. 24/7 Space News .
New Clovis-Age Comet Impact Theory

Missing in the new theory is a crater marking an impact, but researchers argue that a strike above or into the Laurentide ice sheet could have absorbed it since it was less intense than the K-T event.
by Staff Writers
Eugene, OR (SPX) May 23, 2007
Two University of Oregon researchers are on a multi-institutional 26-member team proposing a startling new theory: that an extraterrestrial impact, possibly a comet, set off a 1,000-year-long cold spell and wiped out or fragmented the prehistoric Clovis culture and a variety of animal genera across North America almost 13,000 years ago.

Driving the theory is a carbon-rich layer of soil that has been found, but not definitively explained, at some 50 Clovis-age sites in North America that date to the onset of a cooling period known as the Younger Dryas Event. The sites include several on the Channel Islands off California where UO archaeologists Douglas J. Kennett and Jon M. Erlandson have conducted research.

The theory is being discussed publicly, for the first time, Wednesday, May 23, at the 2007 Joint Assembly of the American Geophysical Union in Acapulco, Mexico. Kennett is among the attendees who will be available to discuss the theory with their peers. The British journal Nature first addressed the theory in a news-section story in its May 18 issue.

Before today, members of the team - including Kennett's father, James P. Kennett of the University of California, Santa Barbara, and Richard B. Firestone of Lawrence Berkeley National Laboratory - had been quietly introducing the theory to their professional colleagues.

Douglas Kennett, with Erlandson watching, detailed the theory May 19 to a fully packed UO classroom, where students and faculty members from archaeology, art history, anthropology, biology, geology, geography, political science and psychology, pelted Kennett with questions.

The researchers propose that a known reversal in the world's ocean currents and associated rapid global cooling, which some scientists blame for the extinction of multiple species of animals and the end of the Clovis Period, was itself the result of a bigger event. While generally accepted theory says glacial melting from the North American interior caused the shift in currents, the new proposal points to a large extraterrestrial object exploding above or even into the Laurentide Ice Sheet north of the Great Lakes.

"Highest concentrations of extraterrestrial impact materials occur in the Great Lakes area and spread out from there," Kennett said. "It would have had major effects on humans. Immediate effects would have been in the North and East, producing shockwaves, heat, flooding, wildfires, and a reduction and fragmentation of the human population."

The carbon-rich layer contains metallic microspherules, iridium, carbon spherules, fullerenes, charcoal and soot. Some of those ingredients were found worldwide in soils dating to the K-T Boundary of 65 million years ago.

The K-T layer marks the end of the Cretaceous Period and the beginning of the Tertiary Period, when numerous species were wiped out after a massive asteroid is believed to have struck Mexico's Yucatan Peninsula and the Gulf of Mexico.

Missing in the new theory is a crater marking an impact, but researchers argue that a strike above or into the Laurentide ice sheet could have absorbed it since it was less intense than the K-T event.

Kennett said that 35 animal genera went extinct at the end of the Pleistocene, with at least 15 clearly being wiped out close to 12,900 years ago. There would have been major ecological shifts, driving Clovis survivors into isolated groups in search of food and warmth. There is evidence, he said, that pockets of Clovis people survived in refugia, especially in the western United States.

"This was a massive continental scale, if not global, event," Kennett said. He and Erlandson say that they are currently evaluating the existing Paleo-Indian archaeological datasets, which Kennett describes as "suggestive of significant population reduction and fragmentation, but additional work is necessary to test this hypothesis further."

Earlier research efforts need to be re-evaluated using new technologies that can narrow radiocarbon date ranges, and, as funding becomes available, new sites can be located and studied, Erlandson said.

"As we have grown more confident in the theory," Erlandson said, "we've been letting some of it out in informal talks to gage the response to see where we are headed and what the initial objections are, which will help us to maintain our own objectivity."

The interest in pursuing both old and new leads could ignite a major surge of interdisciplinary questioning and attract a new wave of interested students, Kennett and Erlandson said.

Email This Article

Related Links
University of Oregon
Asteroid and Comet Mission News, Science and Technology



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


Hayabusa Starts Fully Fledged Return Trip To Earth
Tokyo, Japan (SPX) Apr 29, 2007
Since February 2007, JAXA has been carefully preparing to start the fully fledged return trip to Earth using the ion engine and one attitude control reaction wheels (as two of the three wheels are unavailable due to anomalies.) The Hayabusa's return to the Earth is scheduled for June 2010.







  • Science Subcommittees Focus On Ensuring Health And Vitality Of NASA Workforce
  • Malaysian Astronauts Head To NASA For Training
  • Amid Turtles And Sharks, Astronauts Train For Lunar Mission
  • Using History To Design The Future

  • Seeking Mars Survival Secrets
  • Mars Rover Spirit Unearths Surprise Evidence Of Wetter Past
  • Breathtaking Views Of Deuteronilus Mensae On Mars
  • Seeking Mars Survival Secrets

  • Energia Posts 220 Percent Rise In 2006 Net Profit
  • Russia And ESA Sign Contract For Four Soyuz Launches From Kourou
  • Ariane 5 Achieves Record Performance With Geostationary Transfer Orbit
  • Ariane 5 Launches Twin GEO Birds

  • Tracking A Hot Spot In The Center Of The Biggest Ocean On Earth
  • MetOp-A Takes Up Service
  • General Dynamics Awarded Contract For NASA's Landsat Data Continuity Mission Study
  • ESA Presents The Sharpest Ever Satellite Map Of Earth

  • A Goofball Called Pluto
  • First Observation Of A Uranian Mutual Event
  • Continuing Our Jovian Journey
  • Rosetta And New Horizons Watch Jupiter In Joint Campaign

  • Gamma-Ray Bursts Active Longer Than Thought
  • Andromeda Way Will Make For A Nice Retirement Home For Our Sol
  • Baby Stars Hatching In Orion's Head
  • Johns Hopkins Team Finds Ring Of Dark Matter

  • Oresme Crater Show Many Signs Of The Early Lunar Heavy Bombardment
  • First China Mission To Moon To Launch By Year End
  • US Rejected Russian Request For Joint Moon Program
  • Longest Holiday In Space Ends As Russia Touts Lunar Tour Within Five Years

  • Putin Makes Glonass Navigation System Free For Customers
  • Hyper-Accurate Clocks - The Beating Heart Of Galileo
  • EU Sees Public Money Saving Galileo From Drifting Off Course
  • Germany Confident EU Will Take Over Galileo Project

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement