Tag Archives: Alvarez Hypothesis

In 1981, Luis (left) and Walter Alvarez collected samples of layered sedimentary rocks in Gubbio, Italy, at the 65-million-year-old boundary between the Cretaceous (lower) and Paleogene (upper, formerly called Tertiary) geologic time periods.
1980: The Alvarez Hypothesis – Linking Asteroid Impact to Mass Extinction

The Alvarez Hypothesis suggests an asteroid impact caused the mass extinction at the K-Pg boundary, highlighted by the high iridium levels in Italian clay and the Chicxulub crater discovery