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Wits scientists
discover fossil meteorite
A fossil meteorite has been discovered in
the Kalahari Desert by University of the Witwatersrand
(Wits) scientists, it was announced on Wednesday.
"We are excited about this discovery because it challenges
the conventional wisdom about the nature of the meteorite
impact process," said Wits School of Geosciences researcher,
Professor Lew Ashwal.
The 25cm meteorite was found in a 145-million-year-old
Morokweng crater, 766 metres beneath the Kalahari Desert in
North-West, he said in a media statement.
A scientific research paper confirming the find was
published this week in the international science journal
Nature.
| 'Meteorites
simply vaporise' |
Chemical and
mineral data confirmed the meteorite was a fragment of the
original five-to-ten-kilometre asteroid that formed
Morokweng's 70km-diameter crater at the Jurassic-Cretaceous
boundary - home to the first complete fossil stony
meteorites found in an impact melt.
The chemical composition of the latest find differed from
that of previous discoveries, said Ashwal.
"This discovery is significant because it means that the
original asteroid made it through the atmosphere and
impacted with the surface of the earth and survived the
intense heat it created.
"In most cases, meteorites simply vaporise when they reach
the atmosphere," he said.
The discovery could suggest previous models for the
evolution of the projectile during impact were incomplete
and it supported the assumption that the identity of a large
impactor could be inferred, said Ashwal.
"There is also no doubt that the discovery will help us to
better understand meteorite impacts," he said. - Sapa
Published on the Web by IOL on
2006-05-17 11:35:35
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