RE: Source of KT asteroid pdf

["Thomas R. Holtz, Jr." <tholtz@umd.edu>]

> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] 
> On Behalf Of David Marjanovic
> Sent: Saturday, April 19, 2008 5:55 AM
> To: DML
> Subject: Re: Source of KT asteroid pdf
> 
> > PS Isn't there stronger evidence for volcanism playing a 
> role in the 
> > K/T extinction now? I remember a science story about the 
> timing of a 
> > flood basalt province or some such.
> 
> To the contrary. The timing is off.
> http://dml.cmnh.org/2003Dec/msg00092.html

Whoa there!!  While it is true that the the timing is way off for the
Chicxulub impactor to be the cause of the Deccan Traps, that doesn't mean
that degassing from Deccan Traps had no role in the extinction.

In particular, some extinction models show that disruptions of habitats from
previous phenomena are necessary to produce more severe mass extinctions. So
the role of Deccan may have been to shake things up (esp. in the marine
realm), allowing the killing blow of the impact to be even more extreme.

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Earth, Life & Time Program, College Park Scholars
http://www.geol.umd.edu/~jmerck/eltsite/
Fax: 301-405-0796

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA