Prof Christopher Ramsey

Abstract:

Single and multiphase models have been used extensively in construction of chronologies. We model more gradual transition between phases with a trapezoid model since it better reflects the nature of the information that goes into the model prior. We find that a simple trapezoid model has a bias that does not reflect prior knowledge, and thus propose an addition of a noninformative element to the prior. We also present an alternative parameterization, which transforms the current abrupt transition model into a model that allows for gradual changes. The addition of a noninformative prior ensures model flexibility. We evaluate these Bayesian models using 2 case studies. © 2012 by the Arizona Board of Regents on behalf of the University of Arizona.

Abstract:

Egypt has some of the oldest written records and extended lists of named rulers. But radiocarbon dates have only fulfilled expectations 66 per cent of the time. So why haven't the two types of dating made a better match? The authors provide a dozen excellent reasons, which will sound the alarm among researchers well beyond Dynastic Egypt. © Antiquity Publications Ltd.

Abstract:

The German site of Geißenklösterle is crucial to debates concerning the European Middle to Upper Palaeolithic transition and the origins of the Aurignacian in Europe. Previous dates from the site are central to an important hypothesis, the . Kulturpumpe model, which posits that the Swabian Jura was an area where crucial behavioural developments took place and then spread to other parts of Europe. The previous chronology (critical to the model), is based mainly on radiocarbon dating, but remains poorly constrained due to the dating resolution and the variability of dates. The cause of these problems is disputed, but two principal explanations have been proposed: a) larger than expected variations in the production of atmospheric radiocarbon, and b) taphonomic influences in the site mixing the bones that were dated into different parts of the site. We reinvestigate the chronology using a new series of radiocarbon determinations obtained from the Mousterian, Aurignacian and Gravettian levels. The results strongly imply that the previous dates were affected by insufficient decontamination of the bone collagen prior to dating. Using an ultrafiltration protocol the chronometric picture becomes much clearer. Comparison of the results against other recently dated sites in other parts of Europe suggests the Early Aurignacian levels are earlier than other sites in the south of France and Italy, but not as early as recently dated sites which suggest a pre-Aurignacian dispersal of modern humans to Italy by ~45000 cal BP. They are consistent with the importance of the Danube Corridor as a key route for the movement of people and ideas. The new dates fail to refute the . Kulturpumpe model and suggest that Swabian Jura is a region that contributed significantly to the evolution of symbolic behaviour as indicated by early evidence for figurative art, music and mythical imagery. © 2012 Elsevier Ltd.

Abstract:

The sanctuary on the island of Keros takes the form of deposits of broken marble vessels and figurines, probably brought severally for deposition from elsewhere in the Cyclades. These acts of devotion have now been accurately dated, thanks to Bayesian analyses of the contemporary stratigraphic sequence on the neighbouring islet of Dhaskalio. The period of use-from 2750 to 2300 cal BC-precedes any identified worship of gods in the Aegean and the site is among the earliest ritual destinations only accessible by sea. The authors offer some preliminary thoughts on the definition of these precocious acts of pilgrimage. © Antiquity Publications Ltd.