New clues to 2bn-year-old murder
Mood:
Deeply impacted
Read/Post Comments (0)
http://www.guardian.co.uk/international/story/0,3604,1216444,00.html
New clues to 2bn-year-old murder
Tim Radford, science editor
Friday May 14, 2004
The Guardian
Scientists believe they are on the track of the biggest mass murderer in the two-billion year history of life. A buried crater off Australia could be the first direct evidence of a celestial assassin that wiped out more than 80% of life on Earth 250m years ago.
Luann Becker, of the University of California, Santa Barbara, reports in Science online today on extensive evidence for a 125-mile wide crater called Bedout off the northwestern coast of Australia. The clues match the date of an event known to palaeontologists as the "great dying" - the spectacular mass extinction at the end of the Permian era, when 80% of all terrestrial creatures, and 95% of all marine life, were wiped out.
For decades researchers have argued about whether the damage was done by volcanism, climate change, glaciation, or a comet or asteroid. For the first time, there is evidence of a direct hit from a cosmic projectile.
While working in Antarctica, Dr Becker and colleagues found meteor fragments in sediment formed at the end of the Permian. But they also found something even more telling: fragments of "shocked quartz" - evidence of violently altered terrestrial rock - in Antarctica and Australia in the same stratum. At the time, Australia, Antarctica, Africa and the Americas were part of a huge supercontinent called Pangea.
(More at site...)
(Thanks to the Forteana list!)
New clues to 2bn-year-old murder
Tim Radford, science editor
Friday May 14, 2004
The Guardian
Scientists believe they are on the track of the biggest mass murderer in the two-billion year history of life. A buried crater off Australia could be the first direct evidence of a celestial assassin that wiped out more than 80% of life on Earth 250m years ago.
Luann Becker, of the University of California, Santa Barbara, reports in Science online today on extensive evidence for a 125-mile wide crater called Bedout off the northwestern coast of Australia. The clues match the date of an event known to palaeontologists as the "great dying" - the spectacular mass extinction at the end of the Permian era, when 80% of all terrestrial creatures, and 95% of all marine life, were wiped out.
For decades researchers have argued about whether the damage was done by volcanism, climate change, glaciation, or a comet or asteroid. For the first time, there is evidence of a direct hit from a cosmic projectile.
While working in Antarctica, Dr Becker and colleagues found meteor fragments in sediment formed at the end of the Permian. But they also found something even more telling: fragments of "shocked quartz" - evidence of violently altered terrestrial rock - in Antarctica and Australia in the same stratum. At the time, Australia, Antarctica, Africa and the Americas were part of a huge supercontinent called Pangea.
(More at site...)
(Thanks to the Forteana list!)
Read/Post Comments (0)
Previous Entry :: Next Entry
Back to Top
