Hélène Valladas

Paleoindian Cave Dwellers in the Amazon: The Peopling of the Americas

A Paleoindian campsite has been uncovered in stratified prehistoric deposits in Caverna da Pedra Pintada at Monte Alegre in the Brazilian Amazon. Fifty-six radiocarbon dates on carbonized plant remains and 13 luminescence dates on lithics and sediment indicate a late Pleistocene age contemporary with North American Paleoindians. Paintings, triangular bifacial spear points, and other tools in the cave document a culture distinct from North American cultures. Carbonized tree fruits and wood and faunal remains reveal a broad-spectrum economy of humid tropical forest and riverine foraging. The existence of this and related cultures east of the Andes changes understanding of the migrations and ecological adaptations of early foragers.

ESR dates for the hominid burial site of Qafzeh in Israel

Abstract Early modern hominids are found buried at the mouth of a cave at Qafzeh near Nazareth, Israel. They are associated with a Middle Paleolithic lithic industry. Previous dating of this site by TL analysis of burnt flint (Valladas et al., 1988) gave an age of 92 ± 5 kyr. We have now used the ESR method to date enamel of teeth of large mammals from the hominid-bearing layers. Assuming a constant rate of uptake of U through time by the teeth, we obtain an age of 115 ± 15 kyr. This is consistent with the TL results demonstrating early arrival of fully modern humans in Southwestern Asia.

Thermoluminescence dating of flint

Abstract Our ancestors have been making flint tools for over a million years. The tools or the flakes left by the flint-knappers have become important markers of prehistoric habitats. The imperishable and ubiquitous nature of flint explains why generations of prehistorians have used it to build a stone age chronology. To be dateable by TL flint must be heated to at least 450°C. While human use of fire may be as old as half a million years, the first true hearths appear late during the Lower Paleolithic period. At Terra-Amata, one of the oldest hearths discovered in France was dated to 230 ± 40 ka BP by Wintle and Aitken (1977). By the dawn of the Middle Paleolithic fire must have become fully domesticated, judging by the accumulations of charred debris that henceforth litter human habitats. For example, at the Middle Paleolithic site of Kebara the profusion of hearths is vividly illustrated by numerous superposed white ash and black charcoal layers extending to a depth of 4 m (Meignen et al. , 1989).

ESR dating of the Neanderthal site, Kebara Cave, Israel

Abstract In 1985 a Neanderthal skeleton was found in the cave of Kebara in southern Mt. Carmel. Electron spin resonance (ESR) dates have been obtained on tooth enamel of gazelles found in layer X, just overlying the layer in which the skeleton was found. Assuming early uptake of uranium by the teeth, they yield an age of 60 ± 6 ka; assuming gradual, linear uptake of uranium yields an age of 64 ± 6 ka. Both age estimates are consistent with a previous estimate for the skeleton, based on TL dating of burnt flint, of 60 ± 4 ka.

Flint thermoluminescence dates from the CFR laboratory at Gif: Contributions to the study of the chronology of the middle palaeolithic

Abstract Flint tools are among the most durable objects marking the presence of prehistoric humans. Methodological advances of the last decade have made thermoluminescence of burnt flint a reliable dating tool and have provided new dates which require reassessment of the chronology of numerous Middle Palaeolithic sites. Dates for several Near Eastern sites show the presence of Neanderthals from at least oxygen isotope stage 6 until after 50 ka ago and push the appearance of modern humans to before 100 ka ago, long before their arrival in Europe. Whether the two populations were present continuously or intermittently and precisely when they appeared is uncertain at the moment. Thermoluminescence results suggest that the Mousterian lithic industries were introduced at about the same time in Europe as in the Near East, with the difference that in the latter area this industry was used by early modern humans as well as by Neanderthals. The new TL chronology assigns a much longer life-span to specific types of Levantine Mousterian lithic industries than previously believed. Finally, new dates for the Châtelperronian site of Saint-Cesaire open up the possibility that the last Neanderthals were still present after some Cro-Magnons had already settled in western Europe.

Middle Palaeolithic bitumen use at Umm el Tlel around 70,000 BP

The authors identify natural bitumen on stone implements dating to 70,000 BP. It is proposed that this represents residue from hafting, taking the practice back a further 30,000 years from the date previously noted and published in Nature. The bitumen was tracked to a source 40km away, using gas chromatography-mass spectrometry and carbon isotopes

Context and dating of Aurignacian vulvar representations from Abri Castanet, France

We report here on the 2007 discovery, in perfect archaeological context, of part of the engraved and ocre-stained undersurface of the collapsed rockshelter ceiling from Abri Castanet, Dordogne, France. The decorated surface of the 1.5-t roof-collapse block was in direct contact with the exposed archaeological surface onto which it fell. Because there was no sedimentation between the engraved surface and the archaeological layer upon which it collapsed, it is clear that the Early Aurignacian occupants of the shelter were the authors of the ceiling imagery. This discovery contributes an important dimension to our understanding of the earliest graphic representation in southwestern France, almost all of which was discovered before modern methods of archaeological excavation and analysis. Comparison of the dates for the Castanet ceiling and those directly obtained from the Chauvet paintings reveal that the “vulvar” representations from southwestern France are as old or older than the very different wall images from Chauvet.

Cross dating (Th/U-14C) of calcite covering prehistoric paintings in Borneo

Abstract We present the first application of cross-dating (Th/U measured by thermo-ionization mass spectrometry (TIMS) and 14C measured by accelerator mass spectrometry (AMS)) of calcite covering prehistoric paintings. Th/U age estimates of cave drapery range from 9800 to 27,300 yr B.P. while conventional 14C age is estimated between 9900 and 7610 yr B.P. depending on the dead carbon correction. The age discrepancy is attributed to a disturbance of Th/U and/or 14C geochemical systems, showing the limits of the geochronological approach applied to this kind of material. For the Th/U system, the poor consistency of U data (U content, 234U/238U activity ratios) and apparent ages argue for open system conditions. For 14C system, variation of the dead carbon fraction (dcf) and a possible mixing of successive generations of calcite could account for age discrepancy. Nevertheless, one sample shows concordant ages for the two methods. Compatible ages through corrections for open system conditions are assumed for other samples. Then, the cross-dating suggests 9900 yr as the minimum age of the piece of drapery; the underlying painting must be older. This study of rock art demonstrates the presence of a Pleistocene population before 9900 yr in the southeast of Borneo, whereas previously the only population in evidence in this area was of Austronesian type from ∼5000 to 6000 yrs ago.

Dating the Lower to Middle Paleolithic transition in the Levant: A view from Misliya Cave, Mount Carmel, Israel

The transition from the Lower to the Middle Paleolithic in the Levant is a crucial event in human evolution, since it may involve the arrival of a new human population. In the current study, we present thermoluminescence (TL) dates obtained from 32 burnt flints retrieved from the late Lower Paleolithic (Acheulo-Yabrudian) and Early Middle Paleolithic (Mousterian) layers of Misliya Cave, Mount Carmel, Israel. Early Middle Paleolithic industries rich in Levallois and laminar products were assigned mean ages ranging from ~250 to ~160 ka (thousands of years ago), suggesting a production of this industry during MIS 7 and the early part of MIS 6. The mean ages obtained for the samples associated with the Acheulo-Yabrudian (strengthened by an isochron analysis) indicate a production of this cultural complex ~250 ka ago, at the end of MIS 8. According to the Misliya TL dates, the transition from the Lower to the Middle Paleolithic in the site took place at the limit MIS 8/7 or during the early part of MIS 7. The dates, together with the pronounced differences in lithic technology strongly suggest the arrival of a new population during this period.

Radiocarbon intercomparison program for Chauvet Cave

We present the first results of an accelerator mass spectrometry (AMS) radiocarbon intercomparison program on 3 different charcoal samples collected in one of the hearths of the Megaceros gallery of Chauvet Cave (Ardche, France). This cave, rich in parietal decoration, is important for the study of the appearance and evolution of prehistoric art because certain drawings have been 14C dated to the Aurignacian period at the beginning of the Upper Paleolithic. The new dates indicate an age of about 32,000 BP, which is consistent with this attribution and in agreement with the results from the same sector of the cave measured previously at the Laboratoire des Sciences du Climat et de lEnvironnement (LSCE). Six laboratories were involved in the intercomparison. Samples were measured in 4 AMS facilities: Center for Isotope Research, Groningen University, the Netherlands; the Oxford Radiocarbon Accelerator Unit, UK; the Centre de datation par le carbone 14, Univ. Claude Bernard Lyon 1, France (measured by AMS facilities of Poznan University, Poland); and the LSCE, UMR CEACNRS-UVSQ, France (measured by the Leibniz-Labor of Christian-Albrechts-Universitt Kiel, Germany).