MUFONET-BBS Network - Mutual UFO Network NEWS

Master Index Current Directory Index Go to SkepticTank Go to Human Rights activist Keith Henson Go to Scientology cult

Skeptic Tank!

MUFONET-BBS Network - Mutual UFO Network ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NEWS-WIRE ~~~~~~~~~~~ 旼컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴커 =START= XMT: 08:21 Thu Feb 07 EXP: 08:00 Thu Feb 14 쿞TUDY SUPPORTS THEORY THAT ASTEROID IMPACT TRIGGERED 쿐XTINCTION OF DINOSAURS 쿥ASHINGTON (FEB. 7) UPI - Glass fragments from Haiti provide 퀃he strongest evidence yet that an asteroid impact may have 퀃riggered the extinction of dinosaurs, advocates of the 쿬ontroversial theory said. 쿓owever, opponents who claim that it is not necessary to 쿹ook to space to explain the mysterious demise of the 쿭inosaurs said they were unswayed by the latest results 퀁eleased Wednesday. 쿟he debate over what wiped out the dinosaurs and many other 쿹ife forms at the end of the Cretaceous period, about 66 쿺illion years ago, has been raging since 1980, when Nobel 쿹aureate Luis Alvarez and his son Walter Alvarez rocked the 퀂cientific world by proposing that the mass extinction was 쿬aused by a huge asteroid or comet slamming into Earth 쿚ther scientists argued that Earth-bound forces like 퀆olcanoes could account for the extinction, and that fossil 쿮vidence showed the dying off of dinosaurs and other life 쿯orms spanned about 100,000 years - a relatively short 쿾eriod in geological terms, but far longer than the effects 쿽f an asteroid impact would likely have lasted. 쿔n recent years, supporters of the Alvarez theory have been 쿪massing evidence to suggest the ''killer'' asteroid may 쿴ave landed on Mexico's Yucatan Peninsula, creating the 쿺assive Chlexulub crater. 쿙ow, researchers say chemical analysis of tiny pieces of 쿻atural glass found in Haitian sediments dating back about 66 million years show the fragments had characteristics of 쿲lass formed when a large asteroid or comet hits Earth. 쿑urthermore, the fragments are nearly free of the crystals 쿪nd gas or water bubbles found in glass produced by a 퀆olcanic eruption, the team from University of Rhode Island, 쿢niversity of Michigan, University of North Carolina and 쿢niversity of Florida-Gainesville reported in the journal 쿙ature. ''It is virtually impossible to create glass from a volcanic 쿮xplosion that is free of gas. Any volcanic explosion is 쿭riven by gas,'' said Jan Smit of the Free University in 쿌msterdam, who is currently at the University of California- 쿍erkeley. ''This is the conclusive piece of evidence (for a cosmic 쿶mpact at the time of dinosaur extinction). It is just what 퀇e needed,'' said Smit, a staunch supporter of the 쿮xtraterrestrial theory of mass extinction. 쿥alter Alvarez, a geology professor at University of 쿎alifornia- Berkeley, said the glass results represent ''a 퀃remendously important development'' in support of his 퀃heory. ''My guess is this will clinch it for some people 퀇ho have been sitting on the fence,'' he said. 쿓owever, Alvarez and Smit cautioned that the findings only 퀂erve to place an asteroid impact and dinosaur extinction in 퀃he same time frame, and the crucial question of how a 쿬osmic crash could have caused widescale die-offs of plant 쿪nd animal life remains unanswered. ''It could be darkness, forest fires, heat, methane gas from 쿭ecaying life... It could be almost anything,'' said Smit, 퀇ho commented on the new findings in an accompanying 쿮ditorial. 쿎huck Officer, a research professor of earth sciences at 쿏artmouth University in Hanover, N.H., termed the 쿬onclusions of the latest study ''nonsense.'' 쿚fficer said he thinks volcanoes played a major role in the 쿮xtinction of dinosaurs, noting the most intense volcanic 쿪ctivity that Earth has known took place during the end of 퀃he Cretaceous and beginning of the Tertiary periods. 쿟he researcher, who has also examined the Haitian deposit, 쿻oted at least four layers of glass particles are found at 퀃he site - two layers of which are located about 13 feet 쿴igher than the fragments in the Nature study, indicating 퀃hey were deposited at a considerably later date. 쿟hose multiple layers are consistent with the sediment 쿾attern from repeated volcanic eruptions, Officer said, 쿪dding that it would be highly unlikely asteroids would 퀂trike the same area four times. 쿟he Dartmouth scientist agreed the Haitian glass displays 퀂ome puzzling chemical features, such as high levels of 쿬alcium. But he also noted that volcanic glass has been 쿯ound that contains very little gas or water, and that a few 쿬rystals characteristic of volcanic glass have also been 쿯ound at the site. ''What we have seen in the deposits is all conformable with 퀆olcanic origins '' he said. =END=


E-Mail Fredric L. Rice / The Skeptic Tank