Timing of recovery from the end-Permian extinction: Geochronologic and biostratigraphic constraints from south China
- Daniel J. Lehrmann*1,
- Jahandar Ramezani2,
- Samuel A. Bowring2,
- Mark W. Martin†2,
- Paul Montgomery#3,
- Paul Enos3,
- Jonathan L. Payne4,
- Michael J. Orchard5,
- Wang Hongmei6 and
- Wei Jiayong6
- 1Department of Geology, University of Wisconsin–Oshkosh, Oshkosh, Wisconsin 54901, USA
- 2Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- 3Department of Geology, University of Kansas, Lawrence, Kansas 66045, USA
- 4Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305, USA
- 5Geological Survey of Canada, Vancouver, BC V6B 5J3, Canada
- 6Guizhou Bureau of Geology and Mineral Resources, Guiyang, Guizhou, People's Republic of China
Abstract
Four volcanic-ash beds bracket the Early-Middle Triassic boundary, as defined by conodont biostratigraphy, in a stratigraphic section in south China. High-precision U-Pb dates of single zircons allow us to place the Early to Middle Triassic (Olenekian-Anisian) boundary at 247.2 Ma. Magnetic-reversal stratigraphy allows global correlation. The new dates constrain the Early Triassic interval characterized by delayed biotic recovery and carbon-cycle instability to ∼5 m.y. This time constraint must be considered in any model for the end-Permian extinction and subsequent recovery.
Footnotes
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↵†Current address: Shell International Exploration and Production, Houston, Texas 77099, USA
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↵*lehrmann{at}uwosh.edu
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↵#Current address: Chevron Australia Pty Ltd., Perth, 6000, Australia
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↵GSA Data Repository item 2006229, analytical methods and additional data for U-Pb geochronology, magnetic-reversal stratigraphy, and conodont biostratigraphy, is available online at http://www.geosociety.org/pubs/ft2006.htm, or on request from editing{at}geosociety.org or Documents Secretary, GSA, P.O. Box 9140, Boulder, CO 80301, USA.
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- Accepted 14 July 2006.
- Received 26 March 2006.
- Revision received 4 July 2006.
- The Geological Society of America, Inc.
