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Extreme 34S depletions in ZnS at the Mike gold deposit, Carlin Trend, Nevada: Evidence for bacteriogenic supergene sphalerite

January 1, 2003

We identified submicrometer-sized framboidal sphalerite (ZnS) below the base of supergene oxidation in a Carlin-type gold deposit of Eocene age in Nevada, United States, where the framboidal sphalerite forms a blanket-like body containing >400,000 metric tons of zinc. Framboidal sphalerite <0.1 ??m in diameter, formed in the early Miocene, ranges from <0.1 to 0.35 mol% FeS; the ??34S values range from -25??? to -70???, the lowest values measured in a marine or terrestrial environment. These S isotope data demonstrate the involvement of sulfate-reducing bacteria and provide the first documentation that sphalerite can form significant supergene sulfide-enrichment blankets.

Citation Information

Publication Year 2003
Title Extreme 34S depletions in ZnS at the Mike gold deposit, Carlin Trend, Nevada: Evidence for bacteriogenic supergene sphalerite
DOI 10.1130/G19831.1
Authors T.M. Bawden, M.T. Einaudi, B.C. Bostick, A. Meibom, J. Wooden, J.W. Norby, M.J.T. Orobona, C. P. Chamberlain
Publication Type Article
Publication Subtype Journal Article
Series Title Geology
Series Number
Index ID 70025582
Record Source USGS Publications Warehouse
USGS Organization