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The stable isotope geochemistry of acid sulfate alteration

January 1, 1992

Acid sulfate wall-rock alteration, characterized by the assemblage alunite + kaolinite + quartz ?? pyrite, results from base leaching by fluids concentrated in H2SO4. Requisite amounts of H2SO4 can be generated by different mechanisms in three principal geologic environments: 1) by atmospheric oxidation of sulfides in the supergene environment, 2) by atmospheric oxidation at the water table in the steam-heated environment of H2S released by deeper, boiling fluids, and 3) by the disproportionation of magmatic SO2 to H2S and H2SO4 during condensation of a magmatic vapor plume at intermediate depths in magmatic hydrothermal environments in silicic and andesitic volcanic terranes. In addition, coarse vein alunite may form in a magmatic steam environment. -from Authors

Citation Information

Publication Year 1992
Title The stable isotope geochemistry of acid sulfate alteration
Authors R. O. Rye, P. M. Bethke, M.D. Wasserman
Publication Type Article
Publication Subtype Journal Article
Series Title Economic Geology
Index ID 70016673
Record Source USGS Publications Warehouse