Carbon and sulfur isotope evidence for in situ reduction of sulfate, Nanisivik lead-zinc deposits, Northwest Territories, Baffin Island, Canada

The Nanisivik deposits are Mississippi Valley-type deposits formed through both carbonate replacement and filling of karstlike solutional channelways in the Proterozoic Society Cliffs Formation. The main ore zone consists of banded ore with alternating cm-thick layers of pyrite, sphalerite, and less abundant galena, interlaminated with white sparry dolomite. Similarly laminated ore occurs as replacements that have left tapered fins and totally …