Late Middle and early Late Ordovician history of the Cincinnati arch province, central Kentucky to central Tennessee

Abstract

Research Article| October 01, 1978 Late Middle and early Late Ordovician history of the Cincinnati arch province, central Kentucky to central Tennessee PETER E. BORELLA; PETER E. BORELLA 1Physical Sciences Department, Riverside City College, Riverside, California 92506 Search for other works by this author on: GSW Google Scholar ROBERT H. OSBORNE ROBERT H. OSBORNE 2Department of Geological Sciences, University of Southern California, Los Angeles, California 90007 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1978) 89 (10): 1559–1573. https://doi.org/10.1130/0016-7606(1978)89<1559:LMAELO>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation PETER E. BORELLA, ROBERT H. OSBORNE; Late Middle and early Late Ordovician history of the Cincinnati arch province, central Kentucky to central Tennessee. GSA Bulletin 1978;; 89 (10): 1559–1573. doi: https://doi.org/10.1130/0016-7606(1978)89<1559:LMAELO>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Six limestone classes occur in the Ordovician strata from Lexington, Kentucky, to Nashville, Tennessee. Sediments that make up classes 1 through 4 were deposited in "open" epicontinental marine environments, whereas classes 5 and 6 reflect more "restricted" environments. These classes were used to calculate relative mechanical energy and depth indices for a defined time-stratigraphic interval. The base of this interval is a bentonite bed that occurs near the base of the Brannon Member of the Lexington Limestone, and the top is defined by a major change in the relative abundance of platform conodonts. Relative mechanical energy and depth contours intersect the present axis of the Cincinnati arch at a high angle, which suggests that a continuous arch was not present. Shoal environments existed in the Lexington area and northeast of the present Nashville dome. These shoals correspond to the positions of the Lexington and Nashville domes or precursors to these domes which were present during the defined time interval. Paleobathymetric contours parallel east- and south-trending normal faults that are present in and south of the Lexington, Kentucky, area. This suggests that these faults were active during late Middle Ordovician time and were partly responsible for creating the bathymetric relief necessary for higher-energy carbonate sediments to accumulate. Deeper-water environments between the two shoal areas reflect the presence of the Rome trough. The general bathymetric trend for these strata is one of submergence. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.