Document Type
Article
Publication Date
1-1-2002
Publication Title
Geology
Abstract
This study illustrates the usefulness of carbon isotopes in stratigraphic interpretations of poorly fossiliferous strata beyond the resolution possible by biostratigraphy. The Upper Cambrian strata of the lower Gorge Formation in northwestern Vermont have been interpreted as highly condensed continental-slope deposits with a hiatus bracketed by the trilobite fauna of the Dunderbergia zone (Steptoean) and the Saukia zone (upper Sunwaptan). This interpretation was based on information from two thin fossiliferous intervals, the occurrence of one of them being unconfirmed in a recent study. Carbon isotopes provide a means for testing this interpretation because marine carbonate rocks deposited during the Steptoean Age of the Late Cambrian record a large, global, positive carbon isotope excursion (δ13C values of up to +5‰ relative to the Vienna Peedee belemnite standard). If the proposed age for the lowermost Gorge Formation is correct, these strata should record the start of the excursion, and the hiatus should produce an abrupt termination in the record of the excursion near maximum values. The determined δ13C values (-0.57% to +0.39%) indicate that the excursion is not recorded at this locality. The results question the age for these strata and suggest that the hiatus is greater than previously recognized, encompassing most of the Steptoean. This major sedimentary hiatus lends supporting evidence for a significant eustatic or pan-Laurentian sea-level event during the Steptoean perturbation in the global cycling of carbon.
Keywords
Cambrian, Carbon isotopes, Gorge formation, Stratigraphy, Vermont
Volume
30
Issue
6
First Page
563
Last Page
566
DOI
10.1130/0091-7613(2002)030<0563:SIOCAA>2.0.CO;2
ISSN
00917613
Rights
© 2002 Geological Society of America
Recommended Citation
Glumac, Bosiljka and Spivak-Birndorf, Malkah L., "Stable Isotopes of Carbon as an Invaluable Stratigraphic Tool: An Example from the Cambrian of the Northern Appalachians, USA" (2002). Geosciences: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/geo_facpubs/160
Comments
Archived as published. Open access article.