North-Central Section (44th Annual) and South-Central Section (44th Annual) Joint Meeting (1113 April 2010)
Paper No. 29-4
Presentation Time: 1:30 PM-5:00 PM

IDENTIFYING CYCLICITY IN THE LITHOLOGICALLY MONOTONOUS UPPER ORDOVICIAN (CINCINNATIAN) BELLEVUE FORMATION: A TEST OF THE UTILITY OF TAPHONOMIC AND PALEOECOLOGICAL ANALYSES FOR CYCLE RECOGNITION

WISE, Julia Linnaea, Geology, University of Cincinnati, 500 Geology/Physics Building, Cincinnati, OH 45221-0013, julia.wise19@gmail.com, KOLBE, Sarah E., Department of Geology, University of Cincinnati, 500 Geo/Phys, Cincinnati, OH 45221-0013, ZAMBITO, James J. IV, Department of Geology, University of Cincinnati, 500 Geology/Physics Building, Cincinnati, OH 45221-0013, BRETT, Carlton, Department of Geology, Univ of Cincinnati, 500 Geology/Physics Bldg, Cincinnati, OH 45221-0013, and WILSON, Ryan David, Indiana University, Bloomington, IN 47405-1405

Interpreting monotonous sections in the rock record presents a challenge because of the lack of lithological features typically used to diagnose environmental and temporal change at the outcrop scale. This study uses the taphonomy and paleoecology of fossil assemblages collected from the Bellevue Formation (Cincinnatian, Maysvillian, C-2 Sequence) to test three hypotheses related to the identification of sedimentary cycles. First, that color variation of brachiopod fossils can be meaningfully related to degree of time-averaging, with dark coloration positively correlated with other taphonomic features such as fragmentation and corrosion. Second, variations in taphonomy accurately reflect changes in environment as indicated by independent evidence such as fossil assemblages. Third, that taphonomy and paleoecology can be used to recognize cyclicity in an otherwise monotonous section.

Field observations of lithology, taphonomy, and paleoecology were made within a high-resolution stratigraphic framework. Multiple brachiopod specimens from each bed were examined in the lab and detailed taphonomic data were recorded, including: corrosion, articulation, color alteration, location of the brachiopod in the bed, orientation of the valve, fragmentation, encrustation, boring, and breaching of the valves. Numerical scores were assigned to the taphonomic data, allowing for multivariate analysis to be applied to all the data. In addition, taxon presence/absence and abundance data were collected for all beds throughout the section, and beds were described lithologically. Statistical analysis suggests that coloration is a meaningful taphonomic indicator. Additionally, analysis also shows correspondence between many of the taphonomic characters studied. Comparison of taphonomic indicators with the results of paleoecological ordination analysis suggests a relationship and underscores the utility of a combined taphonomic and paleoecological approach in recognizing cyclicity.

North-Central Section (44th Annual) and South-Central Section (44th Annual) Joint Meeting (1113 April 2010)
General Information for this Meeting
Session No. 29--Booth# 26
General Paleontology (Posters)
Branson Convention Center: Taneycomo A
1:30 PM-5:00 PM, Monday, 12 April 2010

Geological Society of America Abstracts with Programs, Vol. 42, No. 2, p. 83

© Copyright 2010 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.