Alameda

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu; Zn
Ore minerals chalcopyrite; pyrrhotite; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale A-3
Latitude 60.0019
Longitude -147.8661
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is located in the SW1/4 section 14, T. 2 S., R. 9 E., of the Seward Meridian. It is near sea level along the shoreline, 0.7 mile southeast of Reynolds Peak, Latouche Island. This is location 267 of Tysdal (1978 [MF-880-A]) and location S-6 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The occurrence consists of two zones: a mineralized graywacke and a shear zone. The mineralized graywacke zone contains small bunches and stringers of chalcopyrite scattered though it. The zone varies from 4 to 40 feet wide and is traceable for some distance (Johnson, 1916 [B 662-C, p. 210-211]). North of the mineralized graywacke zone a 4-foot-wide shear zone is exposed for a short distance. This zone contains chalcopyrite, pyrrhotite, and sphalerite. Both zones are subparallel to the northeasterly strike and westerly dip of the host rock, which is graywacke of the Orca Group of early Tertiary age (Nelson and others, 1985).
Geologic map unit (-147.868098018821, 60.0012418335975)
Mineral deposit model Besshi massive sulfide (Cox and Singer, 1986; model 24b)
Mineral deposit model number 24b
Age of mineralization Tertiary or younger; the mineralization is in rocks of the Orca Group of Tertiary age.

Production and reserves

Indication of production None

References