Mammoths and Other Great Beasts Peppered with Material from Space
2007 12 12
By Jonathan Amos | news.bbc.co.uk
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.
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.
But having gone out and tested the hypothesis of tusk impacts, and having apparently uncovered such items - the team was then astonished to find the animal remains were about 20,000 years older than had been anticipated.
The researchers are now considering a number of possibilities - one that could even tie the older remains to the younger event.
"People who collect these items today in Siberia and Alaska frequently find the tusks sticking out of the permafrost or eroding out of a riverbank," explained Mr West.
The embedded particles have a high iron-nickel content
"Maybe, these were tusks from dead animals that were just exposed on the surface, so when this thing blew up in the atmosphere, it would have peppered them. The date could really be anywhere from 13,000 to 35-40,000 years ago."
The team believes there must still be peppered tusks out there that can be dated to 13,000 years ago, and the hope is that the AGU presentation will prompt museums and collectors to look through their archives.
"There should also be a layer of this same meteoritic material in the sedimentary record. It's probably very thin. If we can locate the right place and it hasn't been turbated, we should be able to find this layer; and it shouldn't be too different from the impact layer we found for the 13,000-year event," said Dr Firestone.
Neither proposed impact can yet be tied definitively to any craters - if there ever were any. The team also needs to explain how the bison and mammoth remains can show similar damage when they were widely separated geographically.
The intriguing question is how space impacts might fit into the extinction story of the ice age beasts. The mammoth, their elephant cousins the mastodon, sabre-toothed tigers, some bears, and many other creatures all disappeared rapidly from the palaeo-record about 10,000 years ago.
Their loss has traditionally been put down to either climate change and/or the efficient hunting technologies adopted by migrating humans.
Could impacts have also weakened these populations?
It might be just one more element to factor into what is a really complex picture, commented Dr Ian Barnes from Royal Holloway University of London, UK.
The British researcher studies the DNA of ancient animals to try to glean details of how their populations changed over time.
He said there were some interesting markers in the genetics of different creatures some 30,000 to 45,000 years ago - but it was extremely hard to draw firm conclusions.
"For us the difficulty is that we see patterns but we don't understand what the underlying process is; so it becomes difficult to ascribe causation," he explained.
"Just as in a modern crime scene, it's very difficult to piece all the evidence together and say precisely what was going on; which event led to any particular outcome."
But he added: "Certainly, you can't imagine it helped the animals having a large meteorite hit the Earth's atmosphere and pellet them with shot."
* Large beast populations crashed 10,000 years agoArticle from: http://news.bbc.co.uk/2/hi/science/nature/7130014.stm
* Includes mammoth, mastodon, sabre-toothed tigers, giant sloth
* Scientists have several theories to explain the extinctions
* Human hunters had adopted a deadly spear-point technology
* Climate changes may have hastened animals' demise
* Do space impacts also now need to be considered?
Diamonds tell tale of comet that killed off the cavemen
Climate change from a meteor impact, what do we know so far?
Giant impact added to Earth's core
Massive Impact in the Kuiper Belt 4.5 Billion Years Ago
Ice Age blast 'ravaged America'
Tut's gem hints at space impact
Sandia Supercomputer Helps Researchers Discover Origin of Mysterious Glass Found in King Tut's Tomb
Libya's Kebira Crater
The Dragon and the Pearl
Ossified Dragon Theories
The Origins of Doomsday Anxiety
'Lunar Ark' Proposed in Case of Deadly Impact on Earth
Red Ice Creations Radio - Michael Tsarion - Lucifer & The Dark Side of the Sun
Red Ice Creations Radio - Joseph P. Farrell - The Giza Death Star (Subscription)
Red Ice Creations Radio - Joseph P Farrell - Cosmic War, Interplanetary Warfare & Mesopotamian Mythology
Red Ice Creations Radio - Joseph P Farrell - Interplanetary Warfare, Mythology & Nazi Occultism (Subscription)
Red Ice Creations Radio - Andy Lloyd - Dark Star, Evidence for Planet X
Red Ice Creations Radio - Michael Tsarion - Irish Origins Part 1 - The West to East Movement of Civilization, Land Bridges & Age of Catastrophe
The Exploded Planet Hypothesis 2000 - Tom Van Flandern, Meta Research
Ancient Plant Remains Discovered Two Miles Below Greenland Ice Sheet; Evidence Questions Current Ice Age Theories
North Pole 'was once subtropical'
Fossil DNA Proves Greenland Once Had Lush Forests; Ice Sheet Is Surprisingly Stable
Latest News from our Front Page
US Silent on Psychologists Role in CIA’s Tortures: Doctors
Physicians for Human Rights had not received any response from the US Federal Commission to their call to investigate the role of health professionals in CIA’s torture program, Deputy Director of the organization told Sputnik.
December 19 (Sputnik) — US government has not responded to calls to prosecute doctors, who participated in CIA torture program, the Deputy Director of Communications for ...
Ziolebrities: Simon Cowell donates £100,000 to Israeli soldiers to please pregnant jewish girlfriend Lauren Silverman
Cowell, 54, is also planning a secret trip to Israel soon as he embraces the Jewish faith of Silverman, 36
Gala: Billionaire Haim Saban with Cowell
Simon Cowell has publicly donated nearly £100,000 in support of the Israeli army.
The X Factor boss pledged the cash to the Friends of the Israel Defense Forces at a US fund-raiser in Beverly Hills.
The lavish gala ...
Former Chief Security Officer for NewsCorp: N. Koreans Not Behind Sony Hack, Interview Leak
Hemanshu Nigam, a former federal prosecutor and former chief security officer for NewsCorp/Fox studios, says North Korea isn’t behind the Sony Hack.
Nigam gave several bullet points for why the hack was likely an inside job.
Attack code borrowed from a previous attack on Seoul, that’s why it’s in Korean. Private hackers typically borrow malicious code from other hackers.Nations state attacks follow ...
Sony Fires Back at Obama: Actually We Did Call the White House – Several Times
Sony fired back at Obama after the press conference saying they had several conversations with the Obama White House before and after the movie was canceled.
Via The Hollywood Reporter:
After President Obama criticized Sony for its decision to cancel The Interview's release after theater chains decided not to show the film, the studio has issued a statement elaborating on the move.
The Bankster International
Geopolitical analysis, the art of explaining power relationships through the prism of impersonal geography, can be a helpful tool for observers of the Great Game – but it also has its limitations. A case in point is the renewed US-Russia confrontation. Think tanks and policy insiders easily sell the narrative that from the dark days of the Cold War to ...
|More News » |