Dinosaur Extinction
Theory 'A Myth'

By Roger Highfield
Science Editor
The Telegraph - UK

The popular belief that a vast crater near Mexico is the scar left by an asteroid which wiped out dinosaurs 65 million years ago is questioned today. Fantasy Golf
The Chicxulub crater on the Yucatan Peninsula led many scientists to conclude that fast-moving debris from the asteroid's impact would have superheated the atmosphere so that vegetation burst into flames over much of the planet.
According to this theory, ground temperatures soared to about 1,000C, igniting forest fires across the world and boiling land organisms alive. The soot and smoke thrown into the atmosphere may have helped block sunlight, causing global cooling and plunging the planet into winter.
But a study published today in the Proceedings of the National Academy of Sciences, by Dr Gerta Keller of Princeton University, Dr Thierry Adatte from the University of Neuchatel and Dr Wolfgang Stinnesbeck from the University of Karlsruhe, suggests the crater predates the mass extinction by 300,000 years.
Their conclusion came after they studied strata in a core drilled from the crater.
The team suggests a more complex series of events such as an additional asteroid impact, perhaps in the Shiva Crater in India, volcanism, and climate change.
© Copyright of Telegraph Group Limited 2004.



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