Main commodities | Ni |
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Other commodities | Au |
Ore minerals | pyrite; pyrrhotite |
Quadrangle map, 1:250,000-scale | SI |
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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 descriptionLoney 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) |
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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 |
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Additional commentsThe prospect is in West Chichagof-Yakobi Wilderness. |
ReferencesBittenbender, 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]
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Reporters | H.C. Berg (U.S. Geological Survey) |
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Last report date | 10/16/2004 |