Econintersect: The Chicxulub crater shared between the northern end of the Yucatan peninsula and the Gulf of Mexico is generally believed to mark the impact point of a massive asteroid or comet about 65 million years ago. The timing of this impact has been associated within measurement error to have coincided with the mass extinction of plant and animal life on earth, including wiping out the dinosaurs. This time has been identified in geologic terms as the Cretaceous-Paleogene (K-Pg) boundary or the Cretaceous-Tertiary (K-T) boundary.
Click on graphic for full geologic timeline at EnchantedLearning.com.
There have been scientists who have argued that other factors may have been involved in the K-Pg extinction, such as unusually active volcanic eruptions, abrupt climate change and/or sea level change (Wikipedia). This Video of the Week presents a 47 minute summary of the studies that indicate the impact that created the Chicxulub crater was the singular most imporant factor in the mass extinction of 75% of the life on earth 65 million years ago.
Hat tip to Roger Erickson.
References:
- Dinosaur extinction link to crater confirmed (Paul Rincon, BBC News, 04 March 2010)
- Dinosaurs Went Extinct Almost Immediately After Mexican Asteroid Strike (George Dvorsky, We come from the future, 08 February 2013)
- Chicxulub crater (Wikipedia)
- Cretaceous–Paleogene extinction event (Wikipedia)
- The History of 35,000 Meteorites (GEI News, 16 July 2013)
- Mapping Over 1,400 Armageddons (GEI News, 12 August 2013)
- Geologic Time Scale (EnchantedLearning.com)