Prospect, Undetermined

Commodities and mineralogy

Main commodities Ag; Au; Cu
Ore minerals arsenopyrite; chalcopyrite; pyrite; pyrrhotite
Gangue minerals biotite; chlorite; quartz

Geographic location

Quadrangle map, 1:250,000-scale GO
Quadrangle map, 1:63,360-scale B-7
Latitude 59.27
Longitude -161.49
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the divide between the headwaters of an unnamed north tributary to the Tunulik River and the Barnum Creek drainage. The prospect is in a saddle at an elevation of about 1,500 feet and about 1 mile west of a 2,298-foot summit of Ikuktlitlig Mountain It is locality 3 of Kilburn and others (1993).

Geologic setting

Geologic description

A composite mafic to felsic pluton intrudes Paleozoic to Mesozoic sedimentary and volcanic rocks in this area (Hoare and Coonrad, 1978). Surface observations completed for Calista Corporation (unpublished data), identified peridotite, diorite, granodiorite, and quartz monzonite in the intrusive complex. A variably silicified, chloritized, and biotite-altered, 800-foot-wide fractured zone in diorite contains chalcopyrite, arsenopyrite, pyrrhotite, and pyrite (Fechner, 1988, 61). Rock samples from the prospect contain up to 2.4 percent Cu, 25.2 ppm Ag, 0.16 ounce of gold per ton, and 0.99 percent As.
Geologic map unit (-161.492234284801, 59.2692244189581)
Mineral deposit model Sulfide-bearing shear zone in diorite
Age of mineralization Not known. The age of the host intrusive rock is probably Jurassic or Late Cretaceous/Early Tertiary, the age of other intrusive rocks in the region (Hoare and Coonrad, 1978).
Alteration of deposit Silicification, chloritization, and biotite replacement (?).

Production and reserves

Workings or exploration Reconnaissance surface observations and sampling have been completed in the prospect area.
Indication of production None