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Extinction of Cloudina and Namacalathus at the Precambrian-Cambrian boundary in Oman

Joachim E. Amthor, John P. Grotzinger, Stefan Schroeder, Samuel A. Bowring, Jahandar Ramezani, Mark W. Martin and Albert Matter
Extinction of Cloudina and Namacalathus at the Precambrian-Cambrian boundary in Oman
Geology (Boulder) (May 2003) 31 (5): 431-434

Abstract

Biostratigraphic, carbon isotope, and U-Pb zircon geochronological data from the Ara Group of Oman indicate an abrupt last appearance of Cloudina and Namacalathus coincident with a large-magnitude, but short-lived negative excursion in the carbon isotope composition of seawater that is globally coincident with the Precambrian-Cambrian boundary. U-Pb zircon age data from an intercalated ash bed directly define this negative excursion to be at 542.0+ or -0.3 Ma, consistent with previous age constraints from Siberia and Namibia. Combined with the global biostratigraphic record, these new data strengthen hypotheses invoking mass extinction within terminal Proterozoic ecosystems at or near the Precambrian-Cambrian boundary.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 31
Serial Issue: 5
Title: Extinction of Cloudina and Namacalathus at the Precambrian-Cambrian boundary in Oman
Affiliation: Petroleum Development Oman, Muscat, Oman
Pages: 431-434
Published: 200305
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 17
Accession Number: 2003-046297
Categories: Stratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Annotation: With GSA Data Repository Item 2003058
Illustration Description: illus. incl. sect., sketch map
N17°00'00" - N27°00'00", E52°30'00" - E60°00'00"
Secondary Affiliation: Massachusetts Institute of Technology, USA, United StatesUniversitaet Bern, CHE, Switzerland
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 200315
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