Hydropit Occurrence, Ketchikan Gateway Borough, Alaska, USAi

Regional Level Types
Hydropit Occurrence	Occurrence
Ketchikan Gateway Borough	Borough
Alaska	State
USA	Country

Location: Location known exactly and easily found; deposit exposed in a rock quarry adjacent to a logging road on central Zarembo Island. Site in the SW1/4, section 27, T. 63 S., R. 80 E. Locality 63 of Grybeck, Berg, and Karl (1984).
Geology: The country rock is a Tertiary alkalic granite well exposed in a rock quarry; the intrusive is cut by sperulitic felsic dikes which are in turn cut by andesite dikes (Brew, 1997 [OF 97-156-E]). The mineralization consists of quartz veinlets and lenses an inch or so thick in an altered shear zone about 4 feet wide that cuts the granite. The quartz vein material contains a few percent of ore minerals including chalcopyrite, bornite, galena, sphalerite, arsenopyrite, and magnetite. On analysis, selected high-grade grab sample show major Pb, Zn, and Cu consistent with the hand-specimen mineralogy, less than 0.005 ppm Au, up to 50 ppm Ag, up to 15 ppm Sn, and up to 3 ppm W. The exposure of the vein is small but could indicate more vein-type mineralization in the area.
Workings: Occurrence first found by the USGS in the late 70's in a quarry excavated for road metal. To 1996, no obvious signs or published descriptions of other work at the site.
Age: Tertiary or younger.
Production: None
Reserves: None

Commodities (Major) - Cu, Pb, Zn
Development Status: None
Deposit Model: Polymetallic vein along shear zone (Cox and Singer, 1986; model 22c)

Other Databases

Link to USGS - Alaska:	PE061

Other Regions, Features and Areas containing this locality

References