Impact Event - Pleistocene Impact Events

Pleistocene Impact Events

In addition to the extremely large impacts that happen every few tens of millions of years, there are many smaller impacts that occur more frequently but which leave correspondingly smaller traces behind. Due to the strong forces of erosion at work on Earth, only relatively recent examples of these smaller impacts are known.

Artifacts recovered with tektites from the 803,000 year-old Australasian strewnfield event in Asia link a Homo Erectus population to a significant meteorite impact and its aftermath.

• the Rio Cuarto craters in Argentina, produced by an asteroid striking Earth at a very low angle, ~10,000 years old.
• the Lonar crater lake in India, which now has a flourishing semi-tropical jungle around it, ~52,000 years old (though a study published in 2010 gives a much greater age).
• the Henbury craters in Australia (~5,000 years old), and Kaali craters in Estonia (~2,700 years old), apparently produced by objects which broke up before impact.

The Younger Dryas impact event is a discredited hypothesis that an air burst from a purported comet above or even into the Laurentide Ice Sheet north of the Great Lakes set all of the North American continent ablaze around 12,900 years ago. The hypothesis attempts to explain the extinction of many of the large animals in North America and the unproven population decreases in the North American stone age Clovis culture about at the end of the Pleistocene epoch. Proponents claim the existence of a charred carbon-rich layer of soil found at some 50 Clovis-age sites across the continent. It has been criticized for not being consistent with paleoindian population estimates. Impact specialists have studied the claim and concluded that there never was such an impact, in particular because various physical signs of such an impact cannot be found.