|2011 GSA Annual Meeting in Minneapolis (9–12 October 2011)|
|Paper No. 27-7|
|Presentation Time: 9:00 AM-6:00 PM|
TRILOBITE BIOFACIES AND LITHOFACIES OF THE UPPER ORDOVICIAN (SANDBIAN) LEBANON LIMESTONE, NASHVILLE DOME, TENNESSEE
MOSS, David K., Department of Earth Sciences, Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY 13244, email@example.com and WESTROP, Stephen R., Oklahoma Museum of Natural History and School of Geology & Geophysics, Univ of Oklahoma, Norman, OK 73072|
The Late Ordovician (Sandbian) Lebanon Limestone of central Tennessee is a succession of subtidal carbonates that includes abundant, storm-generated bioclastic pack-, grain- and rudstone. The large lepiditicopid arthropod, Eoleperdita, is a conspicuous component of the rudstone facies, with bedding surfaces commonly crowded with disarticulated valves. The associated trilobite fauna is moderately diverse, including six to seven species, and is dominated by encrinurids and cheirurids. In the latter respect, it resembles more diverse biofacies of the younger Pooleville Member of the Bromide Formation of Oklahoma. Although the Lebanon Limestone has been interpreted by previous workers as a single depositional sequence (M3), a distinctive, regionally correlatable, sharp-based, meter-scale interval of grainstone near the middle of the formation, suggests a more complex stratigraphy. This grainstone unit, often referred to as the "Massive Member", may represent a TST of a second sequence, and is in turn overlain by a significant flooding surface and the deepest subtidal facies of the Lebanon. This deeper facies includes cm-thick lime mudstone layers with basal accumulations of graptolite rhabdosomes, some of which are current aligned, suggesting an origin as distal tempestites. The sparse, associated trilobite fauna is limited to low diversity assemblages of isotelines. Eoleperdita is also common in the graptolitic lime mudstone facies, indicating a broader bathymetric range than is typical for leperditicopid arthropods. Restriction of the group to shallow subtidal and peritidal settings apparently occurred later in its history.
2011 GSA Annual Meeting in Minneapolis (9–12 October 2011)
General Information for this Meeting
|Session No. 27--Booth# 48|
Paleontology (Posters) I: Ecology and Phylogeny
Minneapolis Convention Center: Hall C
9:00 AM-6:00 PM, Sunday, 9 October 2011
Geological Society of America Abstracts with Programs, Vol. 43, No. 5, p. 83
© Copyright 2011 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.