The kinetic energy created by asteroid and comet impacts with the Earth may be key to linking some impacts with mass extinction events. Michael Lucas, a geology student at Florida Gulf Coast University, believes that the severity of four extinction events during the Mesozoic and Cenozoic can be correlated with the total kinetic energy released by impacts that occur during the geologic age of the mass extinction.

Lucas will present his findings April 4 at the Geological Society of America’s North-Central Section and Southeastern Section Joint Meeting in Lexington, Kentucky.

Lucas analyzed the kinetic energy released by 31 of the largest impact structures from the last 248 million years and correlated them with the Norian, Tithonian, Late Eocene, and K-T extinction events. The impact energy released during the geologic ages of each extinction event is at least 10 million megatons of TNT equivalent yield per geologic age. Lucas believes that this could represent a minimum impact energy required to cause a global-scale mass extinction. His research results also reveal that synchronous multiple impact events could also have caused extinctions.

ìApproximately ten percent of the impact structures on Earth are doublets or twin structures, suggesting a nearly simultaneous impact of binary asteroids or fragmented comets,î he said. An example of a twin impact structure would be the Kara / Ust-Kara twin impact structure in Russia which is about 73 million years old.

By Kara LeBeau, GSA Staff Writer

Contact information:

Michael P. Lucas
College of Arts & Sciences
Florida Gulf Coast University
10501 FGCU Blvd. South
Ft. Myers FL 33965 USA
E-mail: mlucas@fgcu.edu
Phone: 941-590-7225

Abstract available at:
http://gsa.confex.com/gsa/2002NC/finalprogram/abstract_32110.htm

Geological Society of America
Southeastern Section and North-Central Section Joint Meeting
April 3-5, 2002
Hyatt Regency Hotel and Lexington Civic Center
Lexington, KY

For information and assistance during the meeting, please see the media assistant at the GSA registration table or call 859-253-1234.

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Geological Society of America
Release No. 02-19
Contact: Ann Cairns
303-357-1056
acairns@geosociety.org