Unnamed Occurrence (ARDF - PE116; on Shrubby Island), Kupreanof Mining District, Prince of Wales-Hyder Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - PE116; on Shrubby Island)	Occurrence
Kupreanof Mining District	Mining District
Prince of Wales-Hyder Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is in a borrow pit about 0.8 mile east-southeast of the northwest tip of Shrubby Island; the pit is shown on the 1:63,360-scale topographic map. It is in the NE1/4, section 14, T. 65 S., R. 80 E.
Geology: Still and others (2002) visited the borrow pits on Shubby Island and examined the road cuts on the logging roads of the island to try to discover the source of the strongly anomalous stream sediment samples that were reported earlier by the U.S. Geological Survey. They discovered mineralization in a borrow pit on the northwest end of the island. The mineralization consists of pods of sulfides in blocky, dark gray to white limestone of the Heceta Limestone (Karl and others, 1999). The pods are up to 2 feet long, 1 foot thick, and are mainly of fine grained pyrite with sphalerite and minor galena. The sulfides also occur in a network of thin veinlets that cut the limestone in an area about 10 feet in diameter. A 0.5-foot sample across one of the pods contained 8.1 percent zinc, and 3,646 parts per million (ppm) lead. A sample across 2.1 feet of the sulfide veinlets in the limestone contained 1.3 percent zinc and 476 ppm lead. The highest gold value in the samples Still and others (2002) collected was 19 parts per billion; the highest silver value was 2.6 ppm.
Workings: Only sampling by government engineers and geologists.
Age: Silurian or younger based on the age of the Heceta Limestone that hosts the mineralization.

Commodities (Major) - Pb, Zn; (Minor) - Ag, Au
Development Status: None
Deposit Model: Pb-Zn sulfide pods in limestone.

Other Databases

Link to USGS - Alaska:	PE116

Other Regions, Features and Areas containing this locality

References