|Bedout: a possible End-Permian impact crater offshore of Northwestern Australia|
Becker, L.; Poreda, R.J.; Basu, A.R.; Pope, K.O.; Harrison, T.M.; Nicholson, C.; Iasky, R. (2004). Bedout: a possible End-Permian impact crater offshore of Northwestern Australia. Science (Wash.) 304(5676): 1469-1476
In: Science (Washington). American Association for the Advancement of Science: New York, N.Y. ISSN 0036-8075, more
|Authors|| || Top |
- Becker, L.
- Poreda, R.J.
- Basu, A.R.
- Pope, K.O.
- Harrison, T.M.
- Nicholson, C.
- Iasky, R.
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.