Saturday, February 16, 2013

New timing data for the K-Pg boundary event

Teams from the Berkeley Geochronology Center (BGC), the University of California, Berkeley, and universities in the Netherlands and the United Kingdom, have come up with new evidence that the most famous of all the extinction events, because it wiped out the dinosaurs, the K-Pg extinction was caused by an asteroid impact; or at least the final stage of the extinction event was accompanied by an impact.

The research team had noticed that none of the existing dates seemed to match, and the method used wasn't as accurate as it could be, so before attempting to date the impact they re-calibrated and revamped the existing 40Ar/39Ar dating technique.

Using ash collected from the Hell Creek Formation in Montana and tektites from Haiti, the researchers have come up with the most precise date yet for the impact event, 66,038,000ma.

This date is, according to the team, accurate to within 11k years, and is the most precise date yet.

The team are quick to add that whilst there was an impact event accompanying the final stage of the K-Pg event, there was a decline in flora and fauna for over a million years before the impact. Climate variation, possibly from erupting flood basalt's (the Deccan traps) had caused dramatic changes in environmental conditions, leading to biological decline.

The team are also keen to date the Deccan Traps, and it is expected that the new dates will be gathered in the near future.


Image; Artists impression of an asteroid impacting the Earth. revers_jr / Fotolia

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