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Re: Chicxulub's Antipode (Re: cause of death at KT)

Interesting discussion. The chances of finding a piece of ejecta that re-entered and survived the atmosphere must be a bit low. As I walk about the K/T boundary up here, I find lots of misc things but what exactly (besides a blob of glass altered to clay or perhaps a small crater in surrounding lamina) would I be looking for in a piece of re-entered material?

Frank (Cocky Avian Theropod) Bliss
MS Biostratigraphy
Weston, Wyoming

45.783664% of all statistics are made up at the time

On Sep 3, 2006, at 9:35 AM, Jeff Hecht wrote:

At 2:25 AM +0000 9/3/06, Phillip Bigelow wrote:
On Sat, 02 Sep 2006 22:12:53 -0700 (PDT) don ohmes <d_ohmes@yahoo.com>
At risk of getting on thin crust--

1). 65 my is old for deep ocean crust. Might be hard to find some
that was in the antipodal location at the time. Stuff can move fast,
like 10cm/a. That is 6500km since KT, IMMC. Might, in fact, be all

Regarding the sea floor around India, you might be right.  [I am a
neophyte when it comes to southern Asian tectonics].  But there are
numerous places in today's Pacific Ocean that still contain 65 my old
oceanic crust.

According to http://userpage.fu-berlin.de/~data/database/oceanage/ jgr_paper.html there is some Cretaceous sea-floor crust off the east coast of India and the west coast of Australia. The actual antipodes from the KT impact may have been subducted by now, but I would expect whatever splashed down to have been spread over a significant area. So there's hope for finding something, but it may take some work.

Jeff Hecht, science & technology writer
jeff@jeffhecht.com  http://www.jhecht.net
Boston Correspondent: New Scientist magazine
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