Sydney: Australian scientists have discovered
a crater deep beneath the Timor Sea made during a heavy meteor
storm which may have altered the Earth's climate, the lead
researcher said Thursday.
Australian National University archaeologist Andrew
Glikson said seismic activity led experts to the Mount Ashmore
1B site, and a study of fragments showed a large meteorite hit
just before the Earth's temperatures plunged.
"The identification of microstructural and chemical
features in drill fragments taken from the Mount Ashmore drill
hole revealed evidence of a significant impact," Glikson said,
adding it was at least 50 kilometres (31 miles) wide and about
35 million years old.
A meteorite 100 kilometres wide hit Siberia at the same
time, along with an 85 km one in Chesapeake Bay, off the US
coast of Virginia, followed by a large field of molten rock
fragments over northeast America, he said.
"This defined a major impact cluster across the planet,"
said Glikson.
Glikson said the findings, published in the latest issue
of the Australian Journal of Earth Sciences, could suggest a
link between the impacts and a sharp fall in global
temperatures which preceded the formation of the Antarctic ice
sheet.
PTI
First Published: Thursday, May 20, 2010, 17:52