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Publication date: October 2016Source:Journal of Archaeological Science, Volume 74

Publication date: November 2016Source:Journal of Archaeological Science, Volume 75 Author(s): Gaygysyz Jorayev, Karol Wehr, Alfonso Benito-Calvo, Jackson Njau, Ignacio de la TorreThis paper presents the first aerial mapping of Olduvai Gorge (Tanzania) using Unmanned Aerial Vehicles and photogrammetric techniques, to provide a detailed digital cartographic basis for this world-renowned paleoanthropological site. The survey covered an area of 32 km2 of Olduvai Gorge, and through the use of aerial photos and ground control points from Global Navigation Satellite Systems, an orthomosaic and Digital Surface Model, with a higher than 5 cm/pixel ground resolution, were produced. The Digital Surface Model was then denoised to calculate a Digital Elevation Model, and a high-resolution imaging model of Olduvai Gorge was generated. A preliminary morphometric characterization using Geographic Information Systems shows the potential of this approach when analysing multiple topographic variables in large areas of paleoanthropological relevance, including production of a new map template for Olduvai Gorge and new data for the investigation of sedimentary and tectonic processes. These results constitute one of the first attempts to obtain high quality imagery from large geographic areas amenable to Early Stone Age research, and introduce new workflows for the creation of Digital Elevation Models. Overall, the digital dataset produced is intended to support archaeological and geological investigation in this area, and provide new monitoring tools for the conservation of cultural heritage.

Publication date: November 2016Source:Journal of Archaeological Science, Volume 75 Author(s): G. Artioli, I. Angelini, P. Nimis, I.M. VillaThe Southeastern Alps were an important source of copper metal in prehistory, at least from the Eneolithic and through the Bronze Age, as documented by the abundant and substantial presence of smelting slags. Evidence of mining activity is scarce, because of limited ad hoc investigation and because of the subsequent systematic erasing by post-Medieval exploitation. Moreover, until recently the profusion of archaeometallurgical and archaeological investigations focusing on the prehistoric exploitation of Northern Alpine, Central European, and Balkan ore sources has somehow obscured the early role of the Italian Southern Alps as a major copper producing area. The recent advances in the systematic characterization of the copper ores in the Southeastern Alps (including Alto Adige, Trentino, Veneto, and nearby regions) by lead isotope analysis, supported by mineralogical and geochemical interpretation, offer now the appropriate tools to re-evaluate the extent of prehistoric mining and the local patterns of ore exploitation. The developed database is a powerful tool to identify the metal derived from local production. It is suggested that (1) based on the abundance and chronological distribution of smelting slags evidence, two major periods of mining exploitation took place, the first in the middle of the 3rd millennium BC and the second during the Late Bronze Age; and (2) based on the discrimination of copper sources and the available analyses, most of the metal circulating in Northern Italy and in the greater Po Valley region was actually produced from Southern Alpine ores.

Publication date: November 2016Source:Journal of Archaeological Science, Volume 75 Author(s): David Killick, Duncan Miller, Thomas Panganayi Thondhlana, Marcos Martinón-TorresWe report chemical, petrographic and metallographic studies of copper ores and slags recovered during sporadic surface surveys and excavations over the past fifty years in the Phalaborwa and Murchison Range areas of the northern Lowveld of South Africa. The copper slags around Phalaborwa have unusual mineral assemblages, attributable to the unique geochemistry of the main ore body, the Phalaborwa Complex, where copper minerals were mined from a carbonatite composed of magnetite, calcite and apatite. Strongly reducing conditions had to be avoided to minimise contamination of the copper with iron and phosphorus. As the copper ores contain almost no silicates, silica/alumina flux was added to produce slag. The Precambrian zinc-copper ores of the Murchison Range were also smelted, but during smelting any zinc that was not volatilised was taken up by minerals in the slag, so brass was not produced.

Publication date: November 2016Source:Journal of Archaeological Science, Volume 75 Author(s): Nicolas GauthierI examine the relationship between the spatial pattern of aridification in the northeastern Mediterranean ca 8600 years ago and the spread of Neolithic farmers into the region surrounding the Aegean Sea. I use a generalized additive model to downscale winter rainfall from a state-of-the-art paleoclimate simulation. The model performs well at reproducing the present-day pattern of rainfall in the northeastern Mediterranean, and it generates physically-interpretable estimates of past rainfall consistent with global and regional proxy records of early Holocene climate. Comparing modeled rainfall with Neolithic settlement patterns reveals spatially-heterogeneous regional impacts of this period of global aridification. Only the humid regions of the Aegean coast experienced major drought, while more inland zones temporarily experienced more rainfall. The result of this spatially heterogeneous climate event was, conversely, more homogeneous regional rainfall. Neolithic colonists from southwest Asia would have encountered new landscapes with a more familiar, and predictable, precipitation regime.

Publication date: October 2016Source:Journal of Archaeological Science, Volume 74 Author(s): Kyle A. Knabb, Yigal Erel, Ofir Tirosh, Tammy Rittenour, Sofia Laparidou, Mohammad Najjar, Thomas E. LevyThe environmental impact of mining and metallurgy is an issue that has affected societies in the ancient Near East over the past 8000 years. We present the results of a multidisciplinary project using agricultural sediments from ancient terraces as a cultural archive of environmental pollution and land use in the copper ore-rich Faynan valley of southern Jordan. Due to the simultaneous production of agricultural goods and copper metallurgy throughout the last 6000 years in the valley, environmental pollution and its consequences for human health have been considered as a factor in settlement abatement. Sediments from two farming terrace systems adjacent to the major mining and smelting locales were analyzed. The sediment analyses included metal concentrations, lead-isotopes and phytolith analysis, and OSL dating. Although measurable concentrations of lead and other heavy metals persist in ancient metallurgical waste piles, our investigations found minimal evidence for contamination in the adjacent terrace systems. Based on these results, we argue that the occurrence of environmental pollution in the Faynan valley is highly variable, and that the distribution of heavy metals resulted from a combination of natural and cultural factors, including persistent landscape features that helped contain the most polluted metallurgical deposits. These findings are significant for understanding the processes of landscape change and human impacts on desert environments, including the ways in which past human actions have negatively affected the environment, as well as preserved and protected the environment from further degradation.

Publication date: October 2016Source:Journal of Archaeological Science, Volume 74 Author(s): Matt GrovePrompted by the results of a series of recently published simulation models, there is an increasing tendency for archaeologists to invoke demographic variables as explanations for changes in the sophistication or complexity of material culture. Whilst these models are undoubtedly valuable, this paper draws attention to persistent failings in the interpretation and application of these models by archaeologists. Despite having quite different effects, variables such as population size and population density are often used interchangeably; and whilst increasing mobility has an effect broadly equivalent to that of increasing population density, it is rarely given sufficient weight in archaeological explanations of cultural change. The analyses reported here develop a series of new simulations based on the ideal gas model, allowing for an explicit prediction of the encounter rate – the variable for which population density and mobility are proxies, and which ultimately governs the rate of cultural transmission. This model supports the predictions of earlier studies on the effects of population density and mobility, but suggests that population size will have no effect on rates of cultural transmission. These simulations are coupled with analyses that demonstrate a reciprocal correlation between population density and mobility in a large hunter-gatherer dataset. Given this correlation, it is argued that archaeological inferences about cultural transmission based on just one of these variables are unlikely to be valid. These findings are discussed in the context of previous research, and it is suggested that future studies would gain greater explanatory power by focusing explicitly on the social network structures likely to have characterised a particular archaeological population.

Publication date: October 2016Source:Journal of Archaeological Science, Volume 74 Author(s): Marianne Mödlinger, Benjamin SabatiniThis study revaluates reported cases of prehistoric As-Cu objects with ‘silvery surfaces’, which are usually interpreted as the result of inverse segregation. Further possible explanations for such surfaces, such as an arsenic-rich α-solid solution, cementation, or post-depositional precipitation, are discussed. The segregation of arsenic was studied in As-Cu ingots produced in chill cast moulds at several compositions, which underwent surface treatment with an NaCl solution. The microstructure and surfaces of the As-Cu alloys were analysed using optical microscopy and SEM-EDXS. Special note of out-of-equilibrium As-Cu phases are discussed, as well as a comparison of inverse segregation to all other means of achieving surface silvering.

Publication date: October 2016Source:Journal of Archaeological Science, Volume 74 Author(s): Marianne Mödlinger, Benjamin SabatiniThis study revaluates reported cases of prehistoric As-Cu objects with ‘silvery surfaces’, which are usually interpreted as the result of inverse segregation. Further possible explanations for such surfaces, such as an arsenic-rich α-solid solution, cementation, or post-depositional precipitation, are discussed. The segregation of arsenic was studied in As-Cu ingots produced in chill cast moulds at several compositions, which underwent surface treatment with an NaCl solution. The microstructure and surfaces of the As-Cu alloys were analysed using optical microscopy and SEM-EDXS. Special note of out-of-equilibrium As-Cu phases are discussed, as well as a comparison of inverse segregation to all other means of achieving surface silvering.

Publication date: October 2016Source:Journal of Archaeological Science, Volume 74 Author(s): Morgan C.F. Disspain, Sean Ulm, Christopher Izzo, Bronwyn M. GillandersThe morphological and chemical properties of fish calcified structures provide excellent environmental and anthropogenic proxies; however, pre-depositional handling may alter these properties, confounding interpretations. This study examines the effects of some traditional processing and cooking methods on the morphological and chemical properties of modern fish otoliths (ear bones), vertebrae, and scales using an experimental approach. Whole mulloway (Argyrosomus japonicus) were treated using a range of techniques, including boiled in freshwater and saltwater; roasted directly on a fire and wrapped in clay; salted; and completely burnt. Samples were also obtained from untreated fish as controls for comparison. Otoliths, vertebrae and scales from the samples were subjected to morphological, trace element (7Li, 23Na, 24Mg, 55Mn, 86Sr, 138Ba, 208Pb, and 65Zn all ratioed to 43Ca) and stable isotope analyses (otoliths and vertebrae – inorganic δ13C and δ18O; scales – organic δ13C and δ15N). Results reveal disparities in the chemistry and morphology of otoliths and vertebrae processed in different ways. The otolith and vertebrae carbonate δ18O values were lower in samples that experienced heating; burnt samples differed significantly from the control samples. Otolith and vertebrae trace elements were largely unaffected by the treatments relative to the controls; however, some individual elements within the burning and salting groups varied significantly. The impacts observed in the fish scales were less substantial. Results provide a basis for evaluating the suitability of archaeological samples for analysis. We recommend avoiding the use of heated samples. Findings highlight the need to conduct palaeoenvironmental reconstructions based on chemistry and stable isotope data of archaeological remains with caution.