Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Science Careers Booklet

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Published Online May 13, 2004
Science DOI: 10.1126/science.1093925

Research Articles

Submitted on November 20, 2003
Accepted on April 28, 2004

Bedout: A Possible End-Permian Impact Crater Offshore of Northwestern Australia

L. Becker 1*, R. J. Poreda 2, A. R. Basu 2, K. O. Pope 3, T. M. Harrison 4, C. Nicholson 1, R. Iasky 5

1 Institute for Crustal Studies, Department of Geological Sciences, University of California, Santa Barbara, CA 93106, USA.
2 Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY, USA.
3 Geo Eco Arc Research, Aquasco, MD 20608, USA.
4 Australian National University, Canberra, Australia.
5 Geological Survey Western Australia, Perth, Australia.

* To whom correspondence should be addressed.
L. Becker , E-mail: lbecker{at}crustal.ucsb.edu

The Bedout High located on the northwestern continental margin of Australia has emerged as a prime candidate for an end Permian impact structure. Seismic imaging, gravity data and the identification of melt rocks and impact breccias from drill cores located on top of Bedout are consistent with the presence of a buried impact crater. The impact breccias contain nearly pure silica glass (SiO2), fractured and shock-melted plagioclases and spherulitic glass. The distribution of glass and shocked minerals over hundreds of meters of drill core implies that a melt sheet is present. Available gravity and seismic data suggest that the Bedout High represents the central uplift of a crater similar in size to Chicxulub. A plagioclase separate from the Lagrange-1 exploration well has an Ar/Ar age of 250.1 ± 4.5 million years. The location, size and age of the Bedout crater can account for reported occurrences of impact debris in Permian-Triassic boundary sediments worldwide.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Diversity and Distribution of Triassic Bryozoans in the Aftermath of the End-Permian Mass Extinction.
C. M. Powers and J. F. Pachut (2008)
Journal of Paleontology 82, 362-371
   Abstract »    Full Text »    PDF »
Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling.
R. B. Firestone, A. West, J. P. Kennett, L. Becker, T. E. Bunch, Z. S. Revay, P. H. Schultz, T. Belgya, D. J. Kennett, J. M. Erlandson, et al. (2007)
PNAS 104, 16016-16021
   Abstract »    Full Text »    PDF »
The geochronology of large igneous provinces, terrestrial impact craters, and their relationship to mass extinctions on Earth.
S. Kelley (2007)
Journal of the Geological Society 164, 923-936
   Abstract »    Full Text »    PDF »
END-PERMIAN MASS EXTINCTION OF LAGENIDE FORAMINIFERS IN THE SOUTHERN ALPS (NORTHERN ITALY).
J. R. GROVES, R. RETTORI, J. L. PAYNE, M. D. BOYCE, and D. ALTINER (2007)
Journal of Paleontology 81, 415-434
   Abstract »    Full Text »    PDF »
Revolutions in the Earth Sciences: Continental Drift, Impact and other Catastrophes.
W. U. Reimold (2007)
South African Journal of Geology 110, 1-46
   Abstract »    Full Text »    PDF »
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
   Abstract »    Full Text »    PDF »
Middle-Late Permian mass extinction on land.
G. J. Retallack, C. A. Metzger, T. Greaver, A. H. Jahren, R. M.H. Smith, and N. D. Sheldon (2006)
GSA Bulletin 118, 1398-1411
   Abstract »    Full Text »    PDF »
The Pattern and Timing of Biotic Recovery from the End-Permian Extinction on the Great Bank of Guizhou, Guizhou Province, China.
J. L. PAYNE, D. J. LEHRMANN, J. WEI, and A. H. KNOLL (2006)
Palaios 21, 63-85
   Abstract »    Full Text »    PDF »
Catastrophic soil erosion during the end-Permian biotic crisis.
M. A. Sephton, C. V. Looy, H. Brinkhuis, P. B. Wignall, J. W. de Leeuw, and H. Visscher (2005)
Geology 33, 941-944
   Abstract »    Full Text »    PDF »
Earliest Triassic Claystone Breccias and Soil-Erosion Crisis.
G.J. Retallack (2005)
Journal of Sedimentary Research 75, 679-695
   Abstract »    Full Text »    PDF »
Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the Karoo Basin, South Africa.
P. D. Ward, J. Botha, R. Buick, M. O. De Kock, D. H. Erwin, G. H. Garrison, J. L. Kirschvink, and R. Smith (2005)
Science 307, 709-714
   Abstract »    Full Text »    PDF »
Comment on "Bedout: A Possible End-Permian Impact Crater Offshore of Northwestern Australia".
A. Glikson (2004)
Science 306, 613b
   Full Text »    PDF »
Response to Comment on "Bedout: A Possible End-Permian Impact Crater Offshore of Northwestern Australia".
L. Becker, R. J. Poreda, A. R. Basu, K. O. Pope, T. M. Harrison, C. Nicholson, and R. Iasky (2004)
Science 306, 613c
   Full Text »    PDF »
Age and Timing of the Permian Mass Extinctions: U/Pb Dating of Closed-System Zircons.
R. Mundil, K. R. Ludwig, I. Metcalfe, and P. R. Renne (2004)
Science 305, 1760-1763
   Abstract »    Full Text »    PDF »
The complexity of mass extinction.
H. W. Pfefferkorn (2004)
PNAS 101, 12779-12780
   Full Text »    PDF »
Large Perturbations of the Carbon Cycle During Recovery from the End-Permian Extinction.
J. L. Payne, D. J. Lehrmann, J. Wei, M. J. Orchard, D. P. Schrag, and A. H. Knoll (2004)
Science 305, 506-509
   Abstract »    Full Text »    PDF »


ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products