ar ages for granitic samples from near this locality are 63.7 +/- 2 Ma on biotite and 67.5 +/-3 Ma on hornblende (Hoare and Coonrad, 1978).
Alteration of deposit Silicification.

Production and reserves

Workings or exploration Reconnaissance stream-sediment sampling has been completed in the area.
Indication of production None

References