| Popis: |
The Upper Ordovician Waynesville Formation of the Ohio, Kentucky and Indiana tri-state region is situated during and between two major paleoecological events:, the Richmondian Invasion, and the End Ordovician Extinction. Because of this juxtaposition, understanding the regional stratigraphy of this interval is vital to interpreting these events. Stratigraphic and paleontological work on this interval dates back to the late 1800s, and, as a result, numerous nomenclature schemes (biostratigraphical, lithostratigraphical, and state-line geology) have been developed to characterize the Waynesville Formation. The variety of schemes has inhibited the ability to make detailed bed-by-bed correlations. This study has attempted to rectify this issue by selecting the best nomenclature scheme, and create bed-by-bed correlations that cross state lines. The results of the study herein demonstrate that correlations are indeed possible from the deepest water facies to the shallowest water facies fairly readily. The study has also resulted in the discovery of a Mid-Richmondian Unconformity which has previously gone undocumented. This unconformity, which separates the Waynesville Formation from the overlying Blanchester Formation, at places cuts through the entirety of the Clarksville Member of the Waynesville. If extended further south, this unconformity likely removes the Fort Ancient Member and the underlying Arnheim Formation. The discovery of Mid-Richmondian Unconformity will have important implications for paleoecological studies of this interval. |
