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Age and Timing of the Permian Mass Extinctions: U/Pb Dating of Closed-System Zircons
Roland Mundil,1Kenneth R. Ludwig,1Ian Metcalfe,2Paul R. Renne1,3
The age and timing of the Permian-Triassic mass extinction havebeen difficult to determine because zircon populations fromthe type sections are typically affected by pervasive lead lossand contamination by indistinguishable older xenocrysts. Zirconsfrom nine ash beds within the Shangsi and Meishan sections (China),pretreated by annealing followed by partial attack with hydrofluoricacid, result in suites of consistent and concordant uranium/lead(U/Pb) ages, eliminating the effects of lead loss. The U/Pbage of the main pulse of the extinction is 252.6 ± 0.2million years, synchronous with the Siberian flood volcanism,and it occurred within the quoted uncertainty.
1 Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709, USA. 2 Asia Centre, University of New England, Armidale NSW 2351, Australia. 3 Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA.
Biomagnetostratigraphy of the Vikinghogda Formation, Svalbard (Arctic Norway), and the geomagnetic polarity timescale for the Lower Triassic.
M. W. Hounslow, C. Peters, A. Mork, W. Weitschat, and J. O. Vigran (2008)
Geological Society of America Bulletin
120, 1305-1325
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Diversity and Distribution of Triassic Bryozoans in the Aftermath of the End-Permian Mass Extinction.
New age constraints for the Ordovician Tyrone Volcanic Group, Northern Ireland.
M.R. COOPER, Q.G. CROWLEY, and A.W.A. RUSHTON (2008)
Journal of the Geological Society
165, 333-339
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ERWIN, D. H. 2006. Extinction. How Life on Earth Nearly Ended 250 Million Years Ago.: ix + 296 pp. Princeton, Oxford: Princeton University Press. Price US $24.95 (hard covers). ISBN 0 691 00524 9..
I. Metcalfe (2008)
Geological Magazine
145, 151-152
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Geochronologic constraints on the chronostratigraphic framework of the Neoproterozoic Huqf Supergroup, Sultanate of Oman.
S. A. Bowring, J. P. Grotzinger, D. J. Condon, J. Ramezani, M. J. Newall, and P. A. Allen (2007)
Am J Sci
307, 1097-1145
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Bryozoan paleoecology indicates mid-Phanerozoic extinctions were the product of long-term environmental stress.
Smithian-Spathian boundary event: Evidence for global climatic change in the wake of the end-Permian biotic crisis.
T. Galfetti, P. A. Hochuli, A. Brayard, H. Bucher, H. Weissert, and J. O. Vigran (2007)
Geology
35, 291-294
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Evaluation of different models for the origin of the Siberian Traps.
A. V. Ivanov (2007)
Geological Society of America Special Papers
430, 669-691
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Timing of recovery from the end-Permian extinction: Geochronologic and biostratigraphic constraints from south China.
D. J. Lehrmann, J. Ramezani, S. A. Bowring, M. W. Martin, P. Montgomery, P. Enos, J. L. Payne, M. J. Orchard, W. Hongmei, and W. Jiayong (2006)
Geology
34, 1053-1056
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ENVIRONMENTAL AND BIOLOGICAL CONTROLS ON THE INITIATION AND GROWTH OF A MIDDLE TRIASSIC (ANISIAN) REEF COMPLEX ON THE GREAT BANK OF GUIZHOU, GUIZHOU PROVINCE, CHINA.
J. L. PAYNE, D. J. LEHRMANN, S. CHRISTENSEN, J. WEI, and A. H. KNOLL (2006)
Palaios
21, 325-343
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Cell evolution and Earth history: stasis and revolution.