Isotopic Study of a Siderite Concretion, Tuscarawas County, Ohio
نویسنده
چکیده
A carbonate concretion from the shale bed overlying the No. 5 coal of Pennsylvanian age in Tuscarawas County is composed of siderite and contains pyrite, barite, sphalerite and traces of calcite in its interior and in fractures. The siderite has 8 C = + 0.65%o, Sr=289 ppm and Sr/Sr=0.7110±0.0009These results indicate that the siderite was deposited from brackish water in the pore spaces of the sediment and discredit the hypothesis that the carbonate ions originated by oxidation of peat or organic material. The barite has 8 S=— 4.6%o, indicating that it was not precipitated from sea water. Pyrite and sphalerite have 8 S= — 10.8%o and — 4.6%o, respectively, and were not deposited in isotopic equilibrium with each other. The sulfur in all three minerals is enriched in 3 l6S as a result of bacterial reduction of sulfate to sulfide. OHIO J. SCI. 82(1): 52, 1982
منابع مشابه
Early Diagenetic Calcareous Coal Balls and Roof Shale Concretions from the Pennsylvanian (Allegheny Series)
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