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A meteor or comet impact near Quebec heaved a rain of hot melted rock along North America's Atlantic Coast about 12,900 years ago, a new study claims. Scientists have traced the geochemical signature of the BB-sized spherules that rained down back to their source, the 1.5-billion-year-old Quebecia terrane in northeastern Canada near the Gulf of Saint Lawrence. At the time of the impact, the region was covered by a continental ice sheet, like Antarctica and Greenland are today. Around this time, a global cooling began and the big animals in North America all vanished. Their human hunters, the Clovis people,...

Early Americans faced rapid late Pleistocene climate change and chaotic environments The environment encountered when the first people emigrated into the New World was variable and ever-changing, according to a Penn State geologist. "The New World was not a nice quiet place when humans came," says Dr. Russell Graham, associate professor of geology and director of the Earth & Mineral Sciences Museum. Archaeologists agree that by 11,000 years ago, people were spread across North and South America, but evidence is building for an earlier entry into the New World, a date that would put human population of North and South...

Contact: Joel Schwarz joels@u.washington.edu 206-543-2580 University of Washington Evidence acquits Clovis people of ancient killings, archaeologists say Archaeologists have uncovered another piece of evidence that seems to exonerate some of the earliest humans in North America of charges of exterminating 35 genera of Pleistocene epoch mammals. The Clovis people, who roamed large portions of North America 10,800 to 11,500 years ago and left behind highly distinctive and deadly fluted spear points, have been implicated in the exterminations by some scientists. Now researchers from the University of Washington and Southern Methodist University who examined evidence from all suggested Clovis-age killing sites...

Hour-long hailstorm may have caused 1,000-year freeze, say scientists An hour-long hailstorm from space may have changed the climate of the Earth in 11,000 BC, leading to a freeze lasting more than 1,000 years, scientists say. Published: 8:00AM BST 02 Apr 2010 An hour-long hailstorm from space may have changed the climate of the Earth in 11,000 BC, leading to a freeze lasting more than 1,000 years, scientists say. A comet may well have caused the earth to freeze for over 1,000 years Photo: GETTY The catastrophe, caused by a disintegrating comet, wiped out large numbers of animal species and...

A controversial theory that suggests an extraterrestrial body crashing to Earth almost 13,000 years ago caused the extinction of many large animals and a probable population decline in early humans is gaining traction from research sites around the world. The Younger Dryas Impact Hypothesis, controversial from the time it was presented in 2007, proposes that an asteroid or comet hit the Earth about 12,800 years ago causing a period of extreme cooling that contributed to extinctions of more than 35 species of megafauna including giant sloths, sabre-tooth cats, mastodons and mammoths. It also coincides with a serious decline in early...

Along with locations in North and South America, Greenland, Western Europe, and the Middle East, we can now add southern Africa to the list of places where scientists have uncovered evidence of a calamitous event that happened 12,800 years ago. This evidence of a 12,800-year-old platinum spike in Africa is the first to be found on the continent, and it’s yet further evidence in support of the Younger Dryas Impact Hypothesis. According to this theory, either a comet or asteroid struck Earth during the Pleistocene, triggering an impact winter that saw temperatures plummet around the globe. The associated loss of...

Following the discovery of the 19.2-mile wide Hiawatha impact crater beneath the northwest margin of the Greenland Ice Sheet, Dr. Joe MacGregor of NASA’s Goddard Space Flight Center and colleagues explored satellite and aerogeophysical data in search of additional such craters and found a possible second impact crater that is 22.7 miles wide and 114 miles southeast of the Hiawatha crater. The discovery is described in a paper in the journal Geophysical Research Letters. ..." Following the finding of that first crater, Dr. MacGregor and co-authors checked topographic maps of the rock beneath Greenland’s ice for signs of other craters....

An international team of geoscientists from the United States, Canada and Europe has discovered a large impact crater beneath the Hiawatha Glacier in remote northwest Greenland. A paper on the discovery was published in the journal Science Advances. The Hiawatha impact crater is approximately 19.2 miles (31 km) wide and lies under an ice sheet that is 0.6 miles (1 km) thick.The scientists believe this crater was formed by a 0.6-mile wide iron asteroid that slammed into the Earth at the end of the Pleistocene epoch, perhaps as recently as 12,000 years ago. ..." “Researchers were looking at the map...

On a bright July day 2 years ago, Kurt Kjær was in a helicopter flying over northwest Greenland—an expanse of ice, sheer white and sparkling. Soon, his target came into view: Hiawatha Glacier, a slow-moving sheet of ice more than a kilometer thick. It advances on the Arctic Ocean not in a straight wall, but in a conspicuous semicircle, as though spilling out of a basin. Kjær, a geologist at the Natural History Museum of Denmark in Copenhagen, suspected the glacier was hiding an explosive secret. The helicopter landed near the surging river that drains the glacier, sweeping out rocks...

New data from Greenland ice cores suggest North America may have suffered a large cosmic impact about 12,900 years ago. A layer of platinum is seen in ice of the same age as a known abrupt climate transition, US scientists report. The climate flip has previously been linked to the demise of the North American "Clovis" people. The data seem to back the idea that an impact tipped the climate into a colder phase, a point of current debate. Rapid climate change occurred 12,900 years ago, and it is proposed that this is associated with the extinction of large mammals...

Greenland ice core analysis shows drastic climate change near end of last ice age Caption: The North Greenland Ice Core Project camp. Credit: NGRIP Temperatures spiked 22 degrees F in just 50 years, researchers say Information gleaned from a Greenland ice core by an international science team shows that two huge Northern Hemisphere temperature spikes prior to the close of the last ice age some 11,500 years ago were tied to fundamental shifts in atmospheric circulation. The ice core showed the Northern Hemisphere briefly emerged from the last ice age some 14,700 years ago with a 22-degree-Fahrenheit spike in just...

A carbon-rich black layer, dating to 12.9 ka, has been previously identified at 50 Clovis-age sites across North America and appears contemporaneous with the abrupt onset of Younger Dryas (YD) cooling. The in situ bones of extinct Pleistocene megafauna, along with Clovis tool assemblages, occur below this black layer but not within or above it. Causes for the extinctions, YD cooling, and termination of Clovis culture have long been controversial. In this paper, we provide evidence for an extraterrestrial (ET) impact event at 12.9 ka, which we hypothesize caused abrupt environmental changes that contributed to YD cooling, major ecological reorganization,...

Wooly mammoths, giant sloths, saber-toothed cats, and dozens of other species of megafauna may have become extinct when a disintegrating comet or asteroid exploded over North America with the force of millions of hydrogen bombs, according to research by an international team of scientists. The blast, which the researchers believe occurred 12,900 years ago, may have also doomed a mysterious early human culture, known as Clovis people, while triggering a planetwide cool-down that wiped out the plant species that sustained many outsize Ice Age beasts, according to research published online yesterday in the Proceedings of the National Academy of Sciences.

Contact: Lisa Nelson Lisa.Nelson@nau.edu 928-523-6123 Northern Arizona University Research team says extraterrestrial impact to blame for Ice Age extinctions A colorized scanning electron microscope image of a glassy carbon sphere that contains evidence of extraterrestrial impact. The sphere measures about .012 inches in width. What caused the extinction of mammoths and the decline of Stone Age people about 13,000 years ago remains hotly debated. Overhunting by Paleoindians, climate change and disease lead the list of probable causes. But an idea once considered a little out there is now hitting closer to home. A team of international researchers, including two Northern...

A "black mat" of algal growth in Arizona marks the extinction of mammoths 12,900 years ago New scientific findings suggest that a large comet may have exploded over North America 12,900 years ago, explaining riddles that scientists have wrestled with for decades, including an abrupt cooling of much of the planet and the extinction of large mammals. The discovery was made by scientists from the University of California at Santa Barbara and their colleagues. James Kennett, a paleoceanographer at the university, said that the discovery may explain some of the highly debated geologic controversies of recent decades. The period in...

June 28, 2007 Comet theory collides with Clovis research, may explain disappearance of ancient people A theory put forth by a group of 25 geo-scientists suggests that a massive comet exploded over Canada, possibly wiping out both beast and man around 12,900 years ago, and pushing the earth into another ice age. University of South Carolina archaeologist Dr. Albert Goodyear said the theory may not be such "out-of-this-world" thinking based on his study of ancient stone-tool artifacts he and his team have excavated from the Topper dig site in Allendale, as well as ones found in Georgia, North Carolina and...

Don't look now, but another big chunk of the "evidence" for man-made global warming suddenly disappeared. Poof! Researchers just reported that the world's most recent case of "abrupt climate change"—which occurred a mere 12,000 years ago—was probably due to a comet strike, not to "climate sensitivity." The Younger Dryas occurred as an Ice Age was ending. As the climate began to warm, a huge and sudden rush of fresh meltwater broke out from the Great Lakes and swept out to sea. The water surge was monumental enough that the meltwater lowered the salinity of the ocean, shut down the Atlantic...

mammoth some 12,900 years ago. A team of two dozen scientists say the culprit was likely a comet that exploded in the atmosphere above North America. The explosions sent a heat and shock wave across the continent, pelted the ground with a layer of telltale debris, ignited massive wildfires and triggered a major cooling of the climate, said nuclear analytic chemist Richard Firestone of Lawrence Berkeley Laboratory, one of the scientists who presented the controversial new theory Thursday at a conference of the American Geophysical Union in Acapulco. At least 15 species, mostly large mammals including mammoths, mastadons, giant ground...

Contact: Jim Barlow jebarlow@uoregon.edu 541-346-3481 University of Oregon Oregon researchers involved in new Clovis-age impact theory Did a comet hit the Great Lakes region and fragment human populations 12,900 years ago? 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...

Catastrophic Comet Chilled and Killed Ice Age Beasts Jeanna Bryner LiveScience Staff Writer LiveScience.com Mon May 21, 9:30 AM ET An extraterrestrial object with a three-mile girth might have exploded over southern Canada nearly 13,000 years ago, wiping out an ancient Stone Age culture as well as megafauna like mastodons and mammoths. The blast could be to blame for a major cold spell called the Younger Dryas that occurred at the end of the Pleistocene Epoch, a period of time spanning from about 1.8 million years ago to 11,500 years ago. Research, presented today at a meeting of the American...