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Was it an asteroid crash that wiped out the dinosaurs?
© AMNH |
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Rare in the Earth’s crust, iridium is far more common in some kinds of asteroids. This theory captured the imagination of both scientists and the public, sparking an explosion of research into the causes of major mass extinctions.
Further evidence came along in the form of quartz grains with unusual fractures, from formations at the Cretaceous-Tertiary boundary. This damage could only have occurred under conditions of extreme heat and pressure, both of which would have been generated by an asteroid impact. But where had it landed?
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