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Publication date: Available online 18 September 2017Source:Journal of Archaeological Science Author(s): Albert JambonBronze Age iron artifacts could be derived from either meteoritic (extraterrestrial) or smelted (terrestrial) iron. This unresolved question is the subject of a controversy: are some, all or none made of smelted iron? In the present paper we propose a geochemical approach, which permits us to differentiate terrestrial from extraterrestrial irons. Instead of evaluating the Ni abundance alone (or the Ni to Fe ratio) we consider the relationship between Fe, Co and Ni abundances and their ratios. The study of meteoritic irons, Bronze Age iron artifacts and ancient terrestrial irons permit us to validate this chemical approach. The major interest is that non-invasive p-XRF analyses provide reliable Fe:Co:Ni abundances, without the need to remove a sample; they can be performed in situ, in the museums where the artifacts are preserved. The few iron objects from the Bronze Age sensu stricto that could be analyzed are definitely made of meteoritic iron, suggesting that speculations about precocious smelting during the Bronze Age should be revised. In a Fe:Co:Ni array the trend exhibited by meteoritic irons departs unambiguously from modern irons and iron ores. The trend of Ni/Fe vs Ni/Co in different analysis points of a single object corroded to variable extents provides a robust criterion for identifying the presence of meteoritic iron. It opens the possibility of tracking when and where the first smelting operations happened, the threshold of a new era. It emphasizes the importance of analytical methods for properly studying the evolution of the use of metals and metal working technologies in our past cultures.

Publication date: November 2017Source:Journal of Archaeological Science, Volume 87 Author(s): E.R. Crema, A. Bevan, S. ShennanSummed probability distributions of radiocarbon dates are an increasingly popular means by which to reconstruct prehistoric population dynamics, enabling more thorough cross-regional comparison and more robust hypothesis testing, for example with regard to the impact of climate change on past human demography. Here we review another use of such summed distributions – to make spatially explicit inferences about geographic variation in prehistoric populations. We argue that most of the methods proposed so far have been strongly biased by spatially varying sampling intensity, and we therefore propose a spatial permutation test that is robust to such forms of bias and able to detect both positive and negative local deviations from pan-regional rates of change in radiocarbon date density. We test our method both on some simple, simulated population trajectories and also on a large real-world dataset, and show that we can draw useful conclusions about spatio-temporal variation in population across Neolithic Europe.

Publication date: November 2017Source:Journal of Archaeological Science, Volume 87 Author(s): G.E. Fahy, C. Deter, R. Pitfield, J.J. Miszkiewicz, P. MahoneyStable carbon (δ13C) and nitrogen (δ15N) isotope studies of ancient human diet increasingly sample several skeletal elements within an individual. Such studies draw upon differences in bone turnover rates to reconstruct diet during different periods of time within an individual’s lifetime. Rib and femoral bone, with their respectively fast and slow remodelling rates, are the bones most often sampled to reconstruct shorter and longer term signals of diet prior to death. It is poorly understood if δ13C and δ15N vary between bone types within a single individual, or if this variation corresponds with bone turnover rate (BTR). Here, we determined δ13C and δ15N for ten different bones from ten adult human skeletons (n = 5 males; n = 5 females). Isotope values were compared to the rate that each bone remodeled, calculated from osteon population (OPD) density. Results reveal that isotope ratios varied within each skeleton (δ13C: max = −1.58‰; δ15N: max = 3.05‰). Humeri, metacarpals, and ribs had the highest rate of bone remodelling; the occipital bone had the lowest. A regression analyses revealed that higher rates of bone remodelling are significantly and negatively correlated with lower δ15N. Our results suggest that the occipital bone, with its slow rate of bone renewal, may prove useful for isotopic studies that reconstruct diet over longer periods of time within an individual’s lifetime. Isotope studies that compare individual skeletal elements between populations should standardize their methodology to bones with either a slow or fast turnover rate.

Publication date: October 2017Source:Journal of Archaeological Science, Volume 86 Author(s): Cheryl A. Makarewicz, Benjamin S. Arbuckle, Aliye ÖztanVertical transhumance is a crucial animal management strategy that provides livestock with fresh pasture on a seasonal basis while simultaneously expanding the scale of landscape usage by the pastoralist component of complex agro-pastoralist societies. Here, we explore the use of vertical transhumance in Anatolia during the Early and Middle Chalcolithic periods (6200–4500 cal BC), a time of socio-political transformation that presaged the rise of early state level societies in the region supported by a pronounced intensification in the exploitation of domesticated sheep and goats for their wool – a valuable commodity. We examine the carbon (δ13C) and oxygen (δ18O) composition of sequentially sampled tooth enamel from Chalcolithic sheep and goats from Köşk Höyük. The pattern of inverse cyclical isotopic variation characterized by high summer season δ18O values coincident with low δ13C values suggests livestock were moved to moist, high elevation pastures supporting 13C-depleted graze during the summer months or supplied with 13C-enriched fodder during the winter months. Inter-individual variation in absolute δ18O values and the amplitude of intra-tooth oxygen isotopic change reflects either differences in the spatial location of pastures, differences in the relative contribution of 18O enriched leaf water to caprine body water, or a combination of both. The incorporation of pasturing strategies involving vertical transhumance into livestock management systems, in conjunction with zooarchaeological evidence for increasing pastoral specialization and wool production at Köşk Höyük, suggests an intensification of smallstock production that provided important economic support for increasingly complex political landscapes.

Publication date: October 2017Source:Journal of Archaeological Science, Volume 86 Author(s): Vincent Bonhomme, Emily Forster, Michael Wallace, Eleanor Stillman, Michael Charles, Glynis JonesThe application of morphometric analysis in archaeobotany has the potential to refine quantitatively identifications of ancient plant material recovered from archaeological sites, most commonly preserved through charring due to exposure to heat. This paper uses geometric morphometrics, first, to explore variation in grain shape between three domesticated cereal species, einkorn (Triticum monococcum), emmer (Triticum dicoccum) and barley (Hordeum vulgare), both before and after experimental charring at 230 and 260 °C. Results demonstrate that outline analysis reliably reflects known variations in grain shape between species and differences due to charring observed in previous experimental work, and is capable of distinguishing the species, with near-perfect results, both before and after charring. Having established this, the same method was applied to different accessions of the same species, which indicated that three different grain morphotypes of einkorn and two, possibly three, of emmer could be identified in the uncharred material, and that at least two different morphotypes for each species could be distinguished even after charring at temperatures up to 260 °C. This opens up the possibility of tracking evolutionary change in crops, both chronologically and geographically, through morphometric analysis.

Publication date: October 2017Source:Journal of Archaeological Science, Volume 86 Author(s): Haifeng Liu, Wei Qian, Jianli Chen, Hongli Chen, Matthew L. Chastain, Michael R. NotisField investigation was carried out to study ancient cast iron smelting furnaces at 15 sites from Imperial China. Petrographic analyses were performed on furnace materials to study the development of metallurgical ceramics used on these furnaces. The results show that furnace materials developed from simple clay material to a composite structure made of stone and clay. During the period from the 4th C. BCE to the 3rd C. CE, rammed clay or stacked clay bricks were used to build the furnaces; from the 7th to the 13th C. CE, furnaces were predominantly made with a durable outer wall constructed from stone, while the refractory material that lined the inner surface of the stone wall was composed of clay, sand and gravel-sized rock fragments. In addition, this paper discusses some aspects of governmental organization, furnace and smelting technology, economics which might influence this development, and examines the relationship between ceramic technology and metallurgy in Imperial China.

Publication date: October 2017Source:Journal of Archaeological Science, Volume 86 Author(s): Fadi Hajj, Anne Poszwa, Julien Bouchez, François GuéroldDifferent approaches are used to study wood provenance, but most of them are based on tracers in wood that are generally controlled by climatic factors. The strontium isotopic ratio 87Sr/86Sr in trees and soils is related to the signature of the local bedrock. Despite being used in diverse archaeological studies, Sr isotopes have rarely been used to trace the provenance of archaeological wood and especially wood from shipwrecks. In addition, recent analytical advances have allowed the detection of mass-dependent fractionation of Sr isotopes during biogeochemical processes, as reflected in the variation of δ88/86Sr values between different environmental materials. The δ88/86Sr values could be used in conjunction with the 87Sr/86Sr isotope ratio to improve constraints on the sources of Sr in the archaeological materials being studied. This paper discusses the potential and limitations of using both of these Sr isotope ratios to trace the provenance of wood from shipwrecks. We review the 87Sr/86Sr and δ88/86Sr variations in rocks, waters, soils, plants and other living organisms and discuss how to determine the local Sr isotopic signature of potential sites. We also compile a list of known wood post mortem modifications in seawater. Possible implications in terms of the modification of the original Sr isotope ratios of wood during storage in seawater are illustrated through preliminary observations. This paper points out some limitations and perspectives for using Sr isotopes in provenancing wood from shipwrecks, and suggests future research to test and apply this approach for tracing the origin of archaeological wood.

Publication date: October 2017Source:Journal of Archaeological Science, Volume 86 Author(s): Manuel Domínguez-Rodrigo, Palmira Saladié, Isabel Cáceres, Rosa Huguet, José Yravedra, Antonio Rodríguez-Hidalgo, Patricia Martín, Antonio Pineda, Juan Marín, Clara Gené, Julia Aramendi, Lucia Cobo-SánchezA series of experimental cut marks have been analyzed by eleven taphonomists with the goal of assessing if they could identify similarly 14 selected microscopic variables which would identify those marks as cut marks. The main objective was to test if variable identification could be made scientifically; that is, different researchers using the same method and criteria making the same assessment of each variable. This experiment shows that even in researchers trained in the same laboratories and following the same protocols divergences in the perception of each variable are significant. This indicates that mark perception and interpretation is a highly subjective process. If this basic analytical stage is subjective, subjectivity permeates to a greater degree the higher inferential stages leading from mark identification to reconstruction of butchering behaviors based on mark frequencies, mark anatomical distribution, actor-effector-trace processes, and statistical interpretations of the stochastic mark-imparting butchering processes. Here, we emphasize that the use of bone surface modifications for behavioral interpretations remains a non-scientific endeavor because of lack of independent replicability of criteria and processes, divergences in how variables are selected and used and epistemologically flawed analogs. This constitutes a major call to taphonomy to engage in more scientific (i.e., objective) approaches to the study of bone surface modifications for taphonomic inference elaboration.

Publication date: October 2017Source:Journal of Archaeological Science, Volume 86 Author(s): Michelle Rae BebberThe addition of pottery additives (temper) provides both production-based benefits gained during the initial vessel formation phase, and performance-based benefits associated with post-firing vessel daily use. This paper presents the results of a controlled archaeological experiment designed to assess the opportunity costs associated with the addition of temper to clay during prehistoric pottery production sequences. Specifically, this study builds upon earlier research using material science methods to more broadly assess whether vessel strength is sacrificed by the addition of temper into the clay body. Standardized experimental ceramic test specimens, based directly upon petrographic analysis of archaeological samples from a regional context (South Central Ohio, USA) and produced using glacially-deposited illite-based clay, were subjected to mechanical strength tests using an Instron Series IX universal testing machine. The results demonstrate that there are indeed opportunity costs associated with temper addition: lost potential strength and reduced vessel use-life. Overall, untempered samples were significantly stronger than samples tempered with the most commonly used regional tempers—grit, limestone, and burnt shell—in terms of peak load and modulus of rupture. In other words, the results presented here suggest that prehistoric potters were losing the opportunity to create significantly stronger vessels in favor of the benefits that come with the addition of temper. Understanding of the existence, kind, and degree of opportunity costs that come with the addition of temper to clay emphasizes just how important the benefits of tempering must have been for the technology to be invented, experimented with, and ultimately so widely adopted.

Publication date: September 2017Source:Journal of Archaeological Science, Volume 85