IMPROVING CHRONOSTRATIGRAPHIC CORRELATION OF WENLOCK-PRIDOLI (SILURIAN) STRATA OF THE APPALACHIAN FORELAND BASIN (VIRGINIA, WEST VIRGINIA, OHIO) THROUGH THE USE OF HIGH-RESOLUTION EVENT STRATIGRAPHY (HIRES)

Global chronostratigraphic correlation of Silurian strata in the Virginia, West Virginia, and eastern Ohio portion of the Appalachian Basin has been difficult due to a lack of zonally diagnostic fauna. Here, we present the results of an integrated high-resolution conodont biostratigraphy, carbon isotope chemostratigraphy, and sequence stratigraphy (i.e., HiRES methodologies) of core and outcrop from classical and new sections to improve the global chronostratigraphic correlation of these units. Classical sections include those previously sampled by C. T. Helfrich, as well as a previously unsampled core from the Ohio Geological Survey.

Initial findings demonstrate the need for significant chronostratigraphic recalibration of strata within the Mifflintown through Tonoloway formations with respect to Silurian series and stage boundaries, by more than a series in some cases. In addition to new conodont biostratigraphic data, our new δ¹³C_carb data demonstrate the presence of the early Sheinwoodian ‘Ireviken’ and Homerian ‘Mulde’ positive carbon isotope excursions in the Appalachian Basin sections. The improved biostratigraphy and integrated carbon isotope stratigraphy significantly improves our ability to correlate these strata with the global Silurian stage boundaries and utilize the Appalachian Basin succession to investigate global vs. regional patterns of Silurian eustasy, sequence stratigraphy, geochemistry, and evolution.