Quantifying flake scar patterning on cores using 3D recording techniques

A key feature of stone artefact morphology is the arrangement and patterning of negative flake scars left on flakes and cores. Scar patterning is often treated as a rough guide to identifying methods of core preparation and reduction and usually forms a key component of lithic typologies and other systems of analysis. However, scar patterns are often complex and difficult to capture using traditional measurement or classificatory techniques, particularly where flakes are thick and irregular, or where cores are flaked on many sides from a number of platforms. Three-dimensional analysis of flake scars is now more feasible using digital 3D surface scanning technologies, or using three-dimensional measurement tools such as the Microscribe-3DX which is now widely used in biological geometric morphometric studies more generally [D.C. Adams, F.J. Rohlf, D.E. Slice, Ital. J. Zool., 71 (2004) 5–16; F.J. Rohlf, L.F. Marcus, Trends Ecol. Evol. 8 (1993) 129–132. [1 and 34]]. This paper develops a mathematical formula for describing scar patterning using vectors calculated from the start and end points of flake scars recorded in three dimensions.     

How flakes shatter: a critical evaluation of quartz fracture analysis

Despite its worldwide use as a stone tool raw material, quartz is known to be a difficult material for archaeologists. The main reason for this is the tendency of quartz flakes to fragment during detachment, which complicates the use of traditional lithic analyses. In this article we present an experimental study of quartz flake fragmentation. We evaluate the method called fracture analysis that has been developed and used explicitly for the study of quartz assemblages. The method assumes high predictability of quartz flake fragmentation, but our experiments show that there is significant variation in fragmentation that fracture analysis does not take into account. Our results indicate that this variation is partly explained by indenter hardness, the relative thickness of the detached flake, as well as individual knapper-related factors. These results undermine the applicability of quartz fracture analysis in its current form. In addition, we discuss the effects of flake fragmentation on the technological organisation of prehistoric quartz users and suggest that it has affected reduction strategies as well as blank and tool dimensions. We also suggest that there should be mobility-related differences in archaeological assemblages in terms of the quality of the quartz raw material and that the curation of quartz should be low in relation to better quality raw materials used parallel with it.     

A geometric morphometric relationship predicts stone flake shape and size variability

The archaeological record represents a window onto the complex relationship between stone artefact variance and hominin behaviour. Differences in the shapes and sizes of stone flakes—the most abundant remains of past behaviours for much of human evolutionary history—may be underpinned by variation in a range of different environmental and behavioural factors. Controlled flake production experiments have drawn inferences between flake platform preparation behaviours, which have thus far been approximated by linear measurements, and different aspects of overall stone flake variability (Dibble and Rezek J Archaeol Sci 36:1945–1954, 2009; Lin et al. Am Antiq 724–745, 2013; Magnani et al. J Archaeol Sci 46:37–49, 2014; Rezek et al. J Archaeol Sci 38:1346–1359, 2011). However, when the results are applied to archaeological assemblages, there remains a substantial amount of unexplained variability. It is unclear whether this disparity between explanatory models and archaeological data is a result of measurement error on certain key variables, whether traditional analyses are somehow a general limiting factor, or whether there are additional flake shape and size drivers that remain unaccounted for. To try and circumvent these issues, here, we describe a shape analysis approach to assessing stone flake variability including a newly developed three-dimensional geometric morphometric method (‘3DGM’). We use 3DGM to demonstrate that a relationship between platform and flake body governs flake shape and size variability. Contingently, we show that by using this 3DGM approach, we can use flake platform attributes to both (1) make fairly accurate stone flake size predictions and (2) make relatively detailed predictions of stone flake shape. Whether conscious or instinctive, an understanding of this geometric relationship would have been critical to past knappers effectively controlling the production of desired stone flakes. However, despite being able to holistically and accurately incorporate three-dimensional flake variance into our analyses, the behavioural drivers of this variance remain elusive.     

The technology of Stone Age colonization: an empirical,regional-scale examination of Clovis unifacial stone tool reduction,allometry, and edge angle from the North American Lower Great Lakes region

There is now broad consensus that the appearance of Clovis in Northeastern North America (Great Lakes, New England) represents a colonization pulse into recently deglaciated landscapes. Due to the increased resource uncertainty that comes with colonizing unfamiliar landscapes, it was hypothesized that the majority tool component of Clovis assemblages, unifacial stone tools, should have been knapped on tool blanks possessing the design properties of longevity and functional flexibility to facilitate exploration mobility and guard against the absence of toolstone sources in the new landscape. These properties are optimized by large, flat flakes, possessing large surface area relative to flake thickness. Since discarded and, at times, exhausted unifacial stone tools do not preserve the original dimensions of the blank upon which they were created – necessary items for a true test of blank morphology selection – this study presents a set of predictions for inferring whether Clovis unifacial stone tool blanks were selected for the properties of longevity and functional flexibility based on evidence that Clovis people actually capitalized on those properties. Due to the nature of Clovis unifacial stone tools, tool size was of necessity used as a proxy for tool reduction, on the grounds that smaller tools are more likely to have been resharpened than larger tools, at least in the case of unifacial flake tools. The results showed that less resharpened tools possessed flatter, less spherical shapes than the more resharpened tools, which possessed more globular, spherical shapes, suggesting Clovis foragers exploited the retouch potential afforded by the larger, flatter blanks. Edge angles showed no relationship with tool reduction, suggesting that Clovis foragers exploited the functional flexibility afforded by flatter blanks by adjusting the edge angle to be either higher or lower as needed. These results are consistent with the notion that human colonizers, who did not know the abundance or location of stone outcrops prior to settling an unfamiliar territory, not only “geared up” before leaving a stone source, but geared up as efficiently as possible by carefully selecting the blanks they chose to carry. Broader implications for such careful unifacial stone tool blank selection are discussed.     

骨质修理器——石器修理的新视角

本文介绍在欧洲旧石器时代遗址中发现较多的用于修理石器的动物骨头和牙齿。这类工具被称为骨质修理器,为解读石器修理技术和人类对动物资源的利用提供了重要线索。文章通过实验揭示了骨质修理器的操作过程、效能及其痕迹特征,有助于分析修理器的技术和行为内涵。从技术操作和原材料的来源与供给来看,使用骨头或牙齿修理石器是很有效的方法且成本低。最后从考古材料来看,骨质修理器在欧洲旧石器时代中期和晚期常见,而在东亚尚未发现。这种分布特点可能反映了人类对原材料选择利用和文化传统的差异;另一方面随着我们对骨质修理器的关注和认识,随着动物遗存与石制品综合系统研究的开展,这种工具有可能在更多地区被发现,为研究旧石器时代的技术和人类行为提供更丰富的材料与视角。     

DNA from ancient stone tools and bones excavated at Bugas-Holding,Wyoming

DNA residues may preserve on ancient stone tools used to process animals. We studied 24 stone tools recovered from the Bugas-Holding site in northwestern Wyoming. Nine tools that yielded DNA included five bifaces, two side scrapers, one end scraper, and one utilized flake. The excavators did not handle three of these tools with bare hands, and they were sealed in separate plastic bags to minimize contact with modern DNA. Five sediment samples did not yield mammalian DNA. One tool contained DNA from three species, and these templates competed during polymerase chain reaction (PCR) amplification. DNA identifications suggested a butchery pattern indicative of a human population under resource stress or a broader range of industrial activities at Bugas-Holding. We describe several improvements in DNA residue analysis, including a more effective DNA recovery protocol, methods to measure sensitivity and inhibition of PCR in each sample, and strategies to surmount competition between templates during PCR.     

Kuhn's Geometric Index of Unifacial Stone Tool Reduction (GIUR): does it measure missing flake mass?

Kuhn's GIUR is a set of measurements taken on a resharpened stone flake's edge. Its purpose is to estimate the amount of stone removed before the exhausted tool was abandoned. An experimental test of Kuhn's Index led Hiscock and Clarkson to suggest that it is an excellent estimator of flake mass loss. Our own tests, using different experimental procedures, reached much less optimistic conclusions. Here, we apply their own measurement procedures, and successfully duplicate their results. It does not follow, however, that our now-consistently high correlations have a causal connection. As GIUR values increase, they are less able to estimate the actual loss of flake mass. It appears, therefore, that incremental loss of flake mass need not be the sole driver of the GIUR value. If the correlation is an inevitable byproduct of the experiment's design, as it now appears, then analyses based on this high correlation will be misleading. The GIUR remains, however, and excellent gauge of flake edge exhaustion.     

Edge Angle as a Variably Influential Factor in Flake Cutting Efficiency: An Experimental Investigation of Its Relationship with Tool Size and Loading

Simple flake cutting tools were utilized across broad chronological and geographical ranges during prehistory. Fundamental to their functional utility is the presence of a relatively acute working edge. The acuteness of this ‘edge angle’ is widely hypothesized to be a primary determinant of cutting efficiency and, subsequently, of potential consequence to prehistoric peoples. However, the influence of the cutting edge angle in flake tools on the ability (efficiency) of tool users to cut through objects has not been empirically investigated under explicitly stated experimental conditions. Moreover, no consideration has been given to whether this relationship is dependent upon the size of the tool. Here, the influence that edge angle exerts on human stone tool users is examined experimentally in terms of efficiency during a cutting task, while also considering the relationship between edge angle, loading (i.e., the force applied) and overall flake size. The results demonstrate that there is a highly significant relationship between more acute working edges and increased cutting efficiency in the smallest flake tools tested. Above a certain flake‐size threshold, however, the working edge angle has no influence on cutting efficiency because larger flakes appear to facilitate the application of greater working loads by tool users. These results have important implications for potential flake selection criteria by prehistoric peoples, especially in relation to utility, function and the changing effects of edge angle through a sequence of retouch.     

A Twenty-First Century Archaeology of Stone Artifacts

Archaeologists today, as in the past, continue to divide their stone artifact assemblages into categories and to give privilege to certain of these categories over others. Retouched tools and particular core forms, for instance, are thought to contain more information than the unretouched flakes and flake fragments. This reflects the assumption that information to be gained from stone artifacts is present within the artifact itself. This study evaluates a continued interest in the final form of stone artifacts by first considering ethnographic accounts of stone artifact manufacture and use in Australia and then by utilizing the patterns observed in these accounts to investigate assemblage patterning within an Australian archaeological case study. Reading the ethnographic accounts provides no indication that Aboriginal people valued more or less complex artifacts, in uniform ways, in every situation. In fact, the opposite is true. Stone artifacts were always valued in some sense but which ones, and in which ways, depended on the situations the people who needed the artifacts found themselves in. Aboriginal people were quite capable of making and using expedient and informal artifacts in complex ways. The significance of these observations is considered for stone artifact studies in general and in relation to a case study from western New South Wales, Australia.     

An Index of Invasiveness for the Measurement of Unifacial and Bifacial Retouch: A Theoretical,Experimental and Archaeological Verification

Archaeologists are increasingly in need of quantitative measures of stone artefact retouch. Existing techniques fail to provide a generic measure of retouching for all chipped stone artefacts. A fast and reliable index is proposed which measures retouch in terms of the invasiveness of flake scars on the surfaces of complete stone artefacts. Unlike other measures, the index of invasiveness is well suited to the analysis of bifacially worked artefacts such as bifacial points and bifaces. Experimental tests demonstrate a strong correlation between the index and measures of reduction based on diminishing flake weight and numbers of retouch blows. Inter-observer reliability is also demonstrated through the use of a blind test. Limitations of the method are discussed, although potential techniques for surmounting problems are identified. An archaeological application of the index demonstrates the utility of the method in the context of regional assemblage variability in northern Australia.     

Technology based evolution? A biometric test of the effects of handsize versus tool form on efficiency in an experimental cutting task

The use of stone cutting tools opened a novel adaptive niche for hominins. Hence, it has been hypothesised that biomechanical adaptations evolved to maximise efficiency when using such tools. Here, we test experimentally whether biometric variation influences the efficiency of simple cutting tools (n = 60 participants). Grip strength and handsize were measured in each participant. 30 participants used flint flakes, while the other 30 used small (unhafted) steel blades. Variations in basic parameters of tool form (length, width, thickness, cutting edge length) were recorded for the 30 flint flakes. It was ensured that mean handsize and strength in each participant group were not significantly different to investigate the effect of tool variation. The experimental task required cutting through a 10 mm-diameter hessian rope. Cutting efficiency was measured using both ‘Number of cutting strokes required’ and ‘Total time taken’. Results show that both efficiency measures were significantly correlated with handsize using all 60 participants. However, no significant differences were found between the flake and blade groups in terms of mean efficiency. Nor was any significant relationship found between tool form parameters and efficiency in the flint flake group. We stress that our results do not imply that tool form has no impact on tool efficiency, but rather that – all other things being equal – biometric variation has a statistically significant influence on efficiency variation when using simple cutting tools. These results demonstrate that biomechanical parameters related directly to efficiency of use, may plausibly have been subject to selection in the earliest stone tool-using hominins.     

Factors affecting Early Stone Age cut mark cross-sectional size: implications from actualistic butchery trials

Early Stone Age cut marks are byproducts of hominins' tool-assisted animal carcass consumption and provide a potential avenue of inference into the paleoecology of hominin carnivory. If diagnostic cut mark characteristics can be linked to flake and core tool use or the completion of distinct butchery actions, it may be possible to infer ancient tool preferences, reconstruct the consumption of specific muscular tissues, and illuminate landscape-scale stone resource use. Recently, diagnostic morphological criteria including cut mark width and depth have been used to identify marks made by different classes of experimental and archaeological stone tools (Bello, S.M., Parfitt, S.A., Stringer, C., 2009. Quantitative micromorphological analyses of cut marks produced by ancient and modern handaxes. Journal of Archaeological Science 36: 1869–1880; de Juana, S., Galan, A.B., Dominguez-Rodrigo, M., 2010. Taphonomic identification of cut marks made with lithic handaxes: an experimental study. Journal of Archaeological Science 37: 1841–1850; Dominguez-Rodrigo, M., de Juana, S., Galan, A. B., Rodriguez, M., 2009. A new protocol to differentiate trampling marks from butchery cut marks. Journal of Archaeological Science 36: 2643–2654). The work presented here adds to this experimental butchery database by using measurements of cut mark cross-section taken from bone surface molds to investigate how stone tool characteristics including flake versus core tool type, edge angle, and tool weight, influence cut mark width and depth, ultimately testing whether cut mark size is a useful indicator of tool identity. Additionally, these experiments investigate the influence of contextual factors, including butchery action, carcass size, and bone density on cut mark size. An experienced butcher used replicated Oldowan flakes and bifacial core tools in experimental trials that isolated skinning, bulk and scrap muscle defleshing, and element disarticulation cut marks on goat and cow skeletons. This sample explores cut mark traces generated under realistic butchery scenarios and suggests the following results: 1) Core and flake tools were equally efficient at completing all butchery tasks in size 1 and 3 bovid carcasses. 2) Samples of cut mark width and depth produced by core and flake tools were similar and cut marks could not be accurately classified to a known tool type. 3) Skinning and disarticulation activities produced significantly wider and deeper marks than defleshing activities. 4) Cut marks on cows tended to be wider and deeper than those on goats. 5) Cut mark width is negatively correlated with bone density when carcass size and bone portion are taken into consideration. These results suggest that a general quantitative model for inferring tool type or edge characteristics from archaeological cut mark size is not warranted.     

乾陵东一翁仲裂隙调查及稳定性分析

乾陵东一翁仲病害众多,但裂隙是危及其安全的首要因素。通过现场调查确定了东一翁仲裂隙分布特征并对其稳定性进行了分析。结果表明:东一翁仲现存5条影响其稳定性的裂隙,其中3条贯通,2条局部贯通。裂隙将石刻分割为5个块体,中间块体上大下小且重心前偏,导致石刻整体前倾,为石刻失稳提供了动力来源,脚后跟块体是石刻稳定的关键块体。石刻目前处于欠稳定状态,当遇到关键块体上部破碎、钢箍断裂失效、地震荷载等任一情况时,石刻将处于失稳状态,有整体倒塌的危险。研究结果可为东一翁仲的保护工作提供科学依据。     

就石片台面研究问题答李炎贤

石片包括了各种类型台面的石片,石片台面的分类可以视为石片分类的一种。旧石器时代考古术语需要斟酌和规范。科学研究必须实事求是。     

山西吉县柿子滩遗址第九地点发掘简报

该地点出土的石器以锤击法打片、压剥法第二步加工和小型石片石器为主,刮削器、尖状器、砍砸器石器组合和细石叶压剥技术等代表了北方细石器文化的特征。出土的石磨盘、石磨棒、颜料块和研磨石等为研究旧石器时代晚期文化向新石器时代早期文化的过渡和华北地区原始农业的起源提供了资料。     

Bone surface modifications in zooarchaeology

Cutmarks made by stone tools, conchoidal flake scars from hammerstone percussion, carnivore tooth marks, striations from sedimentary abrasion, and other surface modifications on bones from archaeological sites constitute a crucial body of evidence for investigating the role of human behaviors and of nonhuman taphonomic processes in site formation. This paper describes the various kinds of bone surface modifications produced by humans and by nonhuman processes and assesses the current status of bone surface modification studies with regard to such issues as the need for greater analytical standardization, the selection of instruments for examining bone specimens, tactics for identifying the origins of marks on bones, and strategies for inferring human behaviors.     

Plastic Hinge Length for Lightly Reinforced Rectangular Concrete Walls

This research investigates the plastic hinge length in lightly reinforced rectangular walls typically found in regions of low-to-moderate seismicity. Poor performance has been exhibited by lightly reinforced concrete walls in past earthquake events. A series of finite element analyses have been carried out which demonstrate that if the longitudinal reinforcement ratio in the wall is below a certain threshold value, there will not be sufficient reinforcement to cause secondary cracking, and instead fracture of the longitudinal reinforcement at a single crack could occur. A plastic hinge length equation has been derived based on the results from the numerical simulations.     

Approaching the Hatch Jasper Quarry From a Technological Perspective: A Study of Prehistoric Stone Tool Production in Central Pennsylvania

Abstract

Mitigation of the Hatch jasper quarry, a “prospect site” in Central Pennsylvania, has enabled the reconstruction of a local system of stone tool acquisition and production. Artifacts from the quarry and the nearby Houserville habitation complex were analyzed using an attribute-based stage typology. This technological approach permitted the separation of geofacts from artifacts, and revealed evidence suggesting that Houserville knappers obtained tool stone from the quarry. Attention was also given to the study of how systematic heat treatment was used to enhance the flaking characteristics of the Hatch quarry jasper. This research highlights the benefits that a technological analysis of flake artifacts, in addition to finished tools, can provide for understanding stone tool production at quarry localities.     

Estimating original flake mass from 3D scans of platform area

This study confirms the increased capacity to predict flake mass that arises from more accurately measuring surface area in three dimensions using a digital scanner. We also reveal the existence of significantly different relationships between platform area and flake mass for flakes with different platform types and ventral and dorsal morphologies. These different relationships between platform surface area and mass have not been previously identified, and reveal the complexity of platform/mass relationships. Using multivariate regression of 3D platform surface area and external platform angle we improve the accuracy of predictions of original flake mass. We propose a method for studying reduction intensity on retouched flakes, based on comparing predictions of the initial mass of the flake with measurements of the mass following retouching to estimate the amount of mass removed through retouching. We name this approach the Initial-/Terminal-Mass Comparison, or ITMC. Our experiments demonstrate that the capacity of the 3D platform scans to predict flake mass, and by implication the capacity of the ITMC to estimate mass loss, rivals or exceeds the capacity demonstrated for existing reduction measures.