J Archaeol Sci 31 (6)

In this paper the authors discuss some intrinsic constraints on the application of travelling wave models, derived from estimates of reproductive rates and of individual mobility, to the spatial dynamics of human dispersal events which have been documented in the archaeological record. There is significant uncertainty in radiocarbon dating of first occupation at different locations, and in the reconstruction of evolving population distributions from time-averaged archaeological distribution maps. The authors calculate some archaeological boundary conditions for the accurate estimation of travelling wave profiles and velocities, and demonstrate their significance for two archaeological case studies: the first peopling of the Americas, and the Neolithic transition in Europe.

A total of 101 cattle teeth and bones from thirteen archaeological sites between 1,000 to 9,000 years old were assessed for the presence of verifiable mitochondrial sequences. It was possible to reproducibly amplify and sequence mitochondrial control region DNA extracted from twelve of the samples. The results were compared with published extant data by constructing phylogenetic networks. The sequences obtained from the cattle specimens were either identical to the reference sequence for modern cattle or closely related to it. They included three sequences not previously documented.

Colour measurement was used as a means of characterizing ancient pottery. Tests which evaluated firing temperatures were performed on sherds subjected to a reducing step during the original firing. Results were not always successful in the evaluation of the maximum firing temperature, but seemed to provide useful information on the adopted firing conditions. The effect of primary and secondary calcite in the evaluation of firing temperatures was also studied; it appeared that the possibility of correctly estimating maximum temperatures of firing may not be affected by CaO contents up to about 5% in a sample fired under oxidizing conditions. Colour measurement further proved to be useful in discriminating between products obtained from different clays or differently processed clays. This may be achieved following the variation of colour coordinates with the temperature of refiring of archaeological sherds. Finally, it has been proved that the information provided by colour measurement may be correctly obtained by subjecting a single aliquot of sample to successive refiring cycles; this allows the use of colour measurement when only limited sampling is permitted.

This study looks at the residues of heated organic remains, usually called carbonized or charred remains, and focuses on the physical and chemical alterations, both as a function of temperature and time, that occur when the transformation of a polysaccharide-rich biomass is simulated in the laboratory. Peas (Pisum sativum) were heated at temperatures ranging from 130--700 °C under anoxic conditions and atmospheric pressure, during a maximum of 2 h. Changes in weight and the relative percentages of C, N, H and O were noted alongside modifications of the internal and external morphology. Vitrinite reflectance provided a tool to determine the heating temperature of the residues. The kinetics that determine the changes and modifications are discussed. The resulting solid products of the heating process can be conveniently considered in five phases, which fit the physical and chemical properties. The simulation provides a basis for the study of the formation processes, as applied in archaeology, after the so-called "carbonization" process.