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Asteroid Extinction Hypothesis

Dennis V. Kent

Title:
Asteroid Extinction Hypothesis
Author(s):
Kent, Dennis V.
Date:
Type:
Letters
Department:
Lamont-Doherty Earth Observatory
Volume:
211
Permanent URL:
Book/Journal Title:
Science
Abstract:
A distinguishing feature of the asteroid impact hypothesis presented by Alvarez et al. (6 June, p. 1095) for the end-of-Cretaceous biotic crisis is that it is based on direct physical evidence: the distribution of iridium in several Cretaceous-Tertiary sedimentary sections. I draw attention to other evidence which suggests that (i) a high Ir concentration may not be uniquely associated with an extraordinary extraterrestrial event and (ii) the impact of a large asteroid in any case is not likely to have had the dire consequences to life on the earth that they propose.
Subject(s):
Geochemistry
Publisher DOI:
http://dx.doi.org/10.1126/science.211.4483.648
Item views:
143
Metadata:
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