Unnamed Occurrence (ARDF - SK052; on headwater tributary to Porcupine Creek), Haines, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - SK052; on headwater tributary to Porcupine Creek)	- not defined -
Haines	City Borough
Alaska	State
USA	Country

Location: This occurrence is at an elevation of approximately 3,500 feet on the east side of an unnamed headwater tributary to Porcupine Creek near the divide to Cottonwood Creek. It is in the the SW1/4, section 23, T. 29 S., R. 54 E. of the Copper River Meridian. It is shown as location 146 by Still and others (1987) and as site R by Gilbert and Redman (1989) who informally referred to it as the 'Porcupine Roof Pendant'.
Geology: According to Still and others (1991), this occurrence is a mineralized, 400 foot by 1,000 foot, roof pendant surrounded by diorite. The pendant consists of metamorphosed slate and limestone that form bands of garnet and diopside at some locations. Samples from the pendant contained up to 0.068 ppm gold, 1.1 ppm silver, 192 ppm zinc, and 230 ppm copper (Gilbert and others, 1991), and a sample of gossan rubble with 20% pyrite collected 500 feet below the pendant contained 6.33 ppm gold, 18.2 ppm silver, and 515 ppm copper (Still and others, 1991). The metamorphosed slate and limestone are of probable Paleozoic age (MacKevett and others, 1974). The bands of garnet and diopside and the mineralization are probably due to to contact metasomatism by the surrounding Cretaceous diorite (MacKevett and others, 1974).
Age: Probably Cretaceous or younger based on the age of the surrounding diorite (MacKevett and others, 1974).
Alteration: Development of calc-silicate minerals.

Commodities (Major) - Ag, Au; (Minor) - Cu
Development Status: None
Deposit Model: Based on limited information, this is probably a skarn related occurrence (Cox

Other Databases

Link to USGS - Alaska:	SK052

Other Regions, Features and Areas containing this locality

References