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First Undersea Meteorite Crater Found Off Nova Scotia, Scientists Say

June 17, 1987

NEW YORK (AP) _ Scientists say they have identified the first known meteorite crater beneath an ocean, a huge depression about 124 miles southeast of Nova Scotia, Canada.

Further study could help explore the hypothesis that mass extinction can follow huge meteorite impacts, researchers Lubomir Jansa and Georgia Pe-Piper wrote in Thursday’s issue of the British journal Nature.

The crater was formed underwater 50 million years ago from the impact of a meteorite or the nucleus of a comet, wrote Jansa, of the Bedford Institute of Oceanography in Dartmouth, Nova Scotia, and Pe-Piper, of St. Mary’s University in Halifax, Nova Scotia.

The falling object must have measured about 1.25 miles to nearly two miles in diameter, they said.

The crater lies under about 370 feet of water near the edge of the continental shelf. It stretches at least 28 miles across, with an uplifted portion in the center that stands about a mile tall and seven miles across.

The crater holds rocks that bear evidence of having undergone tremendous shock, a sign of meteoritic impact.

Blyth Robertson, a research scientist with the Geological Survey of Canada, said it is the first documented finding of such a crater. A partially translated paper suggests Soviet scientists have found some presumed undersea craters, he said.

The mass-extinction theory cites unusually high levels of the element iridium in sedimentary rock laid down 65 million years ago as evidence of a meteorite impact at that time.

If scientists find high iridium levels in material ejected long distances from the newly found crater, it will be the first verification of what such levels mean, Robertson said.

Scientists can also see if the fossil record corresponding to the time that material settled shows evidence of extinctions, he said.

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