Late Ordovician Paleontology, Sedimentology
and Stratigraphy in Ohio, Indiana and Kentucky
A Keck Geology Consortium Project
June 19 - July 16, 1999
Hardgrounds are synsedimentarily lithified carbonate seafloors that became hardened in situ by the precipitation of a carbonate cement in their primary pore space (Wilson and Palmer, 1992). The solidfication of the sea floor gives opportunity for boring and encrusting fauna to colonize. Occasionally these hardground communities are buried quickly by fine grained sediments and are preserved in extraordinary detail. These preserved hardgrounds provide detailed glimpses into the structure of the original community (Wilson and Palmer, 1992).
A new Upper Ordovician hardground was discovered in a roadcut on Highway 3071 located west of Maysville, Kentucky. It was found near the comformable boundary of the Fairview Formation and the Grant Lake Formation of the Cincinnatian Series. Preserved on the hardground are large encrusting bryozoans, which are bored in places, and a large community of edrioasteroids. The rare edrioasteroids and large bryozoans provide a unique opportunity to study a seldom seen paleocommunity.
With what type of depositional environment was the hardground associated?
What are the species of fossils present on the hardground? What type of
animal or animals bored into the bryozoans and hardground? What are the
relationships, if any, among the different species of animals? Why did the
creatures living on the hardground die? How does this hardground relate to
others found in the Grant Lake Formation? These are all examples of the
types of questions this study will try to answer.
