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 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. |