A new international study is looking at the impact of asteroid collisions on the evolution of life on Earth.
Research leader, Curtin University of Technology’s Dr Fred Jourdan, is working with researchers from the United States and Germany to review the age data on the Earth’s known impact craters.
“When we look back millions of years, it can be difficult to pinpoint the precise cause of mass extinction events,” Dr Jourdan said.
“Proving a cause-effect relationship between mass extinction and its origins requires fairly precise dates, which are currently available for only a small proportion of asteroid impacts.
“During our research, we have discovered that the ages of most major craters could not be accurately identified
“This means that they cannot be attributed to any of the known mass extinction events.”
Currently, out of 174 known major impact craters, only 11 have been accurately dated.
“Based on these 11 craters, we can only match one with a known mass extinction – the extinction of dinosaurs about 65 million years ago,” he said.
Dr Jourdan, a Research Fellow in Curtin’s Department of Applied Geology, said the dinosaur extinction was also ambiguous because major volcanic eruptions occurred in India at the same time.
“Of course, the asteroid falls that have created large impact craters must have had significant regional effect on life, but it seems that they rarely cause worldwide extinctions,” he said.
Australia has 26 confirmed impact craters, of which 10 are located in Western Australia.
“So far, none of the Australian impact craters have had their age precisely determined,” Dr Jourdan said.
“At this point we only have an estimate of their ages.”
The age of major impacts are being investigated by Curtin researchers by carefully dating impact rocks using radioactive techniques.
The study has been published in a special section of Earth and Planetary Science Letters (Frontiers), which publishes only four landmark research papers each year.