Unnamed Occurrence (ARDF - BR003; base of Pink Bluff), Black Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - BR003; base of Pink Bluff)	- not defined -
Black Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is an outcrop at the base of Pink Bluff about 50 feet from the south bank of the Salmon Fork of Black River. It is about 0.2 mile downstream of the mouth of Runt Creek, in the SW1/4SW1/4 section 27 (almost on boundary with section 28), T. 19 N., R. 29 E., of the Fairbanks Meridian. The location is accurate within several hundred feet.
Geology: Sphalerite and galena occur in a gossan zone about 60 feet long and 2 feet wide in mottled pink and gray dolomite (K.H. Clautice, unpublished field data, 1992). A grab sample of massive galena veined with calcite assays 80.69 percent lead, and a sample of dense, brick-red gossan contains 18,557 ppm zinc (U.S. Bureau of Mines, 1995). Lead isotope ratios (Clough and others, 1993) are similar to those of Lower Cambrian (about 520 Ma) 'Older Carbonate' -hosted zinc-lead deposits in western Canada (Godwin and others, 1982). Dover (1994) maps the dolomite as part of the Lower Cambrian and Proterozoic, Tindir Group, which consists predominantly of carbonate, quartzite, argillite, and subordinate volcanic rocks. Stromatolites resembling those of the Pack Formation of the Tindir Group occur in the vicinity (Doyon Limited, 1977).
Age: Lead isotope ratios (Clough and others, 1993) are similar to those of Lower Cambrian (about 520 Ma) 'Older Carbonate' -hosted zinc-lead deposits in western Canada (Godwin and others, 1982).
Alteration: Iron oxides.

Commodities (Major) - Pb, Zn
Development Status: None
Deposit Model: Southeast Missouri Pb-Zn (Cox and Singer, 1986; model 32a)

Other Databases

Link to USGS - Alaska:	BR003

Other Regions, Features and Areas containing this locality

References