Northeastern Section - 44th Annual Meeting (2224 March 2009)
Paper No. 28-1
Presentation Time: 8:00 AM-8:20 AM

MICROSTRATIGRAPHIC INTERPRETATIONS OF RELATIVE OXYGEN LEVELS FROM DEVONIAN BLACK SHALES OF NEW YORK STATE

BOYER, Diana L., Earth Sciences, SUNY Oswego, 240 Piez Hall, Oswego, NY 13126, dboyer@oswego.edu and DROSER, Mary L., Earth Sciences, University of California, Riverside, Riverside, CA 92521

High-resolution variation in relative bottom water oxygen levels is recognized from body and trace fossil data preserved in Devonian aged black shales of central and western New York. The ichnological signal is described based on burrow size, relative amount of bioturbation (ichnofabric index), and ichnogeneric diversity. Devonian dysaerobic trace fossils are consistently very small in size with approximately 90% of burrows disrupting the sediment less than 0.5 cm in depth and 94% of burrows less than 0.5 cm in width. The small size of burrows obscures cross cutting relationships typically used in post-Paleozoic strata to interpret relative oxygen levels; however variation in burrow size is correlative with inferred relative oxygen levels. Maximum burrow diameter, based on fundamental physiological oxygen demands of infaunal organisms, combined with relative amount of bioturbation, and body fossil data provide high resolution through the dysaerobic zone. Relative oxygen curves derived from the combined trace fossil and body fossil signal allow the recognition of variation in relative bottom water oxygen levels on a cm scale through multiple units representing a range of dysaerobic conditions. The scale of resolution determined using biological signals is at a finer scale of resolution that produced through several geochemical proxies including several iron proxies, sulfur isotope data and a range of trace metals including Mo and Mn.

Northeastern Section - 44th Annual Meeting (2224 March 2009)
General Information for this Meeting
Session No. 28
Advances in Stratigraphy and Paleontology of Paleozoic Dark Shales
Holiday Inn By the Bay: Connecticut Room
8:00 AM-10:00 AM, Monday, 23 March 2009

Geological Society of America Abstracts with Programs, Vol. 41, No. 3, p. 38

© Copyright 2009 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.