Unnamed Prospect (ARDF - SI006; southeast of mouth of Stag Bay), Chichagof Mining District (Chicagof Mining District), Hoonah-Angoon Census Area, Alaska, USAi

Regional Level Types
Unnamed Prospect (ARDF - SI006; southeast of mouth of Stag Bay)	- not defined -
Chichagof Mining District (Chicagof Mining District)	Mining District
Hoonah-Angoon Census Area	Census Area
Alaska	State
USA	Country

The site is in West Chichagof-Yakobi Wilderness.
Location: This prospect is on the northeast flank of Mount Hill about a mile south-southeast of the mouth of Stag Bay. The prospect is at an elevation of about 1,500 feet, 0.2 mile north-northeast of the center of sec. 4, T. 46 S., R. 56 E. It is location P-38 of Bittenbender and others (1999), MAS no. 0021140087 (U.S. Bureau of Land Management, 2002), and is included in location 7 of Cobb (1972, 1978). The location is accurate.
Geology: Johnson and Karl (1985) map the rocks in the area of this prospect as Freeburn assemblage, a collage of kilometer-scale, fault-bounded, lozenge-shaped blocks of Cretaceous and Cretaceous(?) metasedimentary and metavolcanic rocks. The prospect is about 0.2 mile west of the Border Ranges Fault, a northwest-striking, steeply-dipping or vertical regional fault that separates Cretaceous or younger rocks on the southwest from Mesozoic or Paleozoic rocks on the northeast. Twenhofel and others (1949) describe this deposit as sheared and altered, fine-grained gabbro or diorite containing magnetite, pyrite, and chalcopyrite. Two trenches expose 55 and 35 feet of mineralized rock that consists of about 60 percent magnetite, about 20 percent each of epidote and quartz, locally abundant pyrite, and up to 2 percent chalcopyrite. Bittenbender and others (1999), citing work by Asbury (1964) and Kimball (1982), describe the prospect as a porphyry deposit containing copper, iron, and tungsten, although tungsten is not reported in the sample analyses that they cite. Their samples contained up to 1.07 percent copper, 20-90 percent magnetite, and a trace of silver.
Workings: Two trenches.
Age: Probably Cretaceous or younger.
Alteration: Unspecified [hydrothermal?] alteration of host rock.

Commodities (Major) - Cu, Fe; (Minor) - Ag
Development Status: None
Deposit Model: Porphyry copper? (Cox and Singer, 1986; model 17).

Other Databases

Link to USGS - Alaska:	SI006

Other Regions, Features and Areas containing this locality

References