High-resolution event stratigraphy (HiRES) of the Silurian across the Cincinnati Arch (USA) through integrating conodont and carbon isotope biochemostratigraphy, with gamma-ray and sequence stratigraphy

ABSTRACT

Silurian strata within the tristate area of Indiana, Ohio, and Kentucky have been thoroughly studied for well over a century. Due to rapid facies changes throughout the region numerous lithostratigraphic terminologies were established, many of which were difficult to correlate even over short distances. Recently these stratigraphic complexities have received renewed interest due to advancements in bio-, chemo-, and sequence stratigraphy that greatly improved our understanding of the tristate area. These improvements had significant implications for our ability to correlate Rhuddanian through lower Sheinwoodian strata between the Appalachian and Illinois basins and allowed unified nomenclatural and sequence stratigraphic hierarchies for this interval to be developed across the Cincinnati Arch. Recent advancements in regional chronostratigraphy of Silurian strata, however, highlight several discrepancies with regards to the 3^rd- and 4^th-order sequence stratigraphic hierarchies assigned within these basins. In an effort to alleviate these points of disagreement, we contribute new δ¹³C_carb chemostratigraphic and sequence stratigraphic analyses of a basinward Appalachian section from Scioto County, Ohio, spanning upper Telychian through Gorstian strata assigned to the Estill through Tymochtee formations, complemented by gamma-ray core scans for localities traversing northwestward from the sampled core section into western Ohio. These new data allow unified nomenclatural and sequence stratigraphic hierarchies to be developed throughout the region for strata spanning the upper Telychian through Gorstian stages. Additionally, these findings highlight a significant shift in the primary sites of sediment accommodation during the studied depositional interval.

KEYWORDS:

• Ohio
• Indiana
• Kentucky
• Appalachian Basin
• Illinois Basin

Acknowledgments

We would like to thank Jeffrey Deisher, the core librarian at the OGS, for providing spectral gamma ray scans of the Franklin Furnace Core from Scioto County, Ohio, and for providing access to core at the OGS H.R. Collins Lab and Core Repository. We would also like to thank Christopher Waid at the OGS for providing subsurface geophysical data and Mark Kleffner at The Ohio State University for discussion of regional biostratigraphy. Andy Stacey, a former employee at the University of Iowa Department of Earth and Environmental Sciences, acted as an assistant in the analysis of the Franklin Furnace Core, and we are very appreciative of the help he provided. This work was partially supported by the National Science Foundation Career Grant 1455030 awarded to Dr. B.D. Cramer, and the American Chemical Society – Petroleum Research Fund Doctoral New Investigator Grant 53196-DNI8. The Department of Earth and Environmental Sciences at the University of Iowa also provided funding to assist with research and travel expenses. Lastly, we thank Mikael Calner (Lund University) and an anonymous reviewer for their constructive reviews that greatly improved this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was partially supported by the National Science Foundation Career Grant 1455030 awarded to Dr. B.D. Cramer and by the American Chemical Society – Petroleum Research Fund Doctoral New Investigator Grant 53196-DNI8.