After a long period without decent dino news (my new painting by Doug Chaffee has arrived, btw) we’re now being treated to just scads of new theories, extinctions, and all sorts of feathered critters.
Did Dinos go extinct from a massive asteroid hit or from volcanism?
“…The cause of the dinosaurs’ demise is far from an open-and-shut case. Though many experts support the Chicxulub impact theory, some question whether the extinction was caused by an impact at all, and suggest that climate changes and volcanism were responsible. One line of reasoning holds that all three phenomena were to blame.
Gerta Keller, a geoscientist at Princeton University, found evidence for massive volcanic activity coinciding with the time of the extinction in an area called the Deccan Traps in India. Keller has advocated that this volcanism was the main culprit behind the dinosaurs’ downfall. Her idea has long been controversial and remains so. She is bluntly dubious of Chatterjee’s argument.
“We have worked extensively throughout India and investigated a number of the localities where Sankar Chatterjee claims to have evidence of a large impact he calls Shiva crater,” Keller wrote in an e-mail along with colleague Thierry Adatte of Switzerland’s Universite de Neuchâtel. “Unfortunately, we have found no evidence to support his claims… Sorry to say, this is all nonsense.”
Chatterjee cites a number of geologic features found near the Shiva site to suggest that it’s a crater, including shocked quartz known to be created during impacts, and iridium, an element found abundantly in meteorites and which is relatively rare in the Earth’s crust.
“These are the things which only can be found by impact,” Chatterjee told SPACE.com.
But Keller said each of these signals can be ascribed to causes other than a space rock impact. For example, the shocked quartz lacks the telltale signs denoting a high velocity impact shock, and the iridium dates from another time period than the KT era, she contends.
And though Chatterjee’s abstract was approved by conference organizers for the Geological Society of America meeting, this research has not been peer-reviewed in a scientific journal….”