Petrology of the ultramafic and gabbroic rocks of the Brady Glacier nickel-copper deposit, Fairweather Range, southeastern Alaska
Himmelberg GR and Loney RA. 1981. Petrology of the ultramafic and gabbroic rocks of the Brady Glacier nickel-copper deposit, Fairweather Range, southeastern Alaska. U.S. Geological Survey (USGS) Professional Paper. P 1195. US Geological Survey
The basal cumulates of the La Perouse layered gabbro are the host rocks for the Brady Glacier nickel-copper deposit. The cumulates consist of ultramafic and gabbroic rocks interlayered on a scale of centimeters to hundreds of meters. The layers are lenticular and wedge out in all directions. Sulfide minerals are dominately pyrrhotite, pentlandite, and chalcopyrite. There is no relation between disseminated sulfide mineralization and stratigraphic position or rock type, although massive sulfides tend to occur along boundaries between mafic and ultramafic layers. The Brady Glacier cumulates are interpreted to have crystallized from multiple injection of magma batches. Rock and mineral chemical analyses accompany report.--from New Publications of the Geological Survey, August 1981.
- Type
- Published Report
- Authors
- Himmelberg, G; Loney, R
- Date of Issue
- 1981
- Publisher
- US Geological Survey
- Units
- GLBA , KLGO
- Keywords
- Alaska, Brady Glacier, chalcopyrite, Chemical Composition, copper ores, cumulates, disseminated deposits, Economic Geology, Evolution, Exploration, Fairweather Range, gabbros, Gas, Geochemistry, Geology, Glacier Bay National Park and Preserve AK, GLBA, host rocks, Igneous Rocks, Intrusions, La Perouse, layered intrusions, Lithology, Magmas, massive deposits, Metal Ores, Mineral, Mining, Monographic, nickel ores, Oil, ore minerals, pentlandite, Petrology, pyrrhotite, Report, Serial, Southeastern Alaska, Sulfides, ultramafics, United States, USGS, Western U.S.