Unnamed (Kipchuk River area) (ARDF #BH026) Ag, Cu, Hg, Pb, Zn

Occurrence, Inactive

Quadrangle map, 1:250,000-scale	BH
Quadrangle map, 1:63,360-scale	D-1
Latitude	60.82
Longitude	-159.29
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is at an elevation of about 2100 feet, about 3.4 miles north of the 'elbow' of Kipchuck River. The map site is in the SW1/4 of sec. 31, T. 9 N., R. 56 W., of the Seward Meridian. The site corresponds to is locality 7 of Frost (1990, fig. 1). The location is probably accurate within about 1 mile.

Geologic description At this occurrence, water-lain tuff near the base of the Kipchuk volcanic field is partially to completely replaced by quartz and tourmaline (Frost, 1990, p. C4). The altered rocks weather as bright red, vegetation-free areas. Rock samples contain up to 70 ppm Ag, 1,500 ppm As, greater than 2,000 ppm B, 1,000 ppm Cu, 2,000 ppm Pb, 1,500 ppm Sb, 100 ppm Sn, greater than 20,000 ppm Zn, and greater than 36 ppm Hg (Frost, 1990; Frost and others, 1992). Gold was detected at less than 0.05 ppm in one sample. The Kipchuk volcanic field is a large area of Upper Cretaceous andesite, basalt, tuff, and local rhyolite in the uplands between the Kipchuk and Aniak River drainages (Box and others, 1993).
Geologic map unit	(-159.292276879929, 60.8192750166271)
Mineral deposit model	Polymetallic veins (Cox and Singer, 1986; model 22c).
Mineral deposit model number	22c
Age of mineralization	Post-Late Cretaceous. Quartz and tourmaline replace volcanic rocks of the Kipchuk volcanic field that locally yield 69 to 71 Ma K/Ar ages (Box and others, 1993).
Alteration of deposit	Quartz and tourmaline replacement, oxidation.

Workings or exploration	Reconnaissance surface observation and geochemical sampling has occurred at this site.
Indication of production	None