May 13, 2004 | David F. Coppedge

Another Impact Theory for Permian Extinction Proposed

Richard Kerr was very cautious in his announcement in Science1 about a new claim about an asteroid impact near Australia causing the Permian Extinction.  He went to lengths to point out that the evidence is not clear, and that many other scientists disagree.  After describing the “proposed” impact site, he cautioned:

Not so fast, say some researchers who specialize in deciphering signs of impact lingering in rock.  “There’s no convincing evidence for an impact origin” in the studied rocks, says impact petrographer Bevan French of the National Museum of Natural History in Washington, D.C.  “Everything they’re arguing was shocked [by impact] can have nonshock origins,” such as volcanic activity, he argues.  Despite the variety of evidence presented in this and two earlier Science papers by the same principal authors (Science, 21 November 2003, pp. 1388 and 1392), impact-triggered extinction at the P-T has yet to meet broad acceptance.

1Richard Kerr, “Evidence of Huge, Deadly Impact Found Off Australian Coast?” Science, Vol 304, Issue 5673, 941, 14 May 2004, [DOI: 10.1126/science.304.5673.941a].

That’s not the way it came across in the media.  On a Motorola pager, MSNBC trumpeted: “Scientists find suspect in ‘great dying’ impact – Scientists have linked Earth’s biggest extinction event, 250 million years ago, to a suspected impact crater off the coast of Australia.”
Freudianly, their next headline was about con artists.

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Categories: Fossils

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