Jan Smit of the Free University in Amsterdam has been studying foraminifers
for years, and as a principal investigator on the Chicxulub Scientific Drilling
Program (CSDP), he performed extensive tests on the cores. He said in an interview
in November that Keller's "foraminifers" are not organic at all. They
are actually dolomite rhombs (minerals) that mimic foraminiferal testwalls
not a "stunning find," he said.
Dieter Stöffler, a planetary geoscientist from Humboldt University in Berlin and another CSDP principal investigator, also said in a November interview that even if Cretaceous microfossils were found in the crater core, he would not be surprised. When the Cretaceous sediments were lambasted with the extraterrestrial projectile, he explains, much of the sediments that were blown into the air would settle back into the crater. "Keller doesn't take that into consideration," he said.
Ward agrees, saying, "a more parsimonious explanation is that the so-called 'deep water deposits' were redeposited within weeks after the impact not 300,000 years." Although Keller is an expert in foraminifers, he says that in this case her conclusions are faulty. Additionally, he says, if there were multiple impact events, there should be impact debris deposits all over the world "and there are not."
Scientists studying Chicxulub and the mass extinction at the Cretaceous-Tertiary boundary admit that this is an acrimonious topic, the details of which are doubtful to be resolved any time soon.
"Unraveling the Chicxulub Case," Geotimes, January 2004
"Charcoal clues in dinosaur debate," Web Extra, Geotimes, January 2004
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