Experimentation in the Formation of Edge Damage: A New Approach to Lithic Analysis

Abstract

The paper describes a series of experiments recently carried out to test the formation of edge-damage on flaked stone tools which results from their being used in various tasks. Variables that were systematically tested include action, worked material, angle of the edge, and grip. The main criterion in distinguishing different patterns of damage was microflaking rather than abrasion in the form of striations and polish.

The results of these experiments may be applied to the identification of patterns of damage to the edges of prehistoric stone tools. The information gained from such microwear analysis may be used not only to provide details on the activities and settlement organization of prehistoric societies, but also to provide an important new dimension to lithic analysis in general. In lithic analysis, the main criteria of change have been the macromorphological features of the tools. It is our contention, however, that the additional information on the function of the tools, which is provided by microwear analysis, can contribute to the greater understanding of the processes of change in lithic assemblages and culture change as a whole.

The experimental program was designed to test the formation of edge-damage on implements manufactured in European chalk flint. It was to aid in the identification of wear patterns on lithic assemblages from the neolithic period in Central and Eastern Europe, a project in which the authors were involved. Its relevance, however, includes directly those assemblages of the post-Pleistocene period in temperate and Mediterranean Europe. The results of the experiments may also be useful, it is hoped, for lithic analysis in general, both in the Old and New World.     

Pervasiveness of phytoliths in prehistoric southwestern diet and implications for regional and temporal trends for dental microwear

Our previous analysis of phytolith content of coprolites showed that calcium oxalate phytoliths from desert food plants caused dental microwear among prehistoric Texas hunter-gatherers. We demonstrated that phytoliths from desert succulents were ubiquitous and abundant in hunter-gatherer coprolites. We found that calcium oxalate phytoliths were harder than human dental enamel. We concluded that phytoliths from desert succulent plants caused dental microwear and hypothesized that such dental microwear would be common in other desert hunter-gatherer and horticultural peoples. Presented here are further analyses of phytoliths from coprolites. Two additional hunter-gatherer sites and three Ancestral Pueblo (Anasazi) horticultural sites are included in this study. Calcium oxalate phytoliths are ubiquitous in coprolites from hunter-gatherer sites in the Mojave Desert and the Colorado Plateau. For the three Ancestral Pueblo sites, calcium oxalate phytoliths from desert succulents (agave family and cactus family) are the most common types of phytoliths encountered. However, silica phytoliths are also present in Ancestral Pueblo coprolites. The data demonstrate that phytoliths from non-cultivated desert plants were a source of dental microwear for the pre-maize Archaic hunter-gatherer bands and maize-reliant Ancestral Pueblo villages.     

Occlusal microwear texture analysis and the diets of historical/prehistoric hunter‐gatherers

With the exception of few studies, occlusal microwear of pre‐agricultural modern humans has not been documented. In this study, microwear fabrics of samples from seven historic/prehistoric hunter‐gatherer populations with known and diverse dietary habits, representing mostly meat‐eaters from different environments, arctic/tundra (Tigara from Point Hope), cold‐steppe (Fuegians) and Mediterranean (Chumash), and mixed‐diet hunter‐gatherers from tropical climates (Andamanese and Khoe‐San from Matjes River, Riet River, and Oakhurst Shelter), were analysed to better understand how dietary differences affect microwear in these groups and to establish a reasonable comparative database for interpreting fossil hominins microwear. Significant microwear differences, related to diet and food preparation techniques, between the meat‐eaters and mixed‐diet hunter‐gatherers were detected. Finer scale differences within each of these dietary categories were also observed. Ethnographic accounts indicate that the Tigara and Andamanese ingested hard particles attached to their food as a result of their food preparation techniques; their microwear fabrics also reflect highly abrasive diets. On the other hand, as expected, the microwear signatures of the Chumash and Fuegians indicate a diet low in abrasives, reflecting their almost exclusive reliance on marine meat for subsistence and the low amounts of extraneous particles attached to this meat. The mixed‐diet Khoe‐San occupy an intermediate position between the Tigara and Andamanese on the one hand, and the Chumash and Fuegians on the other, with regard to the level of abrasives ingested. The Khoe‐San ate large amounts of hard plants, most likely responsible for abrading their enamel surface. Copyright © 2008 John Wiley & Sons, Ltd.     

Testing Area‐Scale Fractal Complexity (Asfc) and Laser Scanning Confocal Microscopy (LSCM) to Document and Discriminate Microwear on Experimental Quartzite Scrapers

Few microwear studies have been conducted on tools made from quartzite. Most rely on visual observation of microwear features using optical light microscopes and scanning electron microscopes. Quantification of microwear on quartzite tools is extremely rare, even though numerous methods to mathematically document surface roughness have been applied to other silicate tools. In this paper, laser scanning confocal microscopy (LSCM) was used to document surface roughness on four experimental scrapers made from two different subtypes of Mistassini quartzite that were used on either fresh or dry deer hide. Surface roughness data were analysed using area‐scale fractal complexity (Asfc). The results of this test case indicate that Asfc can effectively discriminate between the unused and used regions on the quartzite tools based on surface roughness, and that it can also discriminate between surface roughness produced by working dry versus fresh hides. Differences in the subtypes of Mistassini quartzite did affect surface roughness, but not significantly enough to prevent discrimination of the dry and fresh hide‐working tools. Although the use of the Asfc parameter for lithic microwear analysis requires further testing, these first results suggest it could be a reliable technique to mathematically document and discriminate wear patterns on archaeological quartzite tools.     

The elemental chemistry of lithic microwear: an experiment

This paper examines the ability of elemental analysis to distinguish microwear traces on stone tools. Our research hypothesised that cleaning procedures of experimental specimens may have heavily influenced previous studies in this area. Experimental flakes are used and cleaned by two alternative methods before laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is applied to study use-wear chemistry. The results show that elementally recognisable traces remain on stone surfaces even with severe cleaning. Also studied were archaeological sickle blades from two sites in Northern England. The results were counter-intuitive demonstrating that experimentally validated models potentially require extensive modification and clarification before being applied to archaeological material. This research identifies methodological problems and errors concerning cleaning within previous experimental studies and highlights new directions for this quantitative analytic approach in microwear analysis.     

Scanning electron microscopy of dry hide working tools: The role of abrasives and humidity in microwear polish formation

This paper presents the results of the scanning electron microscopy of a series of experimental tools designed to investigate the role of abrasive agents and humidity in microwear polish formation. The tools—35 end scrapers—were divided into four groups and used to work dry hide. It was found that both humidity and abrasive agents are two basic variables in the development of the microwear polish.     

Salt mining tools and techniques from Duzdaği (Nakhchivan,Azerbaijan) in the 5th to 3rd millennium B.C.

The emergence of mining reflects profound changes in the organization of late prehistoric societies. In terms of lithic and ore mining, salt is a highly strategic mineral resource which was exploited for its dietary and healing properties. The exceptional prehistoric salt mine of Duzda?i (Nakhchivan, Azerbaijan) is located in a high salt-bearing region centered on the Aras River in the Lesser Caucasus. Field survey, spatial recording of archaeological materials and use-wear analysis of macrolithic tools have allowed us to outline the mining operations and techniques there from the Chalcolithic period onwards. We have identified workshops for the manufacture and repair of tools, as well as salt extraction and processing areas.     

AN INTERIM REPORT OF THE STAR CARR MICROWEAR STUDY

Summary. This paper presents some preliminary observations based on the microwear analysis of 173 artefacts from the mesolithic site of Star Carr, near Scarborough, Yorkshire. One hundred discrete and utilized edges were identified by the presence of various microwear traces on 79 of the artefacts belonging to the following general types: scrapers, edge-damaged or marginally retouched blades and flakes, bilaterally backed blades (awls), burins, backed blades, axe resharpening flakes, denticulated or truncated blades and flakes, microliths, and cores. The microwear traces identified on the tools indicates that they were used in a variety of ways in the processing of hide, bone, wood, antler and meat. A comparison of wear-traces and tool shape has shown that there are morphological differences between scrapers used on hide and those used on bone, and also, that edge-damaged or marginally retouched blades were selected for use on the basis of their cross-sectional configuration.     

Occlusal molar microwear and the diets of the Ipiutak and Tigara populations (Point Hope) with comparisons to the Aleut and Arikara

Archaeological excavations at Point Hope, Alaska uncovered skeletal remains of two populations: the Ipiutak (100 B.C.–500 A.D.) and Tigara (1200–1700 A.D.). Archaeological evidence indicates that, although both groups relied on animal (largely marine) resources for their subsistence, the Ipiutak were mainly caribou hunters, whereas the Tigara were primarily whale hunters. To date, no study has attempted to ascertain whether the inferred dietary differences of these two groups could be substantiated using a more direct technique, e.g. microwear or stable isotope analysis. In this study, the occlusal molar microwear fabrics of the Ipiutak and Tigara were analyzed. Comparative data for two other modern human groups, the Aleut and Arikara, were also examined. Significant differences in microwear signatures were detected among the groups considered. The results of this study show that the Tigara have significantly more microwear features, more pits and narrower scratches compared to the Ipiutak. These results are concordant with interpretations that the two Point Hope populations had significantly different dietary habits. Differences in microwear signatures between the Aleut and the two Point Hope populations were also detected. Compared to the two Point Hope populations, the Aleut has significantly fewer features and wider scratches. The Aleut microwear signature further differs from that of the Tigara in having significantly lower pitting incidence. The microwear pattern of the Arikara, who had a mixed diet, differed from that of the mainly meat-eating Aleut and Point Hope peoples in that the Arikara has significantly fewer features, lower pitting incidence and narrower scratches.     

An investigation of the fractal properties of flint microwear images

This paper reports on an investigation into the fractal dimensions of flint microwear images which has been carried out in an attempt to resolve the existing controversy over the possibility of identifying microwear types from visual inspection of high magnification images, and describes a new method for flint microwear image analysis based on fractal geometry. Fractal dimensions of surface images, which are known to relate well to human visual perception of roughness, have been computed for various types of microwear. No significant correlations have been found between the fractal properties of the digital flint images and the contacted materials.     

Dental microwear study of pigs from the classical site of Sagalassos (SW Turkey) as an aid for the reconstruction of husbandry practices in ancient times

Abstract

Microwear analysis of pig teeth from the classical site of Sagalassos (SW Turkey) is undertaken to obtain insight into pig management strategies in this region from the 1st to 7th centuries AD. Earlier research on modern pigs revealed significant differences in microwear patterns between stall-fed and free-ranging, rooting individuals. A comparison of the microwear data of the Sagalassos pig with those from archaeological and modern pigs with a known or presumed type of management shows that the microwear of the Sagalassos pigs is very different. It is suggested that the Sagalassos pigs had a very soft, non-abrasive diet, that in the first instance cannot be attributed to either management type. Therefore, the nature of the substrate on which the animals were foraging and its impact on microwear are considered and the microwear data are compared with the results of previous archaeozoological research carried out at the site. Further, diachronic changes in microwear patterns are investigated.     

Recent developments in the analysis of lithic artifacts

A review of recent research on lithic technology and functional analysis is presented. Our perception of the state of the art is based on a review of the literature published during the past three years and on the topics that were covered at conferences and workshops on lithic analysis. While the goals have essentially remained the same since the turn of the century, concerns with chronology and the classification of lithic artifacts have given way to studies that treat stone implements as products of a dynamic system of human behavior. In order to understand stone artifacts and the people that made and used them, archaeologists must understand theprocesses involved in the acquisition, production, exchange, and consumption of lithic artifacts. In the past ten years, experimental studies involving the manufacturing and use of stone tools have been integrated with studies of refitted or conjoined lithic artifacts and microwear analysis. The result is a much more dynamic view of the variability in assemblages of lithic artifacts. In this review, we focus on replication and technological analysis of chipped stone artifacts and microwear analysis, and consider the implications of this research.     

UNRETOUCHED BLADES IN THE LATE MESOLITHIC OF SOUTH SCANDINAVIA. A FUNCTIONAL STUDY

Summary. While most microwear analyses of flint artefacts have involved formal retouched tools, this paper concentrates on unretouched blades from 4 South Scandinavian Mesolithic sites, seeking to establish how frequently and on what materials such pieces were used and whether they were selected for identifiable morphological reasons. The results are based on a study of 496 specimens, from various archaeological contexts. The materials processed ranged from soft to medium hard and most blades were used once only, as disposable tools. Their role relates more to 'manufacturing'than 'subsistence'activities. Blades seem to have been selected mainly according to their edge angles, with specific tasks in mind (a situation for which ethnographic parallels can be quoted), and they were evidently deliberately struck with a view to use rather than being chosen from random débitage. Various aspects of these conclusions are discussed.     

Do silica phytoliths really wear mammalian teeth?

There is considerable literature suggesting that silica (opal) phytoliths cause dental enamel microwear in mammals. Much of this literature cites a single study from 1959 as evidence that silica phytoliths are harder than mammalian tooth enamel and so have the potential to cause dental microwear. No other studies using similar methodology have actually confirmed whether phytoliths are harder than dental enamel.     

Practical quantitative lithic use-wear analysis using multiple classifiers

Although use-wear analysis of prehistoric stone tools using conventional microscopy has proven useful to archaeologists interested in tool function, critics have questioned the reliability and repeatability of the method. The research presented here shows it is possible to quantitatively discriminate between various contact materials (e.g., wood, antler) using laser scanning confocal microscopy in conjunction with conventional edge damage data. Experiments with replica and prehistoric tools suggest the quantitative method presented here provides valid functional inferences and is flexible enough to accommodate other relevant sources of data on tool function.     

Reconstruction of Caprine Management and Landscape Use Through Dental Microwear Analysis: The Case of the Iron Age Site of El Turó de la Font de la Canya (Barcelona,Spain)

This paper presents the results of a pilot study using dental microwear analysis on 23 sheep and goat teeth dated to the 6th century BC from the Iron Age site of El Turó Font de la Canya (Barcelona, Spain). This study aimed to reconstruct livestock management practices and landscape use. The dental microwear pattern indicates that sheep and goats could have been grazing in the same area where vegetation was composed of shrubs, bushes and non-graminaceous plants on an eroded landscape, although additional supplies of fodder cannot be excluded. This scenario is compatible with the archaeological and palaeoenvironmental data which suggest a possibly increased territoriality, land degradation and an increase of woodland clearance during Iron Age in the North-east of the Iberian Peninsula. Furthermore, we applied two recent microwear approaches which provide more information about mortality events and the possibility of distinguishing between an intensive and extensive management. This paper demonstrates how this method can be used to better understand animal husbandry practices and landscape use in Late Prehistory.     

De-mystifying Pottery Production in the Maya Lowlands: Detection of Traces of Use-Wear on Pottery Sherds through Microscopic Analysis and Experimental Replication

During the Late Classic period at the site of K'axob in Belize, Central America, inhabitants recycled ceramic fragments as tools for the making of pottery. Considering pottery as a tool is by no means an easy task and requires, for its study, significant methodological innovation. The K'axob pottery tools demanded a comprehensive study to determine their use and function within this widespread economic activity. Research presented here incorporated fabrication of replicas of archaeological pottery tools and their experimental use for the making of ceramic vessels. Combined microscopic analysis of archaeological and fabricated tools defined and reproduced wear traces from use activities. Therefore, this investigation entails a methodological innovation to archaeology, yielding a broader perspective into prehistoric technologies.     

Thermally Altered Novaculite and Stone Tool Manufacturing Techniques

Abstract

This paper describes a study of the physical origins of improved flaking properties, called flakeability, for novaculite, a material exploited for stone tool manufacture by the peoples of prehistoric Arkansas, Missouri, Texas, and Louisiana. Experimentation in thermal pretreatment and ways to detect and discriminate the results of this pretreatment were carried out. The criteria derived for distinguishing this alteration in the novaculite are easily determined by a straightforward analysis that can be done in almost any laboratory.

The results of this experimentation have direct implications for the study and identification of thermal pretreatment in this and other stone materials. From the correlations between the physical alteration of such source materials and the implication for manufacturing techniques, the archeologist can more validly infer relationships between prehistoric lithic technology and the knappers who developed highly diversified and specialized techniques. Such experiments combined with wear analysis, material source determination, and other lithic studies will allow the archeologist to delineate manufacturing and exploitative patterns and examine their relationship to all forms of cultural and environmental variables.     

Integrating dental microwear and isotopic analyses to understand dietary change in east-central Mississippi

Stable isotope and dental microwear analyses are integrated to observe changes in plant food diet in east-central Mississippi. Dental specimens are compared from seven sites in Mississippi and one in Alabama ranging in time from the Archaic to the Protohistoric periods. Microwear analysis of phase II dental facets is performed and pit percentages, scratch length and width, and pit length and width are recorded. Analysis of variance statistical tests were performed between temporally contiguous sites. The results indicate that the size and frequency of microwear features decrease through time until the Protohistoric period where pit feature size and frequencies increase significantly. These results are then compared to stable isotope analysis to test whether the methods yield congruent results and to assess additional dietary changes, specifically the increased importance of nut foods. Carbon isotope analysis indicates differences in dietary maize use between the Mississippian and Protohistoric samples and dental microwear analysis show a significant increase in pit percentages and pit size, microwear features generally associated with hard food mastication. One important question addressed is whether there was a return in the Protohistoric period to naturally available resources, specifically hard foods such as nuts, a pattern observed at sites in Alabama and Arkansas. The use of secondary burials in the later Protohistoric period is examined as a possible cause for this microwear pattern. The study demonstrates the importance of integrating different methods when assessing dietary change, especially when ethnobotanical information is not available.     

A note on the use of temporal frequency distributions in studies of prehistoric demography

Temporal frequency distributions of archaeological sites and radiocarbon dates are commonly used as proxies for prehistoric population levels based on the assumption that more people create a stronger archaeological signal. While this assumption is certainly correct, we question whether relative frequencies of sites or dates observed from prehistoric contexts are necessarily linked to human demography. In this paper, we demonstrate that the typical positive curvilinear frequency distributions observed in archaeological contexts also regularly occur in paleontological and geological contexts and are thus likely caused by the operation of time-dependent destructive processes, what we call “taphonomic bias.” Using a simple model, which assumes a constant rate of site loss over time, we show how taphonomic bias can produce positive curvilinear frequency distributions through time even in cases of population stasis, decline, and fluctuation. We conclude that caution must be used when attempting to infer demographic trends from frequency distributions alone.