Unnamed (east of upper Tunulik River)

Prospect, Undetermined

Commodities and mineralogy

Main commodities Au; Cu
Ore minerals chalcopyrite; gold
Gangue minerals orthoclase; quartz

Geographic location

Quadrangle map, 1:250,000-scale GO
Quadrangle map, 1:63,360-scale B-7
Latitude 59.253
Longitude -161.5
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of about 1,450 feet on the southwest flank of a ridge, about 0.6 mile east of upper Tunalik River. The map site is in the west 1/2 of section 1, T 11 S, R 73 W, of the Seward Meridian. The location is probably accurate within 1/4 mile. This is locality 4 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 Surface observations completed for Calista Corporation (unpublished data) identified diorite or gabbro with podlike segregations (?) containing 1 to 2 percent chalcopyrite (Fechner, 1988, p. 63). A local quartz-orthoclase vein, 2 inches wide, assayed 3 ppm Au and 3,000 ppm As. The stream sediment from a small creek flowing southwest to the Tunulik River from the prospect contained 4.1 ppm Au; pan concentrate from this location contained gold flakes.
Geologic map unit (-161.502233864651, 59.2522239098421)
Mineral deposit model Vein and segregations? in mafic rocks.
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).

Production and reserves

Workings or exploration Reconnaissance surface observations and sampling have been completed in the prospect area (Calista Corporation, unpublished data).
Indication of production None