PG West Occurrence, Tok Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
PG West Occurrence	Occurrence
Tok Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Unpublished data cited is available for viewing by contacting Grayd Resources Inc. in Vancouver, B. C., Canada (www.grayd.com), or Northern Associates Inc. in Fairbanks, Alaska.
Location: The PG West occurrence is 0.2 mile southwest of peak 7630 and in the NW1/4 section 16, T. 18 N., R. 5 E., Copper River Meridian. The location is accurate.
Geology: The PG West occurrence is a massive sulfide deposit with chalcopyrite, galena, pyrite, and sphalerite in a quartz-ankerite gangue. The deposit is in altered and brecciated quartz sericite schist and carbonaceous schist. Fine to very coarse grained quartz arenite and quartzite units underlie the occurrence, which is above a mafic intrusive body below the PG West occurrence. A gray siltstone composed of quartz, sericite, and graphite forms the hanging wall of the deposit; the overlying rocks consist of chloritic phyllites and intermediate to felsic schists thought to have originally been volcanic sediments and rhyolite tuffs (J. K. Muntzert and others, unpublished Resource Associates of Alaska Inc. report, 1977). The occurrence was originally described as a volcanogenic massive sulfide deposit. Subsequent examination by American Copper and Nickel in 1994 indicated that the sulfides may be related to skarn developed beside a mafic intrusive (W. Shalosky, written communication, 1994). Resource Associates of Alaska Inc. drilled one core hole in 1977 after finding pyritic massive sulfides in talus. Some pyrite was was intersected in a 1-foot interval in the core; it contained 0.1 percent copper, 0.8 percent lead, 1.5 percent zinc, 27.8 parts per million (ppm) silver, and 0.1 ppm gold (E. Hunter, unpublished data, 1998).
Workings: Surface sampling and mapping that found the massive sulfide float led to Resource Associates of Alaska Inc. drilling one core hole in 1977.
Age: The enclosing Drum unit has been dated at the Devonian-Mississippian boundary on the basis of one SHRIMP U-Pb zircon age of 359+/- 6 Ma determined at the DD South deposit (MH325) (Dashevsky and others, 2003).
Alteration: Strong enveloping pyrite; ankerite; regional carbonate alteration (Lange and others, 1993).

Commodities (Major) - Pb, Zn; (Minor) - Ag, Au, Cu
Development Status: None
Deposit Model: Kuroko massive sulfide (Cox and Singer, 1986; model

Other Databases

Link to USGS - Alaska:	MH258

Other Regions, Features and Areas containing this locality

References