A volcanic eruption
Abstract
It is argued that a massive volcanic eruption, and not an extraterrestrial impact, may have killed most species of life over 65 million years ago, and evidence is presented that boundary clay at the time of mass extinction was deposited in less than one year (as expected from impact) rather than in 10,000 yrs (as expected from an extended period of volcanism). Magnetic and fossil studies of the Deccan Traps in India indicate that these basaltic lava flows were laid down at the KT boundary. A comparative study is conducted of normal- and reversed-magnetized basaltic lava crystals of iron-titanium oxides. It is concluded that a causal relation exists between the behavior of the earth's core, where the magnetic field is generated, and mass extinctions.
- Publication:
-
Scientific American
- Pub Date:
- October 1990
- DOI:
- 10.1038/scientificamerican1090-85
- Bibcode:
- 1990SciAm.263d..85C
- Keywords:
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- Extinction;
- Paleobiology;
- Volcanoes;
- Biological Evolution;
- Fossils;
- Geochronology;
- Geomagnetism;
- Lava;
- Geophysics