found it, 2 threads
http://www.freerepublic.com/focus/f-news/1642426/posts
http://www.freerepublic.com/focus/f-news/1641966/posts
300-mile diameter impact crater.
or is it 30-miles wide? sigh the article is not clear.
“The 300-mile-wide crater lies hidden more than a mile beneath the East Antarctic Ice Sheet. And the gravity measurements that reveal its existence suggest that it could date back about 250 million years — the time of the Permian-Triassic extinction, when almost all animal life on Earth died out.
Its size and location — in the Wilkes Land region of East Antarctica, south of Australia — also suggest that it could have begun the breakup of the Gondwana supercontinent by creating the tectonic rift that pushed Australia northward.
Scientists believe that the Permian-Triassic extinction paved the way for the dinosaurs to rise to prominence. The Wilkes Land crater is more than twice the size of the Chicxulub crater in the Yucatan peninsula, which marks the impact that may have ultimately killed the dinosaurs 65 million years ago. The Chicxulub meteor is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide — four or five times wider.”
one more like WoofDog’s:
Does a giant crater lie beneath the Antarctic ice?
nature news | 2 06 | Mark Peplow
Posted on 06/05/2006 12:07:10 PM EDT by S0122017
http://www.freerepublic.com/focus/f-chat/1643681/posts