The age of stone tools found in a Brazilian rock shelter is estimated at 22 thousand years. This again suggests that the ancient people reached America long before the famous hunters of the North American culture of Clovis, which existed about 13 thousand years ago.
Geochronologist Christelle Laye from the University of Bordeaux-3 and archaeologist Eric Boeda from the University of Paris-10 (both from France) argue that the question of the alleged primacy of the Clovis culture bearers is closed, but not everyone agrees.
The most controversial rock shelter of all that claim to refute the hypothesis of the primacy of the Clovis culture is Pedra Furada. A burnt tree and pointed stones were found there in layers more than 50 thousand years old, but skeptics believe that this is the result of forest fires and landslides.
This time, the artifacts were found at the site of Toca da Tira Peyia, located in the same national park. It would seem that you cannot argue with a projectile that fell into the same funnel twice, but no, critics point out that there is a steep rock in this place, and stones with sharp edges may be the result of falling from a great height, and not the work of a person. This is the opinion, for example, of archaeologist Gary Haynes of the University of Nevada (USA). His colleague Stuart Fidel from the environmental consulting firm Louis Berger Group (USA) does not exclude that these "tools" were created or used by Capuchins or other apes.
The dating of the finds is also questionable. Usually age is determined by the amount of time that objects have lain in the ground. But fluctuations in soil moisture and other factors can skew the estimate, Mr. Haynes recalls.
However, archaeologist Tom Dilhey from Vanderbilt University (USA) saw some finds from Toca da Tira Peyia and considered them anthropogenic. According to him, similar tools have been excavated at sites in Chile and Peru. Earlier, his group calculated that people first settled in Monte Verde (Chile) at least 14 thousand years ago, or even all 33 thousand.
The lack of charred wood and other radiocarbon dating sites in Toca da Tira Peyia is, of course, a problem because it is the standard method for estimating the age of sites under 40,000 years old, Mr. Dilhei notes. But if a person really reached South America 20 thousand years ago, one would expect just such traces - a scanty material scattered in several refuges within the same geographical area.
Laye and Boeda excavated Toca da Tira Peyia from 2008 to 2011. They managed to find 113 stone artifacts, which they interpreted as tools and production waste. They occupy five soil layers. Using a method that measures the natural radiation damage of quartz grains, scientists have suggested that the top layer last saw the sun 4,000 years ago, and the third from above, 22,000 years ago.
Promotional video:
The 15 artifacts from the bottom two layers should be even older, but they have not yet been dated.
The study is published in the Journal of Archaeological Science.
Antonenko Andrey