In terms of prehistoric caves, Chauvet is that held until now the dean of French title: its walls were adorned with paintings there are 37 000 years, according to the latest estimates. We also have the Cussac cave in the Dordogne, where a tomb has been dated to – 28 500 years, and of course Lascaux granny with respectable 22,000 years old. Pfff! Just little girls … The history of underground exploration by prehistoric man just out of whack with the publication on Wednesday in Nature , a study from the man’s passage into cave Bruniquel 176 500 years. Making it, by far, the world record in the discipline.
This is where the nested surprise. 30 meters approximately square, pieces of torn stalagmites are arranged in a circle. Most lying horizontally stacked, others supporting this dam case was like. And a bear bones burned. The trace of the man … These findings are listed and described for the first time in a review of caving, Spelunca , with age attributed to the piece of bone: at least 47,000 years – not go further with this old carbon 14. A widely as previous age paintings of Chauvet should already have put a flea in the ear of historians, but the news is hardly reached them. And the cave was closed on his private property to the secret location for fifteen years.
Dating Techniques
It is only in 2011 that received a new Bruniquel Away in the person of Sophie Verheyden, a researcher at the Royal Institute of Natural sciences in Belgium. She in turn is quite baffled by the strange stalagmite structures and request permission to restart the studies. Is that dating techniques have come a long way since the discovery of the cave: the method radioactive “uranium-thorium” now lets go back to – 600 000 years, and is not limited to organic matter such as carbon 14; it also works with sedimentary minerals like stalagmites. That’s good. So here’s the plan of attack for the team “Bruniquel: the return” consisted of Sophie Verheyden, Jacques Jaubert and research director at CNRS Dominique Genty: make a survey of the cave in 3D, measure the magnetism of the cavity to locate the burned material cored and stalagmites.
The idea is simple and brilliant Verheyden. The end of the stalagmite was formed just before the prehistoric man for the hard to arrange the food so it informs about the time immediately preceding the construction of the structure. And after the man’s visit, the water continued to drip on the structure, forming a little everywhere “regrowth” of vertical stalagmites. If one day the basis of these volunteers, we find the time immediately following construction. Six carrots two centimeters in diameter were performed to compare the results to average and reduce errors. After a short stay in the US and Chinese laboratories, the results fall. Bingo! The end date of the drives lying stalagmites and date pushes match perfectly. Sophie Verheyden Jacques Jaubert called to give him the number. He saw the moment as if it were yesterday: “I was on holiday in Italy, it was in August. I can tell you on what course of stairs I was exactly when my phone rang. She gave me a completely unprecedented time 176 500 years. And there were several very consistent and reliable results. Frankly, we had not expected at all to such an old age, as breathtaking. “
” Stalagmites in a circle “
Because we knew that man modern – also called homo sapiens, or Cro-Magnon – visited the caves to adorn the paintings or deposit any graves. But – 176,500 (with a margin of error of two thousand years ago), Homo sapiens has not landed in Europe. The culprit is the Neanderthals, that old cousin whom nothing is known lifestyle “when leaving the register of subsistence, food and technology” , according Jacques Jaubert. This “quasi documentary total nothingness” is just beginning to be filled by the discoveries of Bruniquel. “The appropriation of the underworld by the Neanderthals, it’s really something completely new. If someone had told me that there a few years ago I would have been very skeptical. “
The presence of this learned assembly of stalagmites 335 meters from the entrance of the cave, in complete darkness, guess Neanderthal handled torches underground long before modern man. “It was probably a group, a group with people who lit while others carried agençaient and stalagmites” , assuming Jaubert. So there were different roles, divided between individuals. Coordination and exchanges. Perhaps also a hierarchy, a leader who gave the orders. Not to mention the pre-research phase and choice of materials to mount the odd structure. The work was complex: there are 400 “speleofacts” in the cavity – a neologism created by our three researchers to denote speleothems (mineral concretions) transformed by man
The prehistoric cave visitors. “ripped stalagmites, have them switched, sectioned, fragmented, sectioned and even calibrated to arrange circularly or pile them in the central parts of the structure, according to a plan that was definitely predetermined. Men have moved between 2.1 tons and 2.4 tons of materials. This is not a trivial matter. “ The builders certainly had a ” Upstream objective “, but it is impossible to know at this time. “By elimination, we can assume that there are not too many reasons habitat type, technical or nutritional reasons … We are progressively cornered in the field of the intangible, that it is hard to to understand these very old times. “ From art? A rite or a cult? “This is very dangerous ground, and you really have to think twice before letting such a word.”
The speculations are premature. The question of why come later. For now, “we are rather in a preliminary phase description” , which has also given some trouble to the French researchers when reviewers for publication in Nature asked them to prove that the structure was man-made, that is to say, human. The ring stalagmites looks well organized, but we can be totally exclude the possibility of a landslide or a stuffed bear that would have shot in the stalagmites in the cave?
Dominique Genty details the different evidence we have at hand: first, the magnetic anomaly map produced in the cave shows the different places where magnetite was formed by heating the minerals. This map coincides with the surveys homes by researchers observing reddened calcite or blackened by fire. Then there’s this piece of bone that has been stuck between a stalagmite and lying regrowth. “This is bone char , says Genty. It was analyzed with an infrared spectrum, and we know that it was heated to 300 or 400 degrees. “ So the man has been there, with its prehistoric matches, when stalagmites were installed. Finally, this is not a formal proof but stalagmite sections have obviously all a similar size: there is an average size for the sections of the large circular structure, and another average size for smaller structures. Gold “Nature does not calibrate the stalagmite” .
Glow flashlights
Are Neanderthals came up their structure in one go? Have they visited the cave for several seasons? And first, how long does it take to skillfully organize two tons of stalagmites in torchlight, 50 meters deep? “how to answer that We promised to give” , the three researchers are enthusiastic, who rely study well Bruniquel many years to come. In the 2016 program, they provide some experimental archeology: “We must find a cave that is accessible, with enough concretions that we can move … We would like to manipulate speleothems.” and also date the closing of the cave, although less accessible today than middle Paleolithic, and then review those fingerprints and these bear scratches deep in the cave, in an area that has not yet dared explore fear of damage. Perhaps there he has other human traces from that side? The history of Bruniquel is still in its early chapters
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