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Publication date: Available online 31 January 2018Source:Journal of Archaeological Science Author(s): Janice Wood, Ben FitzhughResearch in the field of wound ballistics has identified three major types of penetrating trauma injuries that will affect wound severity of a projectile point into hard or soft tissues: puncture, incised, and lacerated. In this study, we report on dual ballistics experiments conducted to better understand the wounding mechanisms of three prehistoric projectile point classes made respectfully of polished bone, bifacially flaked stone, and composite antler inset with microblades. Each class of projectiles was launched into ballistics gelatin and into the carcass of a reindeer to explore the relative performance characteristics of each class in terms of tool durability and wound infliction. Our methods of evaluation included a detailed measurement of projectile attributes before and after penetration of both gelatin and carcass that were then compared using tip-metrics, penetration depth, and total interior wound area. Our results strongly suggest that the wounding potential differed significantly between projectile point classes and in turn, strongly influenced wound severity. We suggest that point mechanics may implicate a “prey specific” hunting strategy and propose that such analyses can help us better understand prehistoric hunter-gather behavior and technological variability.

Publication date: March 2018Source:Journal of Archaeological Science, Volume 91 Author(s): Alastair Key, Michael R. Fisch, Metin I. ErenPalaeolithic stone technologies have never been investigated in terms of how sharpness influences their ability to cut. In turn, there is little understanding of how quickly stone cutting edges blunt, how past populations responded to any consequent changes in performance, or how these factors influenced the Palaeolithic archaeological record. Presented here is experimental data quantitatively detailing how variation in edge sharpness influences stone tool cutting performance. Significant increases in force (N) and material displacement (mm) requirements occur rapidly within early stages of blunting, with a single abrasive cutting stroke causing, on average, a 38% increase in the force needed to initiate a cut. In energetic terms, this equates to a 70% increase in work (J). Subsequent to early stages of blunting we identify a substantial drop in the impact of additional edge abrasion. We also demonstrate how edge (included) angle significantly influences cutting force and energy requirements and how it co-varies with sharpness. Amongst other conclusions, we suggest that rapid reductions in performance due to blunting may account for the abundance of lithic artefacts at some archaeological sites, the speed that resharpening behaviours altered tool forms, and the lack of microscopic wear traces on many lithic implements.

Publication date: Available online 17 January 2018Source:Journal of Archaeological Science Author(s): Abidemi Babatunde Babalola, Laure Dussubieux, Susan Keech McIntosh, Thilo RehrenThe site of Igbo Olokun on the northern periphery of Ile-Ife has been recognized as a glass-working workshop for over a century. Its glass-encrusted crucibles and beads were viewed as evidence of secondary processing of imported glass until the high lime, high alumina (HLHA) composition of the glass was recognized as unique to the region. Archaeological excavations conducted at Igbo Olokun recovered more than twelve thousand glass beads and several kilograms of glass-working debris. Fifty-two glass beads from the excavated assemblage were analyzed by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) to understand the chemical characteristics of the Igbo Olokun glass beads in comparison with previously analyzed beads. The analyses affirm the prevalence of HLHA glass beads, and provide firm evidence of a new compositional group characterized by low lime, high alumina (LLHA); no imported soda-lime glass beads were among the analyzed samples. The evidence from crucibles indicates that LLHA glass was worked together with HLHA glass at Igbo Olokun and may have been made locally as part of the same technological tradition. Most likely, granitic sand with or without added calcium carbonate was used to produce these two types of glass, and colorants rich in MnO, Fe2O3, CuO, and CoO were intentionally added. Its occurrence in other West African societies, and the presence of some soda-lime glass beads in other sites in Ile-Ife suggest that Ife was involved in regional and inter-regional networks during the early to mid 2nd millennium AD and possibly earlier.

Publication date: January 2018Source:Journal of Archaeological Science, Volume 89

Publication date: February 2018Source:Journal of Archaeological Science, Volume 90 Author(s): Matthew D. Howland, Ian W.N. Jones, Mohammad Najjar, Thomas E. LevyCutting-edge photogrammetric techniques combined with traditional methods are a boon for archaeologists interested in performing spatial analyses. Low-altitude aerial photography (LAAP) combined with photogrammetric Image Based Modeling (IBM) comprise a workflow that allows for precise and accurate recording of both photographic and elevation data of archaeological sites with a great deal of speed and efficiency. Through these techniques, the researcher can create spatially-referenced orthophotos and digital elevation models (DEMs), which can serve as the basis for investigations into site formation processes. Due to the rapidity of the creation of these datasets, analysis of site formation processes can be completed over the course of hours or days. The results of such site formation studies can inform and guide further archaeological investigations of sites. This paper presents the application of a combined LAAP-IBM method to acquire GIS data, which serves as the basis for a case study of a new model of the effects of erosion on archaeological sites – a key factor in understanding site formation processes. These methods are applied to Khirbat Nuqayb al-Asaymir, a Middle Islamic site in southern Jordan, as a case study.

Publication date: February 2018Source:Journal of Archaeological Science, Volume 90 Author(s): Chris Loendorf, Lowell Blikre, William D. Bryce, Theodore J. Oliver, Allen Denoyer, Greg WermersArchaeologists have previously proposed several different measures of flaked stone raw material “quality”, but this variable has proven difficult to quantify, and the precise characteristics that improve performance remain unclear. This paper presents the results of controlled experiments that were designed to test projectile points made from stones with varying impact strength. By comparing an independent measure of strength with projectile point experimental data, our research suggests that this variable can be objectively measured, and it is a good predictor of some aspects of projectile tip function. Our results show that highly homogenous fine-grained materials with low impact strength (e.g., obsidian) perform well when penetrating elastic materials such as skin and muscle. These same materials, however, function poorly when penetrating more inelastic materials like rawhide, and they are substantially less durable.

Publication date: February 2018Source:Journal of Archaeological Science, Volume 90 Author(s): Rob WisemanThis article introduces a simple, intuitive model for the random accumulation of objects into groups, and the inverse process of random fragmentation.The model is used to explore metalwork hoards deposited during the British Bronze Age (2500–800 BC). Between 1997 and 2015, 174 hoards from England and Wales were reported to the Portable Antiquities Scheme. Three-quarters of those large enough to assess are a good match to the model. The model also predicts approximately 85–95% of bronze in circulation must have ended up in hoards. Key consequences are that most large hoards of the Late Bronze Age, and possibly also the Middle Bronze Age, must be the product of random accumulation and breaking, and that their burial must only have been temporary (otherwise the bronze economy in Britain would have collapsed). This runs counter to most contemporary explanations of bronze deposition, which stress selective deposition, votive offerings, status display, and meaningful behaviour.The same distribution appears in other archaeologically-significant distributions, such as administrative areas and field sizes.

Publication date: February 2018Source:Journal of Archaeological Science, Volume 90 Author(s): Ellery FrahmStudies of Northern Mesopotamian complex societies have long been predicated on ceramic wares, whereby ceramic variation is thought to reflect cultural variation. There is, however, an increasing appreciation for the role of imitation, itinerancy, and other phenomena in the distribution of ceramic styles. Much of this newfound nuance is due to chemical studies. Increasingly ceramics have been studied using portable X-ray fluorescence (pXRF). The utility of pXRF in ceramic research relies on being able to interpret the data in behaviorally meaningful ways. Thus, one approach to considering the efficacy of pXRF for ceramic studies proceeds from understanding the ways in which clays and tempers act as variables and influence the data in ways that reflect past behaviors. First, this study uses experimental replicas to exert systematic control over individual parameters (e.g., temper size, volume), allowing a better understanding of their influence. Second, this study considers Bronze Age wares at Tell Mozan in northeastern Syria. The experimental ceramics and Tell Mozan sherds are technological products that retain chemical evidence of choices made during their production. In the experimental ceramic set, a predicted phenomenon (e.g., the “dilution” effect from temper) occurred as expected, and elemental data differentiated clays and tempers selected for their manufacture. In the archaeological assemblage, elemental approaches established that distinctions between imports and locally made imitations are not always apparent by conventional means, and the use of pXRF is one way to overcome current shortcomings as well as contribute new insights.

Publication date: February 2018Source:Journal of Archaeological Science, Volume 90 Author(s): Andrés Tejero-Andrade, Denisse L. Argote-Espino, Gerardo Cifuentes-Nava, Esteban Hernández-Quintero, René E. Chávez, Alejandro García-SerranoChichén Itzá, located in the north-central portion of the Yucatán Peninsula, is one of the major pre-Hispanic cities established in the southern lowlands of Mexico. The main objective of this investigation was to “unveil” the interior of the pyramid of El Castillo, also known as the Temple of Kukulkan, an emblematic structure in this archaeological site. To that end, 828 flat electrodes were deployed around each of the 9 bodies that compose the pyramid, including the base of the structure. A dataset consisting of 37,548 observations was obtained. A precise topographic control for each electrode was carried out and introduced in the inversion model. The mathematical process to compute a final 3D model was made possible by taking 9 observation levels (33,169 measurements) into account, due to computational limitations. The results showed the existence of two older pyramids within the main Mayan building and provided important information regarding our understanding of this Mayan civilization. Future archaeological studies in the older substructure could reveal information about early settlement on this site, its evolution in time and its cultural influences.

Publication date: Available online 22 December 2017Source:Journal of Archaeological Science Author(s): M. Radivojević, J. Pendić, A. Srejić, M. Korać, C. Davey, A. Benzonelli, M. Martinón-Torres, N. Jovanović, Ž. KamberovićThe aesthetic appearance of metals has long been recognised in archaeometric studies as an important factor driving inventions and innovations in the evolution of metal production. Nevertheless, while studies of ancient gold metallurgy are well supported by modern research in colour characteristics of gold alloys, the colour properties of major prehistoric copper alloys, such as arsenical copper and tin bronzes, remain either largely understudied or not easily accessible to the western scholarship. A few published studies have already indicated that alloying and heat treatment change the colours of copper alloys, although they are mainly based on examples of prehistoric tin bronze objects and experimental casts. Here we present a procedure for building the Cu-As-Sn ternary colour diagram, starting with experimental casting of 64 binary and ternary alloys in this system. We used two types of information to produce two different ternary colour diagrams: one based on photographs of the samples, and the other based on the colorimetric measurements. Furthermore, we developed a procedure for creating a graphic representation of colours in the Cu-As-Sn ternary diagram using QGIS. As an initial case study, we plotted the composition of the world’s earliest tin bronze artefacts; the graphic representation further supports claims about the importance of a golden hue for their invention and demand, c. 6500 years ago. We argue that the presented colour diagrams will find wide use in future investigations of aesthetics of prehistoric copper alloys.