It has been argued that the mix of Neanderthals, Middle Paleolithic tools, and Upper Paleolithic technology was the result of cryoturbation and lithic assemblage has parallels with the Szeletian technocomplex, and further, that there is a mixture of elements of Szeletian and Aurignacian I and II within the level [see also Svoboda (18)].
Karavanić and Smith (19) have suggested that the mixture of elements may represent the interaction and possible acculturation between modern humans and late Neanderthals.
It has become clear that there have been major problems with dating reliability and accuracy across the Paleolithic in general, with studies highlighting issues with underestimation of the ages of different dated samples from previously analyzed sites (6). At Mezmaiskaya, the AMS dates obtained for the Neanderthal excavated above the previously dated individual were substantially older (9). In both cases, revised radiocarbon dates produced with more robust chemical pretreatment methods have illustrated significant underestimates in the previous dates that cannot be reconciled with a hypothesis of late-surviving refugial Neanderthals. However, for Vi-207, the 30-k Da fraction obtained produced a C/N ratio of 4.3, which indicates the presence of a high molecular weight contaminant.
These dates suggest a co-occurrence of early Upper Paleolithic osseous artifacts, particularly split-based points, alongside the remains of Neanderthals is a result of postdepositional mixing, rather than an association between the two groups, although more work is required to show this definitively. Significant questions still remain regarding the precise nature of this transition, the humans responsible for the various transitional early Upper Paleolithic industries, the degree of overlap between Neanderthals and modern humans, and the timing of the disappearance of the former.
K-Ar and dating of supergene K-bearing manganese oxides formed during lateritization of Archean and Proterozoic bedrocks in the Carajâs Region, Amazonia, Brazil, indicates that weathering started before 72 ± 6 Ma.
Petrographic, electron microscope and electron microprobe investigation reveal multiple generations of manganese oxide precipitation.
The bone yields evidence for a probable cut and gauge marks (right upper part of the bone).
The picture was taken after the bone had undergone sampling for Zoo MS and before sampling for a DNA, radiocarbon, and stable isotope analysis.We decided to attempt to redate it, using a larger starting mass of bone powder.