Modern and early-middle Holocene shells of the freshwater mollusc Unio, from Çatalhöyük in the Konya Basin, Turkey: preliminary palaeoclimatic implications from molluscan isotope data

Carbon and oxygen isotope ratios in the shells of the freshwater Unio mollusc yield information on the isotopic composition of the water in which the shell was formed, which in turn relates to climatic conditions prevailing during the bivalves’ life span. Here we analysed shells from one modern Unio, from a modern lake shore in Anatolia, and 4 subfossil Unio shells from Çatalhöyük (dated between 7200 BC and 5000 BC, Neolithic and Chalcolithic periods). Sequential carbon and oxygen isotope analysis along the surface of the shells provides information on seasonal or shorter-term variability of lake waters during the lifetime of the organisms. δ¹⁸O values of the modern shell are consistent with it being collected from a dammed portion of the Seyhan River that does not undergo intensive summer evaporation. This is in contrast to many of the surface water bodies in Anatolia which suffer extensive evaporation in the arid summers. δ¹⁸O values of the subfossil shells from the Çatalhöyük middens indicate that the bivalves came from lakes which evaporated extensively during the summer months but were replenished by high winter rainfall, suggesting that the subfossil shells lived in relatively small lakes or ponds. Stable isotope analysis along the growth of freshwater bivalves is one of the few methods for investigating seasonal water fluctuations in the past. These results may alter current interpretations on the environment of Çatalhöyük during the Neolithic, although more work is needed to confirm these initial findings.     

Evaluating the Potential of Semi-Automated Image Analysis for Delimiting Soil and Sediment Layers

ABSTRACT

Established methods for delineating anthropogenic and natural strata during fieldwork are based on the visual and tactile perception of excavators. Modern image analysis techniques can help to ensure objectivity and reproducibility when documenting sections and plana. Within this study we examine the unsupervised classification of digital images as a technique for delimiting layers and identifying stratigraphic features. Assessing the potential of this approach, we exemplarily captured soil profiles with high-contrast stratigraphy, located in the area of a historical vineyard (Brandenburg, Germany). Reproducible analyses were carried out using open-source software, allowing for the future advancement of the methodology utilized and providing a basis for the analysis of more complex stratigraphic sequences. We compare clustering results of high-resolution RGB and hyperspectral images (470–830?nm, 37 bands). Multiple pre-processing and processing steps are carried out to evaluate their influence. Our results render the semi-automatic analysis of RGB images helpful for stratigraphic interpretation.     

A flock of sheep,goats and cattle: ancient DNA analysis reveals complexities of historical parchment manufacture

Parchments comprise one of the most common and valuable sources of archaeological and historical data. Previous studies have shown that parchment also preserves genetic data. These data could be valuable for population studies, to understand past animal husbandry, the development of breeds and varieties and to comment on the provenance of parchments. To improve our understanding of DNA contained in parchments, we analysed genetic data, including both mitochondrial and autosomal loci, from 18th to 19th century English parchments which stable isotope analysis had indicated were well-preserved. DNA results were unexpected. All but one of the parchments produced multiple sequences matching several different species. Ion beam analysis ruled out surface treatments of the parchments (including ink and animal glues) as the origin of these multiple sequences. Our results suggest that the DNA content of parchment is more complex than previous research has suggested and that multiple stages of parchment manufacture, treatment and storage are preserved in parchment DNA extracts.