Bedout: a possible end-Permian impact crater offshore of northwestern Australia

Science. 2004 Jun 4;304(5676):1469-76. doi: 10.1126/science.1093925. Epub 2004 May 13.

Abstract

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 core material 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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Argon
  • Australia
  • Crystallization
  • Geography
  • Geologic Sediments*
  • Glass
  • Meteoroids*
  • Minerals
  • Radioisotopes
  • Silicon Dioxide

Substances

  • Minerals
  • Radioisotopes
  • Argon
  • Silicon Dioxide