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<abstract xmlns="http://eprints.org/ep2/data/2.0">This paper considers the recent radiometric dating (&#13;
14&#13;
C-AMS, TL, ESR) of 76 late Middle and early Upper&#13;
Paleolithic samples from Ortvale Klde Rockshelter, located in the Republic of Georgia. We present&#13;
a critical evaluation of each date based on its stratigraphic and archaeological context, its pretreatment&#13;
and contamination history, and its resulting accuracy and precision, the goal being to establish a sound&#13;
chronology for the site. Only by systematically identifying aberrant dates within a data set and isolating&#13;
them from further analysis can we hope to understand cultural and biological phenomena on an accurate&#13;
temporal scale. Based on the strict discard protocol outlined here, we omit 25% of the dated samples from&#13;
the analysis. The remaining data speak to the lengthy tenure of Neandertals in the region, but also to&#13;
their relatively rapid demise and the establishment of modern human populations w38–34 ka&#13;
14&#13;
CBP&#13;
(42–39 ka cal BPHulu). We compare these chronometric data with those from the neighboring sites of&#13;
Bronze and Dzudzuana caves, as well as Mezmaiskaya Cave, located in the northern Caucasus. While the&#13;
lack of key contextual information limit our ability to subject these other data sets to the same critical&#13;
evaluation procedure, they provide the first interregional temporal assessment of the Middle to Upper&#13;
Paleolithic ‘‘transition,’’ the results of which suggest an initial expansion of modern humans into the&#13;
southern Caucasus followed by expansion along the Black Sea coast and into the northern Caucasus.</abstract>
