Phonograph

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Ni
Other commodities Au
Ore minerals pyrite; pyrrhotite

Geographic location

Quadrangle map, 1:250,000-scale SI
Quadrangle map, 1:63,360-scale D-7
Latitude 57.9163
Longitude -136.0713
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Phonograph prospect is at an elevation of about 800 feet, on the east valley wall of lower Phonograph Creek. The prospect is 0.5 mile north-northeast of the center of sec. 6, T. 46 S., R. 58 E. It is location P-18 of Bittenbender and others (1999) and MAS no. 0021140092 (U.S. Bureau of Land Management, 2002). The location is accurate within about 0.2 mile.

Geologic setting

Geologic description

Loney and others (1975) map the rocks in the area of this prospect as Paleozoic, sedimentary and volcanic rocks that are intruded by and are roof pendants in a Cretaceous quartz diorite batholith. The Paleozoic rocks have been thermally metamorphosed to hornfels, granofels, marble, schist, and amphibolite. The rocks are cut by numerous high-angle faults of diverse strike.
Bittenbender and others (1999) describe the prospect as a magmatic segregation deposit in pyroxenite. A sample contained 0.31 percent nickel and a trace of gold. They do not specify the ore minerals, but other magmatic segregation deposits on northwest Chichagof Island (for example, SI001) contain at least pyrite and pyrrhotite.
Geologic map unit (-136.073125056863, 57.9159200526902)
Mineral deposit model Magmatic segregation.
Age of mineralization Assuming Bittenbender and others' interpretation that this a magmatic segregation deposit, it is cogenetic with the pyroxenite host rock, which is probably part of a Cretaceous batholith (Loney and others, 1975).

Production and reserves

Indication of production None

Additional comments

The prospect is in West Chichagof-Yakobi Wilderness.

References

References

Bittenbender, P., Still, J.C., Maas, K., and McDonald, M., Jr., 1999, Mineral resources of the Chichagof and Baranof Islands area, southeast Alaska: Bureau of Land Management, BLM-Alaska Technical Report 19, 222 p.
U.S. Bureau of Land Management, 2002, Alaska mineral locations database report (Sitka quadrangle), July 2, 2002, 205 p. [http://imcg.wr.usgs.gov/dem.html]
Reporters H.C. Berg (U.S. Geological Survey)
Last report date 10/16/2004