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Publication date: April 2018Source:Journal of Archaeological Science, Volume 92 Author(s): Lara Maritan, Paola Iacumin, Andrea Zerboni, Giampiero Venturelli, Gregorio Dal Sasso, Veerle Linseele, Sahra Talamo, Sandro Salvatori, Donatella UsaiIn prehistoric hunter-gatherer-fisher communities, demographic growth and a more sedentary life-style are usually associated with locally concentrated food resources. Technologies believed to have been employed for preserving excess food resources include, among many others, salting, smoking, and/or sun-drying of fish and meat. However, direct proof of salting is often lacking, as salt is highly soluble. We present here the first robust evidence of the earliest known examples of fish salting from Middle Mesolithic structures at an archaeological site in Central Sudan (7th millennium BC). A multidisciplinary approach was applied, including a contextual geoarchaeological study (field analysis; micromorphological and scanning electron microscopy), a mineralogical-microstructural analysis of salt crystallization (X-ray diffraction, scanning electron microscopy), and a chemical analysis of salt concentration (ionic chromatography) in the soil in which salted fish bones have been found. The results indicate that salting fish with the aim of preserving it was common at the site of Al Khiday since the Middle Mesolithic and this habit cannot be related to post-depositional precipitation due to aridification of the area. A clear-cut emphasis on fishing characterized the economy of the human population of the time. This foraging system, together with salting and storing fish seems to be closely connected with its nearly sedentary status.

Publication date: April 2018Source:Journal of Archaeological Science, Volume 92 Author(s): Xavier Rubio-Campillo, Jean-Marc Montanier, Guillem Rull, Juan Manuel Bermúdez Lorenzo, Juan Moros Díaz, Jordi Pérez González, José Remesal RodríguezThe creation of the Roman Empire promoted the connectivity of a vast area around the Mediterranean sea. Mobility and trade flourished over the Roman provinces as massive amounts of goods were shipped over thousands of kilometres through sea, rivers and road networks. Several works have explored these dynamics of interaction in specific case studies but there is still no consensus on the intensity of this connectivity beyond local trade.We argue here that the debate on the degree of large-scale connectivity across the empire is caused by a lack of appropriate methods and proxies of economic activity. The last years have seen an improvement on the availability of evidence as a growing amount of datasets is collected and published. However, data does not equal knowledge and the methods used to analyse this evidence have not advanced at the same pace.A new framework of connectivity analysis has been applied here to reveal the existence of distinctive trade routes through the provinces of the Western region of Rome. The amphora stamps collected over more than a thousand sites have been analysed using quantitative measures of similarity. The patterns that emerge from the analysis highlight the intense connectivity derived from factors such as the spatial closeness, presence of military units and the relevance of the Atlantic sea as a main shipping route.

Publication date: April 2018Source:Journal of Archaeological Science, Volume 92

Publication date: Available online 9 March 2018Source:Journal of Archaeological Science Author(s): W. Powell, R. Mathur, A.H. Bankoff, J. John, O. Chvojka, M. Tisucká, A. Bulatović, V. FilipovićWe present a detailed response to the critique by Mr. Jansen of the paper “Digging Deeper: Insights into Metallurgical Transitions in European Prehistory through Copper Isotopes”. When we consider Cu isotope ratios of European Eneolithic and Early Bronze Age artifacts in the context of their local geological settings, climates, and archaeological contexts, Mr. Jansen’s hypothesis that 63Cu enrichment results from the adoption of fahlore ores is untenable. In both Serbia and Central Europe, the earliest copper production is associated with 65Cu-enriched ores and subsequently produced artifacts yield lower ranges δ65Cu. This shift in Cu isotopic composition correlates with the initial use of predominantly hypogene ores, not with variations in their trace element content. Essentially the expanded dataset supports the conclusions that were presented in the original paper—Cu isotopes are an effective means of delineating the transition from oxide-based smelting to methodologically more complex smelting of sulphide ores in prehistoric Europe with its relatively limited production and trade. Mixing did not mask the critical Cu isotope signatures in this setting. Therefore, Cu isotope compositions of artifacts can be used to interpret the mineralogical character of the ores from which they were produced, regardless of their provenance, as long as trade networks remained within a region of similar climatic history.

Publication date: May 2018Source:Journal of Archaeological Science, Volume 93 Author(s): Simon Hammann, Lucy J.E. CrampThe uptake of cereal agriculture in the Neolithic is one of the most important processes in later human prehistory. However, in many parts of Europe, early evidence from pollen or macrofossils is scarce or inconclusive, and there are considerable ambiguities about timing, intensity and the mode of transition to agriculture in these regions.An alternative approach is organic residue analysis, a technique that targets lipids preserved in the walls of unglazed ceramic pots used for storage and processing of foodstuffs. By analysing the molecular and isotopic composition of absorbed lipid residues, many different food items and processing techniques can be detected and distinguished. However, this approach is by-and-large limited to animal-based food sources, and despite their importance, many plant-based food items including cereals are currently not accessible with this approach.For a better understanding of the behaviour of cereal lipids, cooking experiments were conducted and the uptake of cereal-specific compounds such as alkylresorcinols and plant sterols into the ceramic matrix was investigated using a new sensitive method based on GC-Q-ToF-MS. Furthermore, changes in the lipid composition through post-burial degradation was assessed by incubation of potsherds dosed with cereal lipids at 35 °C in compost. The cooking experiments showed that only small quantities of cereal lipids are liberated, but additional lipid sources (meat) can increase the transfer of cereal biomarkers into the ceramic matrix. Anoxic degradation conditions allowed for twentyfold higher levels of alkylresorcinols and twofold higher levels of plant sterols after 20 weeks compared to oxic conditions. Therefore, samples from anoxic burial environments should be targeted and high sensitivity methods are a necessity to detect the trace amounts of cereal-specific biomarkers. To test the applicability of these biomarkers for archaeological pottery, organic residues from ten coarse ware vessels from an anoxic burial context at Vindolanda were analysed. Plant sterols and stanols were detected in three sherds, and two of the sherds also contained traces of alkylresorcinols.

Publication date: Available online 7 March 2018Source:Journal of Archaeological Science Author(s): Moritz JansenCu isotope characterization of copper-based artifacts is a powerful tool used in recent decades to investigate the types of ore smelted in ancient metal production. Within a larger sample set, Powell et al. (2017) have identified a shift from positive δ65Cu values obtained for Eneolithic artifacts in the Balkans (5000–3600 BC) to more moderate and negative δ65Cu values of Bronze Age artifacts (2500–1000 BC), with a so-called “copper hiatus” between these two periods. Powell et al. concluded that accessible oxidized ore sources in this region were totally exhausted by the end of the Eneolithic period, directly leading to a “hiatus” in copper production. After the “hiatus”, starting with the Early Bronze Age, they proposed that sulfide ores were smelted using the Mitterberg process. The current paper addresses some weaknesses of the arguments put forth by Powell et al. and instead argues that Cu isotope ratios must be jointly considered with additional archaeometallurgical and archaeological investigations. Selective changes in preference for metal alloys likely affected the Cu isotope composition. Metallurgical operations using distinct Cu isotope reservoirs can alter the univariate Cu isotope ratio (65Cu/63Cu). Key points that must be considered are the transition from pure copper in the Eneolithic to arsenical copper in the Bronze Age, the co-smelting of distinct ore types, and the co-melting of metals derived from multiple smelting operations or from re-used metal artifacts. Moreover, there is no archaeological evidence for the Mitterberg smelting process in the Balkans during the Early Bronze Age.

Publication date: May 2018Source:Journal of Archaeological Science, Volume 93 Author(s): Eileen Jacob, Diletta Querci, Miguel Caparros, Cecilio Barroso Ruiz, Thomas Higham, Thibaut DevièseThe collagen component of ancient bones is routinely isolated for radiocarbon dating and stable isotope studies. However, it is impossible to tell the state of collagen preservation from visual inspection of bones. At the Oxford Radiocarbon Accelerator Unit (ORAU), the percent nitrogen by weight (%N) of a ∼5 mg sample of bone powder is measured on a mass spectrometer and used as a proxy for protein content. A previous study showed that samples with %N > 0.76 are considered likely to produce sufficient collagen for radiocarbon dating (Brock et al., 2010b). However, the extent of variation between bone %N and collagen yield is unclear, as is the intra-bone variation in %N. Here, we report a series of tests performed on Palaeolithic bones known to have variable collagen preservation. This new study shows significant variation in %N within the same bone and that there is sometimes a lack of correlation between %N and collagen yield. These results suggest that for bone samples from difficult environments or from Pleistocene contexts, it may be worth sub-sampling for %N in different locations of the bone (if possible) and then attempting to extract collagen from marginally preserved bones (%N around 0.2–0.7%), as they may still yield sufficient collagen for isotope and dating studies.

Publication date: May 2018Source:Journal of Archaeological Science, Volume 93 Author(s): Daniel Contreras, Joel Guiot, Romain Suarez, Alan KirmanAssessing the implications of paleoclimatic and paleoenvironmental data at temporal and spatial scales that would have directly intersected with human decision-making and activity is a fundamental archaeological challenge. This paper addresses this challenge by presenting a spatial and temporal downscaling method that can provide quantitative high-spatio-temporal-resolution estimates of the local consequences of climatic change. Using a case study in Provence (France) we demonstrate that a centennial-scale Mediterranean-wide model of Holocene climate, in conjunction with modern geospatial and climate data, can be used to generate explicit and solidly-grounded monthly estimates of temperature, precipitation, and cloudiness at landscape scales and with annual resolution, enabling consideration of climate variability at human scales and meeting the data requirements of socioecological models focused on human activity. While the results are not reconstructions – that is, particular values are single realizations, consistent with the coarse-grained data but not individually empirically derived nor unique solutions – they provide a more suitable basis for assessing the human consequences of climate change than can coarse-grained data.

Publication date: May 2018Source:Journal of Archaeological Science, Volume 93 Author(s): Michael J. Plank, Melinda S. Allen, Reno Nims, Thegn N. LadefogedEstablishing whether pre-industrial societies caused significant harvesting impacts on fish stocks is often hindered by the paucity of historic evidence. Some archaeological assemblages contain information on the sizes and/or species of individuals in the catch, but this does not provide any direct evidence on the absolute size of the catch or comparative metrics. We develop a method for using size-frequency data to infer the intensity of fishing and the size-selectivity of the fishing gear in use. The model allows quantitative estimates to be made for the depletion of snapper populations relative to the unexploited pre-human biomass. We evaluate this method using six modern and five archaeological datasets from northern New Zealand for a key commercial and artisanal species, Australasian snapper or silver seabream (Pagrus auratus). Our method uses two models for the size selectivity of fishing: one S-shaped, representing mobile fishing gear such as trawls or seines, and one dome-shaped, representing static fishing gear, such as hooks, longlines, or gillnets. The results show that the estimated fishing intensity is lower, and the size of fish being caught is larger, in the archaeological datasets than in the modern datasets, as might be expected. Nevertheless, some of the archaeological datasets show evidence that is consistent with substantial resource depression and depletion of the largest fish in the population, while others suggest only light exploitation. The method allows the five archaeological cases to be rank ordered in terms of exploitation pressures and the relative orderings are further assessed using independent information on site chronology, stratigraphy, and recovery procedures (i.e., screen size). Other factors that can affect size-frequency data are briefly considered, but require additional environmental and taphonomic data that are not currently available. The results provided by our new method support the hypothesis that the depletion of large fish and capture of progressively smaller ones occurred in the pre-European era, albeit in spatially localized areas and at a much less severe level than in modern times. The model results also help identify potential biases in the archaeological assemblages and directions for further research.

Publication date: May 2018Source:Journal of Archaeological Science, Volume 93 Author(s): E. Kotoula, D.W. Robinson, C. BedfordThis paper deals with the documentation, and virtual visual analysis of pictographs using interactive relighting, digital image enhancement techniques and diagrammatic representations. It discusses areas of interest for the analysis of low surface detail, large and geometrically complex superimposed pictographs. The synergy of reflectance transformation imaging (RTI) and decorrelation stretch (DS) aimed to improve the study of superimposition via the enhanced visualization of the surface morphology, dominant features, paint characteristics and layering. Additionally, diagrammatic representations of the results of the image-based analysis provided a valuable tool for interpretation and integration of the diverse dataset from the ongoing research in the Pleito Cave in California. This method allows revisiting unresolved hypotheses concerning the site by unpacking chemical and visual data in superimposed sequences.