The Isotopic Composition of Strontium in Fossils from the Kendrick Shale, Kentucky

Author Institution: Department of Geology and Mineralogy, The Ohio State UniversityNine analyses of the isotopic composition of strontium in the carbonate shells of marine fossils from the Kendrick Shale (Lower Pennsylvanian) of Kentucky indicate an average 87Sr/86Sr ratio of 0.7086^O.OOOSS at the 95 percent confidence limit. This value is in satisfactory agreement with previous measurements by Peterman et al. (1970) and confirms that strontium in the oceans during Early Pennsylvanian time was anomalously enriched in radiogenic 87Sr, compared to that in earlier and later periods. The isotopic composition of strontium in skeletal clacium carbonate of cephalopods, gastropods, and brachiopods from the Kendrick Shale appears to be the same in spite of the different feeding habits of these animals