BOB HIRSHON (host):
A big bang in the Great White North. I’m Bob Hirshon and this is Science Update.
Mineral deposits in Indiana and Ohio may have come from a prehistoric comet explosion over Canada. Such an explosion was proposed by geophysicist Allen West to explain evidence of massive fires, followed by a quick climate change that killed off woolly mammoths and other mega-mammals. Now, University of Cincinnati anthropologist Ken Tankersley and his colleagues have traced fragments of a volcanic rock called kimberlite, which isn’t native to the area, to West’s proposed impact site in Canada.
KEN TANKERSLEY (University of Cincinnati):
It answered for me a major geological question: How did these kimberlite deposits reach southern Indiana and southern Ohio?
Tankersley says he thought that glaciers had transported them, until he discovered evidence that supports the more violent origin. I’m Bob Hirshon for AAAS, the Science Society.