Startling evidence has been found which shows mammoth and other great beasts from the last ice age were blasted with material that came from space.
Eight tusks dating to some 35,000 years ago all show signs of having being peppered with meteorite fragments. The ancient remains come from Alaska, but researchers also have a Siberian bison skull with the same pockmarks. The scientists released details of the discovery at a meeting of the American Geophysical Union in San Francisco, US.
They painted a picture of a calamitous event over North America that may have severely knocked back the populations of some species. "We think that there was probably an impact which exploded in the air that sent these particles flying into the animals," said Richard Firestone from the Lawrence Berkeley National Laboratory. "In the case of the bison, we know that it survived the impact because there's new bone growth around these marks." And geoscience consultant Allen West added: "If the particles had gone through the skin, they may not have made it through to vital organs; but this material could certainly have blinded the animals and severely injured them." The mammoth and bison remains all display small (about 2-3mm in size) perforations. Raised, burnt surface rings trace the point of entry of high-velocity projectiles; and the punctures are on only one side, consistent with a blast coming from a single direction. Viewed under an electron microscope, the embedded fragments appear to have exploded inside the tusk and bone, say the researchers. Shards have cut little channels. The sunken pieces are also magnetic, and tests show them to have a high iron-nickel content, but to be depleted in titanium. The ratios of different types of atoms in the fragments meant it was most unlikely they had originated on Earth, the team told the AGU meeting.
Magnetic hunt
The discovery follows on from the group's previous research which claimed a more recent space collision - some 13,000 years ago. The researchers reported the discovery of sediment at more than 20 sites across North America that contained exotic materials: tiny spheres of glass and carbon, ultra-small specks of diamond and amounts of the rare element iridium that were too high to be terrestrial. The scientists also found a black layer which, they argued, was the charcoal deposited by wildfires that swept the continent after the space object smashed into the Earth's atmosphere. "We had found evidence of particle impacts in chert, or flint, at a Clovis Indian site in Michigan," Dr Firestone said. "So, we got the idea that if these impacts were in the chert, then they might likely also have occurred in large surfaces such as tusks; and we decided it was worth a shot to go look for them." Allen West began the hunt at a mammoth tusk sale in his home state of Arizona. He immediately found one tusk with the tell-tale pockmarks and asked the trading company if he could look through its entire collection.
He sorted literally thousands of items. "There are many things that can cause spots, such as algae, and there were a few of those; but I was only interested in the ones that were magnetic," he recalled. "It was just a tiny magnet on a string, but very strong. It would swing over and stick firmly to these little dots." The search turned up a further seven ivory specimens of interest, together with the bison skull.
by www.thesupernaturalworld.co.uk
Eight tusks dating to some 35,000 years ago all show signs of having being peppered with meteorite fragments. The ancient remains come from Alaska, but researchers also have a Siberian bison skull with the same pockmarks. The scientists released details of the discovery at a meeting of the American Geophysical Union in San Francisco, US.
They painted a picture of a calamitous event over North America that may have severely knocked back the populations of some species. "We think that there was probably an impact which exploded in the air that sent these particles flying into the animals," said Richard Firestone from the Lawrence Berkeley National Laboratory. "In the case of the bison, we know that it survived the impact because there's new bone growth around these marks." And geoscience consultant Allen West added: "If the particles had gone through the skin, they may not have made it through to vital organs; but this material could certainly have blinded the animals and severely injured them." The mammoth and bison remains all display small (about 2-3mm in size) perforations. Raised, burnt surface rings trace the point of entry of high-velocity projectiles; and the punctures are on only one side, consistent with a blast coming from a single direction. Viewed under an electron microscope, the embedded fragments appear to have exploded inside the tusk and bone, say the researchers. Shards have cut little channels. The sunken pieces are also magnetic, and tests show them to have a high iron-nickel content, but to be depleted in titanium. The ratios of different types of atoms in the fragments meant it was most unlikely they had originated on Earth, the team told the AGU meeting.
Magnetic hunt
The discovery follows on from the group's previous research which claimed a more recent space collision - some 13,000 years ago. The researchers reported the discovery of sediment at more than 20 sites across North America that contained exotic materials: tiny spheres of glass and carbon, ultra-small specks of diamond and amounts of the rare element iridium that were too high to be terrestrial. The scientists also found a black layer which, they argued, was the charcoal deposited by wildfires that swept the continent after the space object smashed into the Earth's atmosphere. "We had found evidence of particle impacts in chert, or flint, at a Clovis Indian site in Michigan," Dr Firestone said. "So, we got the idea that if these impacts were in the chert, then they might likely also have occurred in large surfaces such as tusks; and we decided it was worth a shot to go look for them." Allen West began the hunt at a mammoth tusk sale in his home state of Arizona. He immediately found one tusk with the tell-tale pockmarks and asked the trading company if he could look through its entire collection.
He sorted literally thousands of items. "There are many things that can cause spots, such as algae, and there were a few of those; but I was only interested in the ones that were magnetic," he recalled. "It was just a tiny magnet on a string, but very strong. It would swing over and stick firmly to these little dots." The search turned up a further seven ivory specimens of interest, together with the bison skull.
by www.thesupernaturalworld.co.uk
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