Unnamed (near Jarvis Island)

Occurrence, Undetermined

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite; pyrite; pyrrhotite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale CR
Quadrangle map, 1:63,360-scale C-2
Latitude 55.50308
Longitude -132.55464
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is about 0.3 mile southwest of the center of Jarvis Island in the NW1/4 section 31, T. 73 S., R. 85 E. The location is accurate.

Geologic setting

Geologic description

Sainsbury (1961) identified chalcopyrite in recrystallized limestone, and chalcopyrite, pyrrhotite, and pyrite in quartz veinlets in skarn at the contact of a quartz diorite body that intrudes the Ordovician and Silurian Descon Formation. Sainsbury mapped the intrusion as Cretaceous but it probably is part of the large pluton to the northwest across Twelvemile Arm, which has recently been dated as Devonian (S.M. Karl, oral communication, 2003). Maas and others (1991) took two samples of skarn that contained negligible metal values.
Geologic map unit (-132.556303538945, 55.5027189623232)
Mineral deposit model Skarn with quartz veinlets.
Age of mineralization Probably related to the contact zone of a Devonian (?) granitic intrusion.
Alteration of deposit Skarn developed at contact of a Devonian (?) granitic intrusion.

Production and reserves

Workings or exploration Only limited surface sampling by government geologists.
Indication of production None

Additional comments

This occurrence is on land that has been conveyed to the Sealaska Corporation, who hold the surface and subsurface rights, or the land is under application for transfer to them.

References