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Science 6 June 1980:
Vol. 208. no. 4448, pp. 1095 - 1108
DOI: 10.1126/science.208.4448.1095
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Articles

Extraterrestrial Cause for the Cretaceous-Tertiary Extinction

Luis W. Alvarez 1, Walter Alvarez 2, Frank Asaro 3, and Helen V. Michel 4

1 Professor emeritus of physics at Lawrence Berkeley Laboratory, University of California, Berkeley 94720
2 Associate professor in the Department of Geology and Geophysics, University of California, Berkeley
3 Senior scientist in the Energy and Environment Division of Lawrence Berkeley Laboratory
4 Staff scientist in the Energy and Environment Division of Lawrence Berkeley Laboratory

Platinum metals are depleted in the earth's crust relative to their cosmic abundance; concentrations of these elements in deep-sea sediments may thus indicate influxes of extraterrestrial material. Deep-sea limestones exposed in Italy, Denmark, and New Zealand show iridium increases of about 30, 160, and 20 times, respectively, above the background level at precisely the time of the Cretaceous-Tertiary extinctions, 65 million years ago. Reasons are given to indicate that this iridium is of extraterrestrial origin, but did not come from a nearby supernova. A hypothesis is suggested which accounts for the extinctions and the iridium observations. Impact of a large earth-crossing asteroid would inject about 60 times the object's mass into the atmosphere as pulverized rock; a fraction of this dust would stay in the stratosphere for several years and be distributed worldwide. The resulting darkness would suppress photosynthesis, and the expected biological consequences match quite closely the extinctions observed in the paleontological record. One prediction of this hypothesis has been verified: the chemical composition of the boundary clay, which is thought to come from the stratospheric dust, is markedly different from that of clay mixed with the Cretaceous and Tertiary limestones, which are chemically similar to each other. Four different independent estimates of the diameter of the asteroid give values that lie in the range 10 ± 4 kilometers.


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   Abstract »    Full Text »    PDF »
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   Full Text »    PDF »
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   Abstract »    PDF »
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   Abstract »    PDF »
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   Abstract »    PDF »
Trace fossils in the aftermath of mass extinction events.
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   Abstract »    PDF »
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   Abstract »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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PNAS 99, 7836-7840
   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
Impact dust not the cause of the Cretaceous-Tertiary mass extinction.
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   Abstract »    Full Text »    PDF »
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U. B. Marvin (2002)
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   Abstract »    PDF »
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Eugen and I. Seibold (2002)
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   Abstract »    PDF »
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   Abstract »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
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   Abstract »    Full Text »    PDF »
Episodicity during orogenesis.
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   Abstract »    PDF »
Geochemistry of the Cretaceous-Tertiary boundary at Blake Nose (ODP Leg 171B).
F. Martinez-Ruiz, M. Ortega-Huertas, D. Kroon, J. Smit, I. Palomo-Delgado, and R. Rocchia (2001)
Geological Society, London, Special Publications 183, 131-148
   Abstract »    PDF »
Dinosaur abundance was not declining in a "3 m gap" at the top of the Hell Creek Formation, Montana and North Dakota: Comment and Reply: COMMENT.
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Geology 28, 1150
   Full Text »    PDF »
Carbon Isotope Excursion in Atmospheric CO2 at the Cretaceous-Tertiary Boundary: Evidence from Terrestrial Sediments.
(2000)
Palaios 15, 314-322
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P. M. Sheehan, D. E. Fastovsky, C. Barreto, and R. G. Hoffmann (2000)
Geology 28, 523-526
   Abstract »    Full Text »    PDF »
Cretaceous age for Ir-rich Deccan intertrappean deposits: palaeontological evidence from Anjar, western India.
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   Abstract »    Full Text »    PDF »


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