Bidirectional sulfate diffusion in saline-lake sediments: Evidence from Devils Lake, northeast North Dakota

S.C. Komor

doi:10.1130/0091-7613(1992)020<0319:bsdisl>2.3.co;2

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Bidirectional sulfate diffusion in saline-lake sediments: Evidence from Devils Lake, northeast North Dakota

S.C. Komor

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Abstract

Chemical and isotopic gradients in pore water in Devils Lake indicate that maximum rates of sulfate reduction occur between 1 and 3 cm depth in the bottom sediments. Dissolved sulfate diffuses into the sulfate-reduction zone upward from deeply buried saline pore water at an average rate of 1.4 x 10 -5 μmol ⋅ cm -2 ⋅ s -1 , and downward from the overlying water column at an average rate of 2.4 x 10 -5 μmol ⋅ cm -2 ⋅ s -1 . The result is a bidirectional flux of sulfate into the sulfate-reduction zone. Upward-diffusing sulfate provides a ready supply of electron acceptors for sulfate-reducing bacteria even at fairly great depths in the sediments. The abundance of electron acceptors enables sulfate-reducing bacteria to outcompete methanogenic bacteria for organic material and thereby suppress methane production. Suppression of methanogenesis may be widespread in sulfate-rich lakes and wetlands and may limit methane fluxes from these water bodies to the atmosphere.

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Geology Article

Source-reported bounding extent: 47.83804887261066° to 48.244796538712365° latitude; -99.35760498046875° to -98.51852416992186° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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BibTeX RIS

S.C. Komor. 1992. Bidirectional sulfate diffusion in saline-lake sediments: Evidence from Devils Lake, northeast North Dakota. https://doi.org/10.1130/0091-7613(1992)020%3C0319%3Absdisl%3E2.3.co%3B2

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