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U.S. Department of Energy
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Upwelling in Cretaceous western interior seaway

Conference ·
OSTI ID:6131809

The Sharon Springs Member of the Pierre Shale, usually described as a stagnant-basin deposit, shares more features in common with upwelling zones than with stratified stagnant basins. Specifically, the overall facies distribution of the Sharon Springs includes a basin-ward zone of laminated, highly organic-rich strata bounded on the west by phosphate, which is, in turn, bounded at the western shoreline by glauconitic sandstone. The same facies distribution might be expected on the eastern shoreline, but the Sharon Springs is truncated there by erosion. The organic matter in the Sharon Springs is almost entirely contained in fecal pellets and is predominantly marine in origin. Organic carbon accumulation rates are comparable to those of upwelling zones. Finally, the Sharon Springs is noted for high concentrations of bones of marine reptiles. These bones occur in a band that may mark the zone of highest biologic productivity.

OSTI ID:
6131809
Report Number(s):
CONF-880301-
Country of Publication:
United States
Language:
English