A paleoecologic evaluation of depositional models for upper Ordovician Kope and Fairview formations
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Date
1973
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Publisher
The Ohio State University
Abstract
A study of the trends in abundance of certain fossil groups from the medium-bedded limy shales of the Upper Ordovician Kope Formation to the thin- to medium-bedded shaly limestones of the Fairview Formation near Ripley, Ohio, was made, and the results are combined with lithological considerations to interpret changes in the environment of deposition of the area. To account for an upward decrease in shale percentage, decrease in bed thickness, increase in biomass and diversity, and increase of forms that require a hard substrate for attachment, the following model is proposed: In the broad, shallow shelf area in which the Kope and Fairview Formations were deposited, there was a gradual shallowing of the water, accompanied by a slight increase in mechanical energy and a slight decrease in the influx of terrigenous sediment.