What caused the mass extinction An extraterrestrial impact

Journal Article · Mon Oct 01 00:00:00 EDT 1990 · Scientific American; (United States)

DOI:https://doi.org/10.1038/scientificamerican1090-78· OSTI ID:5316291

Alvarez, W ^[1]; Asaro, F ^[2]

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1. Univ. of California, Berkeley (USA)
2. Lawrence Berkeley Laboratory, CA (USA)

The authors and other investigators discovered iridium in the clays that mark the sudden disappearance of dinosaurs from the fossil record. Because iridium is rare in the earth's crust but abundant in some meteorites, they concluded that a giant meteorite collided with the earth, hurling megatons of debris into the atmosphere. This paper describes and discusses the accumulating evidence that suggests an asteroid or comet caused the Cretaceous extinction.

• OSTI ID: 5316291
• Journal Information: Scientific American; (United States), Journal Name: Scientific American; (United States) Vol. 263:4; ISSN SCAMA; ISSN 0036-8733
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ANIMALS
BIOLOGICAL EXTINCTION
BOUNDARY CONDITIONS
CENOZOIC ERA
CHALCOGENIDES
CONTINENTAL CRUST
CRETACEOUS PERIOD
CRYSTAL STRUCTURE
EARTH CRUST
ECOLOGICAL CONCENTRATION
ELEMENTS
FOSSILS
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC SURVEYS
IMPACT SHOCK
IRIDIUM
LAYERS
MESOZOIC ERA
METALS
METEORITES
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
QUARTZ
SILICON COMPOUNDS
SILICON OXIDES
SURVEYS
TERTIARY PERIOD
TRANSITION ELEMENTS