|Quadrangle map, 1:250,000-scale||SI|
|Quadrangle map, 1:63,360-scale||D-7|
|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.|
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).|
|Indication of production||None|
Additional commentsThe prospect is in West Chichagof-Yakobi Wilderness.
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.
Loney, R.A., Brew, D.A., Muffler, L.J.P., and Pomeroy, J.S., 1975, Reconnaissance geology of Chichagof, Baranof, and Kruzof Islands, southeastern Alaska: U.S. Geological Survey Professional Paper 792, 105 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|