Abstract
The Upper Ordovician Cincinnatian Series is a critical upper Katian reference succession. Previously, six 3rd-order depositional sequences (C1 to C6) have been recognized and frequently used as regional time slices. Recent research, however, indicates a need for revision and additions, including the recognition of additional 3rd- and 4th-order sequences. We propose amendments based upon high-resolution correlations using a combination of regional disconformities, cycle stacking patterns, bioevents, marker beds, and chemostratigraphy. Several disconformities, including a large regionally angular mid-Richmondian unconformity, are newly recognized or reinterpreted. In addition, distinctive depositional patterns aid in the recognition of systems tracts, with a) thick proximal laminated peritidal facies representing early transgressive systems tracts (TSTs) or lowstands, in part (LSTs), b) shell-rich limestone packages representing later TSTs and overlain by c) more shale-prone highstand systems tracts (HSTs), themselves overlain locally by d) siliciclastic dominated falling stage systems tract (FSST) deposits that are commonly removed beneath substantial unconformities (sequence boundaries). At present, we recognize eight 3rd-order Cincinnatian sequences, designated C1 through C8, and 16 4th-order subdivisions and their component systems tracts. A younger (Hirnantian?) sequence may be present at some localities as the enigmatic Centerville Formation and/or basal Belfast Member of the Brassfield Formation. The implications of these new correlations and sequence interpretations include a new standard for relative sea-level changes and insights into basin dynamics. This framework also permits a more nuanced history of biotic changes that include geologically brief pulses of immigration associated with the transgressions of the C1 (lower Kope Formation), C5C (Clarksville Member of Waynesville Formation), and C7A (basal Whitewater Formation).
Original language | English |
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Article number | 109483 |
Journal | Palaeogeography, Palaeoclimatology, Palaeoecology |
Volume | 540 |
DOIs | |
State | Published - Feb 15 2020 |
Bibliographical note
Funding Information:We extend our sincere thanks to the many colleagues and students who have aided us in our field work, discussions, and publications, including Brad Deline, Steve Holland, T.J. Malgieri, Nathan Marshall, Charles Mitchell, Tim Paton, Alex Reis, Tom Schramm, James Thomka, and Allison Young. Further gratitude goes to the late Stephen Felton, as well as Tom Bantel, Don Bissett, Dan Cooper, Ron Fine, Rich Fuchs, Bill Heimbrock, Jack Kallmeyer, Jerry Rush, and dozens of other members of the Cincinnati Dry Dredgers. We are also grateful to David Meyer and Arnie Miller for insightful discussions and Richard A. Davis for his online Bibliography on the Type-Cincinnatian ( faculty.msj.edu/davisr/cintian/biblio.htm ). We also greatly appreciate careful reviews of the paper by André Desrochers, Brenda Hunda, and Alycia Stigall, which greatly improved the manuscript. CB also acknowledges, as always, help with photography editing and support from Betty-Lou Brett; his past research on Ordovician was supported by grants from the Petroleum Research Fund, American Chemical Society , from NSF grant EAR 0819715 , and a grant from the Hess Corporation . Dattilo acknowledges the donors of the American Chemical Society Petroleum Research Fund grant 5525-UR8 for partial support of this research. This paper is a contribution to the International Geoscience Programme (IGCP) Project 653 –The Onset of the Great Ordovician Biodiversification Event.
Funding Information:
We extend our sincere thanks to the many colleagues and students who have aided us in our field work, discussions, and publications, including Brad Deline, Steve Holland, T.J. Malgieri, Nathan Marshall, Charles Mitchell, Tim Paton, Alex Reis, Tom Schramm, James Thomka, and Allison Young. Further gratitude goes to the late Stephen Felton, as well as Tom Bantel, Don Bissett, Dan Cooper, Ron Fine, Rich Fuchs, Bill Heimbrock, Jack Kallmeyer, Jerry Rush, and dozens of other members of the Cincinnati Dry Dredgers. We are also grateful to David Meyer and Arnie Miller for insightful discussions and Richard A. Davis for his online Bibliography on the Type-Cincinnatian (faculty.msj.edu/davisr/cintian/biblio.htm). We also greatly appreciate careful reviews of the paper by Andr? Desrochers, Brenda Hunda, and Alycia Stigall, which greatly improved the manuscript. CB also acknowledges, as always, help with photography editing and support from Betty-Lou Brett; his past research on Ordovician was supported by grants from the Petroleum Research Fund, American Chemical Society, from NSF grant EAR 0819715, and a grant from the Hess Corporation. Dattilo acknowledges the donors of the American Chemical Society Petroleum Research Fund grant 5525-UR8 for partial support of this research. This paper is a contribution to the International Geoscience Programme (IGCP) Project 653?The Onset of the Great Ordovician Biodiversification Event.
Publisher Copyright:
© 2019 Elsevier B.V.
Keywords
- Bioevents
- Epiboles
- Ordovician
- Richmondian invasion
- Sequence stratigraphy
- Unconformity
ASJC Scopus subject areas
- Oceanography
- Ecology, Evolution, Behavior and Systematics
- Earth-Surface Processes
- Paleontology