Unnamed Occurrences (ARDF - PA032; near Mount Muravief), Chichagof Mining District (Chicagof Mining District), Sitka, Alaska, USAi

Regional Level Types
Unnamed Occurrences (ARDF - PA032; near Mount Muravief)	- not defined -
Chichagof Mining District (Chicagof Mining District)	Mining District
Sitka	City Borough
Alaska	State
USA	Country

These occurrences are now in the South Baranof Wilderness Area which is closed to mineral exploration and mining.
Location: This deposit consists of several occurrences that are strung out in an arc that extends northwest for about a mile. The center of these occurrences is about 0.4 mile west of Mount Muravief and about 0.5 mile east-southeast of the center of section 3, T. 62 S., R. 68 E. The location is accurate and figures 8 and 9 of Bittenbender and others (1999) show the occurrences in detail.
Geology: These occurrences were first identified in the 1930's but there was little systematic work on them until the late 1990's when Bittenbender and others (1999) examined them. The rocks in the vicinity are graywacke and argillite with minor greenstone and volcanic breccia. Locally bedding can be identified but most of the rocks are metamorphosed and often tightly folded and foliated. The rocks generally strike northwest and dip steeply southwest. Loney and others (1975) maps them as part of the Sitka Graywacke of Cretaceous age. The mineralization is associated with folded layers of greenstone up to 100 feet thick that extend for up to 1,000 feet along strike. Three such occurrence occur along an arcuate band that extends for about 6,000 feet (Bittenbender and others, 1999, figs. 8 and 9). The mineralization consists of chalcopyrite and pyrrhotite that occur both disseminated in the graywacke and greenstone and in massive lenses up to 3 feet thick and 10 feet long. The lenses are often associated with volcanic breccia. Malachite staining is common. Thirty-two samples were collected by Bittenbender and others (1999). They contained up to 6.33 percent copper, 600 parts per billion gold, 14.5 parts per million (ppm) silver, and 2,200 ppm zinc. A sample across 18 feet of mineralization on the west ridge of Mount Muravief contained 1.63 percent copper, 3.6 ppm silver, and 500 ppm zinc. Work by the Bureau of Mines in the late 1960's (Gnagy, 1969) identified bands of chalcocite in samples collected in this vicinity; these samples may come from other as-yet-unidentified mineralization.
Workings: These occurrences were discovered in the 1930's but apparently little work was done on them until the late 1990's when they were mapped in detail by the U.S. Bureau of Land Management.
Age: Cretaceous or younger based on the age of the host rock.
Reserves: None.

Commodities (Major) - Ag, Au, Cu, Zn
Development Status: None

Other Databases

Link to USGS - Alaska:	PA032

Other Regions, Features and Areas containing this locality

References