It was a mighty blast from outer space!
Scientists from The Australian National University (ANU) have identified a dome at least 50 kilometers in diameter, buried under the Timor Sea – a sea bounded to the north by the island of Timor, to the east by the Arafura Sea, to the south by Australia and to the west by the Indian Ocean.
The feature was created by a giant asteroid that collided with Earth around 35 million years ago – a period of heavy extraterrestrial bombardment.
Their findings could suggest a link between these impacts and a sharp fall in global temperatures preceding the formation of the Antarctic ice sheet. The research has been published in the new issue of the Australian Journal of Earth Sciences.
The finding is based on oil company cuttings from a deep ocean well.
“The identification of microstructural and chemical features in drill fragments taken from the Mount Ashmore drill hole revealed evidence of a significant impact,” said Andrew Glikson, a specialist in the study of extraterrestrial impacts of the Planetary Science Institute and the School of Archaeology and Anthropology at ANU.
The full size of the impact crater is not yet defined.
“Round the same time as the Mount Ashmore impact, a 100 kilometer (km) wide asteroid impact structure formed in Siberia, and another measuring 85 km in diameter in Chesapeake Bay, off Virginia, in the United States. Likewise a large field of tektites – molten rock fragments splashed by impact – fell over northeast America. This defined a major impact cluster across the planet,” Glikson noted in a May 20 press statement.
Glikson said that the increase in geophysical surveys and drilling associated with oil exploration over the last few decades has allowed the identification of a number of large impact structures onshore and off the coast of Western Australia.
By LD/CSE