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), Vol. 263:4; ISSN 0036-8733
• Country of Publication: United States
• Language: English

Related Subjects

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