Bedout: a possible end-Permian impact crater offshore of northwestern Australia.
Science
; 304(5676): 1469-76, 2004 Jun 04.
Article
em En
| MEDLINE
| ID: mdl-15143216
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.
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Base de dados:
MEDLINE
Assunto principal:
Meteoroides
/
Sedimentos Geológicos
Tipo de estudo:
Prognostic_studies
País/Região como assunto:
Oceania
Idioma:
En
Revista:
Science
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos