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Geochemistry of the Chattanooga shale, Dekalb County, central Tennessee.

January 1, 1983

This Upper Devonian shale is of interest because of its unusual enrichment in trace elements, especially U; a new chemical analysis for major, minor and trace elements is presented. Stable isotopes of carbon (organic) show delta 13C approx -29per mille and for total sulphur show -21 to -27per mille delta 34S. The organic matter was found to range from dominantly marine (Dowelltown member) to dominantly terrestrial (Gassaway member) by extraction-column chromatography-GS and also by pyrolysis-GS of kerogen. Trace elements U, Mo, Co, Zn, Cu, Ni, V, As and Hg are enriched in the organic- and sulphide-rich units. This enrichment can be related to a euxinic depositional environment, to a very slow sedimentation rate (approx 2 mm/1000 years), to the type of organic matter that varied from mainly marine to terrestrial, and to the source of the metals, which shows abundance variations that originated, at least in part, from volcanic ash layers.-R.S.M.

Citation Information

Publication Year 1983
Title Geochemistry of the Chattanooga shale, Dekalb County, central Tennessee.
Authors J.S. Leventhal, Paul H. Briggs, J.W. Baker
Publication Type Article
Publication Subtype Journal Article
Series Title Southeastern Geology
Series Number
Index ID 70011159
Record Source USGS Publications Warehouse
USGS Organization