Geologic Setting of Volcanic-Associated Massive Sulfide Deposits in the Kamiskotia Area, Abitibi Subprovince, Canada

摘要

The Upper Archean volcanic succession in the Kamiskotia area (Abitibi greenstone belt, Timmins region) hosts a series of past-producing copper-zinc volcanic-associated massive sulfide (VMS) deposits. All of these occur within a restricted, east-facing stratigraphic interval in the upper part of the Kamiskotia Volcanic Complex. New U-Pb ages for this interval, ranging from 2701.1 ± 1.4 to 2698.6 ± 1.3 Ma, and an age of 2703.1 ± 1.2 Ma from the lower part of the Kamiskotia Volcanic Complex, indicate that the complex is likely part of the Blake River assemblage (2701–2697 Ma) rather than the older Tisdale assemblage (2710–2703 Ma). The Kamiskotia Volcanic Complex consists largely of felsic and mafic lava flows, and VMS mineralization appears to have generally developed at or near the sea floor close to inferred synvolcanic faults.