Re:Isotopic Evidence for the K-T Impactor and Its Type

I talked with the Dept. of Geology at the Univ. of SC last year and they are working on this issue with others. I believe they think the crater is at least 150km and likely larger. I haven't read the reference Gautam refers to but obviously there is dispute about the size. What are the issues to settle the matter?

Michael Teuton

-----Original Message-----
From: Larry Febo <larryf@capital.net>
To: dinosaur@usc.edu <dinosaur@usc.edu>
Date: Tuesday, November 17, 1998 9:48 AM
Subject: Re:Isotopic Evidence for the K-T Impactor and Its Type

Mon, Nov. 16, 1998 , Gautam Majumdar writes:

>Date: Mon, 16 Nov 1998 19:55:44 +0000
>From: Gautam Majumdar <gautam@majumdar.demon.co.uk>
>To: Dinosaur@usc.edu
>Subject: Re: Isotopic Evidence for the K - T Impactor and Its Type
>Message-ID: <TNhJYGAANIU2Ewjt@majumdar.demon.co.uk>

>Stanley Friesen <sarima@ix.netcom.com> wrote

>>And I
>>have certainly heard suggestions that at least one mid-Cenozoic crater is
>>known of comparable magnitude.
>>

>Recent work showed that the Chicxulub crater was about 100 km is diameter.
>The prominent 175-190 km feature is actually a fault scarp. Thus its size is
>comparable to both Popigai (100 km) and Chesapeake Bay (85 km) impact
>craters (both 35-36 mya) which were not associated with any extinction event.

>Morgan J, Warner M & The Chicxulub Working Group, Size and morphology
>of the Chicxulub impact crater, Nature 1997; 390: 472-76

>Melosh H J, Multi-ringed revelation, Nature 1997; 390: 439-40

>Stoffler D, Claeys P, Earth rocked by combination punch, Nature 1997; 388:
>331-32

>Kerr R A, Chesapeake Bay Impact Crater Confirmed, Science 1995; 269:
>1672

>Gautam Majumdar gautam@majumdar.demon.co.uk

PS, Don`t forget that other crater...the "Shiva Crater" mentioned by Chatterjee as a possible simultaneous impact (with the Chixalube). He gives it`s dimensions as 600 km long and 450km wide! (unless of course you want to "scale that down" a bit)?

Larry Febo.