In the interest of providing this information to all list members, I'd like to forward this message that I received from Dr. A.Y. Glikson tonight. Thank you Dr Glikson Sincerely, Bernd Pauli
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- To: <bernd.pauli@lehrer1.rz.uni-karlsruhe.de>
- Subject: Origin of the KT extinction
- From: "Dr A.Y. Glikson" <aygsearch@cos.com.au>
- Date: Tue, 29 Sep 1998 23:38:58 +1000
Dear Bernd Pauli, With reference to your contribution to Benny Peiser's bulletin, since 1988 Lyn Sutherland has written an up-to-date review of the K-T extinction, in the 1996 AGSO Journal vol. 16 part 4 - in which he accepts the evidence for meteoritic impact. You may like to refer to a recent abstract in Meteoritics and Planetary Science, 1998, vol. 33, No. 4 - "Chromium in the Cretaceous-Tertiary boundary layer: first isotopic evidence for an impactor and its type" by Shukolyukov and Lugmair - presenting evidence for meteoritic 53Cr/52Cr on the boundary. Along with unique trevorite-rich quench Ni spinels in condensate spherules, shocked quartz with PDF lamella, microdiamonds, chondritic Pd/Ir ratios, 3/4 He anomalies etc. etc. - not to mention the Chicxulub crater itself - this leaves little doubt regarding the impact. The connection between the extinction and the Deccan traps is contentious, as volcanism appears to have been triggered a few hundred thousand years prior to the KT boundary, if the isotopic data are accurate. The possibility of a double impactite layer and multiple impacts related to cometary shower - analogous to those indicated along the J-K and E-O boundaries - remains likely but yet unproven. Respectfully, Andrew Glikson Research School of Earth Science, Australian National University, Canberra, ACT 0200 andrew.glikson@anu.edu.au 29 September, 1998
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