129-29 Paired Organic and Carbonate Carbon Isotope Chemostratigraphy of the Ireviken Biogeochemical Event from Measley Ridge, Ohio

Abstract:

During the Silurian Period, the Ireviken Biogeochemical Event (IBE) was a major disruption to the global carbon cycle including an expansion of reducing environments and an extinction event. The IBE spans the Llandovery-Wenlock boundary, and the initiation of the event serves as a useful chronostratigraphic marker for the base of the Wenlock Series. Specifically, the organic and carbonate carbon isotope excursions associated with the IBE are an excellent chronostratigraphic marker that have been widely utilized for global chronostratigraphic correlation.

The Global Boundary Stratotype Section and Point (GSSP) for the base of the Wenlock Series is located at Hughley Brook in the United Kingdom, but this GSSP is currently under revision and a new location to place the GSSP is being sought. The current re-evaluation of the base Wenlock GSSP has initiated a search for potential Standard Auxiliary Boundary Stratotypes (SABSs) that may serve as important additional regional correlation tools for this position. The Measley Ridge outcrop in southern Ohio is a potential SABS candidate. Here, we present new paired organic and carbonate carbon isotope chemostratigraphy from the Measley Ridge section that clearly show the IBE in these strata and demonstrate that the carbon isotopic signature of this event can serve as an excellent chronostratigraphic marker for the base of the Wenlock Series.

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