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Introduction: The Upper Ordovician rocks of the Cincinnati region are among the most fossiliferous in the world. They contain an extraordinary number of individual fossils and an unmatched diversity of marine invertebrate species. Because of the ease of access to the outcrops (mostly roadcuts and small quarries), the Cincinnatian rocks are an ideal field laboratory in which to study ancient life in an ocean which existed 450 million years ago. The Invertebrate Paleontology class at The College of Wooster is studying three units in the Richmondian Stage of the Cincinnatian Series (the Whitewater, Saluda and Liberty "formations") in southeastern Indiana. Our goal is to assemble a paleoecological reconstruction of the communities and environments present in this place and time. Our primary hypothesis is that despite sorting of fossils by storm events, we will still see an array of communities along an energy/depth gradient in these rocks. We will test several other subsidiary hypotheses as the semester continues. |
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Methods: Fueled primarily by doughnuts, we spent September 12th on two sets of outcrops in southeastern Indiana: the first near the city of Richmond and the second about 22 miles south near the town of Liberty. Detailed driving instructions, our schedule, two field images, the stratigraphy, and lists of expected fossils can be seen on our itinerary page. Each student made representative fossil and rock collections from the Whitewater, Saluda and Liberty units, using stratigraphic columns previously drawn. We spent the rest of the semester in the Wooster lab identifying the fossils, doing various biometric analyses, taking photographs, and making thin-sections and acetate peels. We will later dissolve some bulk limestone samples for conodonts and other microfossils. Each student specialized in some aspect of the paleocommunity analysis. Miranda Loflin, for example, concentrated on the strophomenid brachiopods, Aaron Shear on the orthids, Ryan McAllister on the bivalves, and so on. These students then produced short reports and photographic images for this project. This website will continue to grow with our work in the last few weeks of the semester. During the last laboratory session of the course we will hold a conference to develop our paleoecological conclusions for these Richmondian rocks and fossils. |
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The class spread out on the outcrop of the Saluda "formation" exposed 22 miles south of Richmond, Indiana. The yellowish color of the rocks is due to extensive dolomitization. The Saluda sediments were apparently deposited in significantly shallower water than the others. Aaron Shear is on the far left. |
The class is once again in the typical paleontological positions, this time on our third outcrop, that of the Liberty "formation". The lower angle of the slope shows that the unit contains more non-resistant claystone than the other two outcrops. Andrea Martin and Russ Kohrs are in the foreground. |
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Web Resources: Some websites to visit for information on our rocks and fossils are: the Keck Ohio pages (from this summer's project based in Wooster and ranging through northern Kentucky, southern Ohio and eastern Indiana); the Dry Dredgers page (maintained by an extraordinarily keen amateur group of collectors with professional standards and excellent eyes for Cincinnatian fossils); the Cincinnati Geology course page of Dr. Richard Davis (which has a comprehensive bibliography on Cincinnatian paleontology); and the excellent set of pages on the Ordovician of Kentucky maintained by the Kentucky Geological Survey. |
