Evidence of giant asteroid impact that occurred 300mn yrs ago in Australia
By ANISunday, October 24, 2010
MELBOURNE - An Aussie scientist has discovered evidence of a major asteroid impact that occurred near the Queensland-South Australia border more than 300 million years ago.
The asteroid, which produced a shock zone at least 80km wide, could be the second-largest asteroid ever found in Australia.
University of Queensland researcher Dr Tongu Uysal discovered the asteroid impact during his studies of the Cooper Basin, which is a large geothermal energy resource being developed on the border between Queensland and South Australia.
“I noticed that the quartz grains in the rock had unusual planar deformation features that indicated either it had been exposed to extreme tectonic pressure or a large asteroid impact,” the Courier Mail quotes Uysal as saying.
“The rock deformations were confirmed as being the result of an asteroid impact through microscopic examination of the quartz crystals and further laboratory tests.
“The results suggest that either a very large asteroid or a cluster of asteroids landed, but we need to do further testing to verify this,” Uysal added.
Uysal said the impact of the asteroid triggered a huge explosion and caused the ground water to boil and induce chemical and mineralogy changes in the surrounding rocks.
“This may have resulted in the reconcentration of various heat-producing elements which has made the Cooper Basin such a rich source of geothermal energy today,” Uysal added.
The land surface that the asteroid hit is now buried under layers of sedimentary rock and Uysal thinks the original crater has most likely eroded away.
Australia’s largest recorded asteroid impact is at Woodleigh, east of Shark Bay in Western Australia.
The Woodleigh impact structure is 120km in diameter and was produced by an asteroid six to 12km across, about 360 million years ago.
Uysal, along with Dr Andrew Glikson from the Australian National University, will present his findings at the Australian Geothermal Energy Conference in Adelaide from November 19. (ANI)
