Commodities
PrimarySilver, Copper
Commodity typeM
Deposit
Model53: Porphyry Cu105: Epithermal vein, generic
Materials
Ore mineralsChalcopyrite, Pyrite
GangueMagnetite
Geology
AlterationAlteration of the porphyry consists of chloritized mafic minerals, chalky feldspar, and minor disseminated pyrite. In zones outward from the contact with the porphyry the Unalaska Formation displays pervasive sericitic alteration and contains minor quartz veinlets and pyrite. Peripheral to this the rocks contain sericite and pyrite in fractures which grades to pervasively developed chlorite (propylitic alteration) and pyrite limited to fractures; and finally pervasive epidote and disseminated pyrite. Christie (1974) reports partial leaching, complete in the breccia, however the leached phase is not identified.
Economic & production
Development statusOccurrence
Identification
Deposit ID10003272
MRDS IDA106015
RegionNA
Data scoreD
Coordinates53.70243, -166.98572
References
Drewes, Harold, Fraser, G.D., Snyder, G.L., and Barnett, H.F., Jr., 1961, Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska: U.S. Geological Survey Bulletin 1028-S, p. 583-676.Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps. (Report held by the Aleut Corporation, Anchorage, Alaska.)