Title

Early diagenesis of sulfur in the sediments of lakes that receive acid mine drainage

Document Type

Article

Publication Date

1-1-1991

Abstract

Abstract: Fifteen final-cut strip mine lakes, located throughout the Western Interior, Eastern Interior, and Appalachian Coal Basins in the U.S.A., were selected to represent a wide variety of values for the variables lake-water pH, alkalinity, SO4 and Fe concentrations, sediment organic matter content, overburden lithology, and lake age. Lake-water, porewater and sediment samples were collected for geochemical analysis. Sequential digestion of sediment samples was used to determine the amount of the inorganic S phases (elemental S, metal monosulfide, metal disulfide, and total) present in the sediment. Authigenic inorganic reduced S minerals were found in the sediments of all 15 lakes that receive acid mine drainage from groundwater input. Authigenic FeS2 was the largest fraction in most of the lake sediments, but elemental S was larger in some. The amount of C-bonded S, determined by difference, ranged widely but was nearly always less abundant than the inorganic phases. Correlations of the nature and amount of authigenic reduced S minerals to the SO4 and Fe concentrations in porewater, the organic matter content of the lake sediments, and lake age were tested. The formation of SO4-reduction end products was not limited by Fe or SO4 availability. The amounts of reduced S in the sediments correlated with the amount of organic matter in the sediment, indicating that the authigenic mineral formation process is organic-matter limited in these Fe- and SO4-rich environments. Lake age, which represents a complex function of the diminishing acid-mine-drainage load derived from weathered spoil piles and the generation of alkalinity by biogeochemical reactions in the lake sediments, was a good predictor of the amounts of reduced S mineral in the sediment regardless of geological setting. © 1991 Pergamon Press.

Publication Source (Journal or Book title)

Applied Geochemistry

First Page

213

Last Page

224

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