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Article: Signs of an ancient worldwide wallop. (new evidence suggests mass extinction caused by extraterrestrial body that struck earth)
- Article from:
- Science News
- Article date:
- March 4, 1989
- Author:
CopyrightCOPYRIGHT 1989 Science Service, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Signs of an ancient worldwide wallop
Years, perhaps decades, will pass before scientists agree on a basic theory to explain why a vast number of species went extinct some 66 million years ago. Now entering the debate is one more piece of evidence suggesting an extraterrestrial body hit the Earth at that time, which is known as the Cretaceous-Tertiary (K-T) boundary.
John McHone and his colleagues at Arizona State University in Tempe report in the March 3 SCIENCE that they have detected a mineral called stishovite in samples collected from the K-T boundary at Raton, N.M. McHone says natural stishovite has not been found anywhere on Earth except at sites ...