Definition of Alvarez theory
: a theory in paleontology: the majority of dinosaurs were rendered extinct at the end of the Cretaceous period by the effects (such as volcanic activity, fires, intensely acidic rain, and the blocking of sunlight) of a giant asteroid impacting the earth Then geologists traced the ghostly outlines of the buried Chicxulub crater, and the Alvarez theory became so widely accepted that the menace of death from above is now part of popular lore. — Timothy Ferris, New York Times, 25 May 1997 The Alvarez theory is based on the fact that there is a worldwide geologic layer of iridium deposited at about the same time that fossil records show extinction of the dinosaurs and many other animal species. — Toronto Star, 14 June 1991 Many other scientists—especially traditional geologists and paleontologists—greeted the Alvarez hypothesis with great skepticism, sometimes with open derision. — Robert C. Cowen, Christian Science Monitor, 20 June 1989
Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Origin and Etymology of alvarez theory
after Luis W. Alvarez †1988 U.S. physicist & his son Walter Alvarez *1940 U.S. geologist, who were among coauthors of the hypothesis in 1980
First Known Use: 1980See Words from the same year
Seen and Heard
What made you want to look up Alvarez theory? Please tell us where you read or heard it (including the quote, if possible).