Does the plankton record agree that a meteor caused the Cretaceous/Tertiary mass extinction?
The plankton record doesn’t lie. And again it is showing that the meteor that created the Chicxulub impact crater in Mexico didn’t cause the Cretaceous/Tertiary [KT] mass extinction, says Gerta Keller – the Princeton University paleontologist whose group has been a primary questioner of the widely accepted theory that the asteroid wiped out the dinosaurs and most life 65 million years ago. As researchers were wrapping up last week’s European Geosciences Union meeting in Vienna, Austria, the Keller group is publishing an article April 27 online in the Journal of the Geological Society, London, [JGSL 166, 393-411 2009 doi: 10.1144/0016-76492008-116] on its latest data in support of its view that the impact occurred 300,000 years before the KT mass extinction. Keller’s work also is among research discussed last weekend at a post-EGU workshop on Austrian geological sections of the KT. The article focuses on stratigraphy in northeastern Mexico, in particular a site called El Penon outside M
Three-dimensional seismic images of a crater believed to be formed when an asteroid stuck the Earth 65 million years ago, causing the extinction of dinosaurs, suggest that the object landed in deeper water, leading to a bigger splash than previously assumed. The 3D images are of the Chicxulub crater, a mostly submerged and buried impact crater on the Mexico coast, which was formed when an asteroid struck on the coast of the Yucatan Peninsula. Most scientists agree the impact played a major role in the KT Extinction Event that caused the extinction of most life on Earth, including the dinosaurs. According to Sean Gulick, a research scientist at the Institute for Geophysics at The University of Texas and principal investigator for the project, the new images reveal the asteroid landed in deeper water than previously assumed and therefore released about 6.5 times more water vapor into the atmosphere. The impact site also contained sulfur-rich sediments called evaporites, which would have
Almost all the large vertebrates on Earth, on land, at sea, and in the air (all dinosaurs, plesiosaurs, mosasaurs, and pterosaurs) suddenly became extinct about 65 Ma, at the end of the Cretaceous Period. At the same time, most plankton and many tropical invertebrates, especially reef-dwellers, became extinct, and many land plants were severely affected. This extinction event marks a major boundary in Earth’s history, the K-T or Cretaceous-Tertiary boundary, and the end of the Mesozoic Era. The K-T extinctions were worldwide, affecting all the major continents and oceans. There are still arguments about just how short the event was. It was certainly sudden in geological terms and may have been catastrophic by anyone’s standards. Despite the scale of the extinctions, however, we must not be trapped into thinking that the K-T boundary marked a disaster for all living things. Most groups of organisms survived. Insects, mammals, birds, and flowering plants on land, and fishes, corals, and
The plankton record doesn’t lie. And again it is showing that the meteor that created the Chicxulub impact crater in Mexico didn’t cause the Cretaceous/Tertiary [KT] mass extinction, says Gerta Keller – the Princeton University paleontologist whose group has been a primary questioner of the widely accepted theory that the asteroid wiped out the dinosaurs and most life 65 million years ago. As researchers were wrapping up last week’s European Geosciences Union meeting in Vienna, Austria, the Keller group is publishing an article April 27 online in the Journal of the Geological Society, London, [JGSL 166, 393-411 2009 doi: 10.1144/0016-76492008-116] on its latest data in support of its view that the impact occurred 300,000 years before the KT mass extinction. Keller’s work also is among research discussed last weekend at a post-EGU workshop on Austrian geological sections of the KT. The article focuses on stratigraphy in northeastern Mexico, in particular a site called El Penon outside M
Three-dimensional seismic images of a crater believed to be formed when an asteroid stuck the Earth 65 million years ago, causing the extinction of dinosaurs, suggest that the object landed in deeper water, leading to a bigger splash than previously assumed. The 3D images are of the Chicxulub crater, a mostly submerged and buried impact crater on the Mexico coast, which was formed when an asteroid struck on the coast of the Yucatan Peninsula. Most scientists agree the impact played a major role in the KT Extinction Event that caused the extinction of most life on Earth, including the dinosaurs. According to Sean Gulick, a research scientist at the Institute for Geophysics at The University of Texas and principal investigator for the project, the new images reveal the asteroid landed in deeper water than previously assumed and therefore released about 6.5 times more water vapor into the atmosphere. The impact site also contained sulfur-rich sediments called evaporites, which would have
