Word: impact
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...controversial paper was written by geoscientists Gerta Keller of Princeton University and Thierry Addate of the University of Lausanne, in Switzerland. Both researchers knew that challenging the impact doctrine would not be easy. The asteroid charged with killing the dinosaurs, after all, left more than the Chicxulub crater as its calling card. At the same 65-million-year depth, the geologic record reveals that a thin layer of iridium was deposited pretty much everywhere in the world. Iridium is an element that's rare on Earth but common in asteroids, and a fine global dusting of the stuff is precisely...
...Keller and Addate worried that we were misreading both the geologic and fossil records. They conducted surveys at numerous sites in Mexico, including a spot called El Peñón, near the impact crater. They were especially interested in a 30-ft. layer of sediment just above the iridium layer. That sediment, they calculate, was laid down at a rate of about 0.8 in. to 1.2 in. per thousand years, meaning that all 30 feet took 300,000 years to settle into place...
...mass extinction level can be seen above this interval," Keller says. "Not a single species went extinct as a result of the Chicxulub impact...
...digs were so close to ground zero, the immediate species loss ought to be have been - if anything - greater there than anywhere else in the world. Instead, the animals seemed to escape unharmed. Other paleontologists, however, believe that the very proximity of El Peñón to the impact site makes the results even less reliable. Earthquakes and tsunamis that resulted from the collision could have wrought havoc on the sedimentary record, causing discrete strata to swirl together and completely scrambling time lines. Keller disagrees, pointing out that the slow accretion of sediment that she and Addate recorded...
...believe we will find a cure, and I hope it will be soon. In a way, it's not about me necessarily getting better. I think that the idea behind any kind of service is that you hope that its impact will outlive you anyway, whether it happens in your lifetime or after. The fact that it happened at all is terrific. If it had something to do with your efforts, great...