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.     

Microwear analysis of experimental flint tools: a test case

Recent attempts to infer the functions of prehistoric stone tools have centred on the study of microscopic traces of wear on the surfaces of these tools. One method of “microwear analysis” involving high magnification and an incident light microscope is tested in this paper. Modern flint tools made and used in ways thought relevant to prehistory were produced by a lithic technologist and after cleaning given to the microwear specialist who attempted to infer their use. A high degree of agreement between inferred and actual uses was achieved and this encouraging result has important implications for the study of microwear on prehistoric tools where no such independent check is available.     

Use of stone hammer tools and anvils by bearded capuchin monkeys over time and space: construction of an archeological record of tool use

Wild bearded capuchins (Sapajus libidinosus) in the cerrado (seasonally dry savannah-like region) of Brazil routinely crack open several species of palm nuts and other hard encased fruits and seeds on level surfaces (anvils) using stones as hammers. At our field site, their nut cracking activity leaves enduring diagnostic physical remains: distinctive shallow depressions (pits) on the surface of the anvil, and cracked shells and stone hammer(s) on or next to the anvil. A monthly survey of the physical remains of percussive tool use at 58 anvils in our study site over a 36-month period revealed repeated use, seasonal consistency, temporal variation, landscape-scale patterning, appearance of new hammers and transport of existing hammers to new anvil sites. Artefactual evidence of the temporal and spatial pattern of tool use collected in the survey is in correspondence with concurrent direct observation of monkeys using and transporting tools at this site. Shell fragments endure for years above ground, suggesting that they may also endure in the strata around anvil sites. The bearded capuchins provide an opportunity to study the construction of percussive tool sites suitable for archeological investigation concurrently with the behavior responsible for the construction of these sites. We suggest several lines of inquiry into tool sites created by capuchin monkeys that may be useful to interpret the archeological evidence of percussive tool use in early humans. Archeologists should be aware that transported stone materials and artificial durable landscape features may be the result of activity by non-human animals.     

Microwear study of quartzite artefacts: preliminary results from the Middle Pleistocene site of Payre (South-eastern France)

Preliminary functional results obtained from the quartzite assemblage of the Early Middle Palaeolithic site of Payre (South-eastern France) are presented. In an area rich in flint, hominins at Payre also collected quartzite in their local environment, specifically along the Rhône River banks. Although the Payre lithic assemblage is largely composed of flint, quartzite was introduced in the site mainly as large cutting tools knapped outside. This fact pointed out an apparently highly differential treatment of the raw material types available in the region. A major concern is to understand the reason why. Is there any functional reason for the introduction of those artefacts, perhaps to perform specific activities related to the toughness of quartzite? Or is there any functional differentiation among the various raw materials? Use-wear analysis is a useful tool for better understanding human technological choices and strategies of lithic raw material management. Before attempting to extensively apply use-wear analysis on the quartzite assemblage, we analysed a limited sample to evaluate the general surface preservation. A specific experimental programme with the same local quartzite was carried out in order to provide a reliable comparative reference for interpreting use-wear evidence on archaeological implements. Methodological difficulties related to use-wear analysis applied to quartzite artefacts are also discussed. Both Optical light microscopy (OLM) and Scanning Electron Microscopy (SEM) were employed in this study; however, interpretations were elaborated considering principally SEM micro-graphs.The analysis of the archaeological material showed a good state of preservation of the surfaces with a low incidence of post-depositional alterations. The documented use-wear allowed us to identify the active edges, the kinematics and, more rarely, the worked material. Chopping activities were documented on two large artefacts suggesting a specific utility of those tools.     

Experimental study of aqueous fluid infiltration into quartzite: implications for the kinetics of fluid redistribution and grain growth driven by interfacial energy reduction

To investigate the kinetics of interfacial energy‐driven fluid infiltration, experiments were carried out in a quartzite–water system at 621–925°C and 0.8 GPa. Infiltration couples were made by juxtaposing presynthesized dry quartzite cylinders and fluid reservoirs. The infiltration process was confirmed by the presence of pores at the quartzite grain edges. As predicted from theoretical considerations and previous experiments, wetting fluids such as pure water and NaCl aqueous solution infiltrated into quartzite, whereas nonwetting CO₂‐rich fluids did not. Newly precipitated quartz layers at the surfaces of the infiltrated sample proved that infiltration took place by a dissolution–precipitation mechanism. The enhancement of grain growth by fluid infiltration was observed over the entire range of experimental temperatures. The fluid fraction, gauged by the porosity of the run products, increases at the infiltration front and then decreases towards the fluid reservoir to form a high‐porosity zone with a maximum porosity of 2.3–2.9%. As infiltration proceeds, the high‐porosity zone advances like a travelling wave. This porosity wave is probably caused by a grain curvature gradient resulting from preferential grain growth in the infiltrated part of the quartzite, perhaps combined with other factors. The infiltration kinetics were modelled with a steady‐state diffusion model over the high‐porosity zone. The solubility difference between dissolving and precipitating grains was deduced to be 2 × 10^?2?3 × 10^?1 wt %. The experimentally obtained infiltration rate of aqueous fluid in the steady‐state diffusion regime (2 ± 0.5 × 10^?8 m sec^?1 at 823°C) is much faster than the estimated metamorphic fluid flux rates, so that interfacial energy‐driven fluid redistribution in quartz‐rich layers could significantly contribute to the fluid flux in high‐grade metamorphism, at least over a short distance. Cathodoluminescence observations of the run products revealed that the grain growth of quartzite in the presence of fluid proceeds extensively, which would promote the chemical equilibration between fluid and rock more effectively than would volume diffusion in quartz crystals.     

Flint and Quartzite: Distinguishing Raw Material Through Bone Cut Marks

Since the 1980s, several experimental analyses have been able to differentiate some lithic tool types and some of their raw materials according to the morphology of cut marks imprinted by such tools when used for butchering activities. Thus, metal tool use has been differentiated in contexts with an abundance of lithic tools, or even the use of hand axes has been documented in carcass processing, in contrast with simple unretouched or retouched flakes. As important as this information is, there are still other important aspects to be analysed. Can cut marks produced with different lithic raw material types be differentiated? Can cut marks made with different types of the same raw material type be characterized and differentiated? The objective of this study is to evaluate if cut marks resulting from the use of different flints and different quartzites are distinguishable from each other. In the present work, an experimental analysis of hundreds of cut marks produced by five types of flint and five varieties of quartzite was carried out. Microphotogrammetry and geometric–morphometric techniques were applied to analyse these cut marks. The results show that flint cut marks and quartzite cut marks can be characterized at the assemblage level. Different types of flint produced cut marks that were not significantly different from each other. Cut marks made with Olduvai Gorge quartzite were significantly different from those produced with a set comprising several other types of quartzites. Crystal size, which is larger in Olduvai Gorge quartzites (0.5 mm) than Spanish quartzites (177–250 μm), is discussed as being the main reason for these statistically significant differences. This documented intra‐sample and inter‐sample variance does not hinder the resolution of the approach to differentiate between these two generic raw material types and opens the door for the application of this method in archaeological contexts.     

UNDER THE HAMMER: RESIDUES RESULTING FROM PRODUCTION AND MICROWEAR ON EXPERIMENTAL STONE TOOLS*

This paper presents the results of an experimental programme investigating the effects of production processes on stone tools and their interference with use‐related features. In the first part of the experimental programme, a series of flint flakes was retouched with different kinds of hammers in order to assess the extent and nature of percussion residues. After careful environmental scanning electron microscope (ESEM) observation and energy‐dispersive X‐ray (EDX) analysis, the retouched flakes were thoroughly cleaned and the underlying flint deformation was recorded. The second part of the experimental programme involved selecting several uncleaned retouched pieces for use in short woodworking, hide‐processing and butchery experiments. These pieces were observed and analysed before, during and after use. Some of the percussion features proved to be surprisingly resistant to use, and in some cases turned out to be strikingly similar in appearance to use‐generated features.     

Functional analysis of stone grinding and polishing tools from the earliest Neolithic of north-western Europe

This reconstruction of grinding, pounding, hammering and abrading activities in the Early Neolithic of north-western Europe (Linearbandkeramik and Villeneuve-Saint-Germain cultures, 5100–4700 BC) is based on the study of 1289 sandstone tools from 17 sites located in the main Paris basin river valleys (Aisne, Eure, Marne, Oise, Seine, Yonne). An original method of functional identification was elaborated, relying on observation of use-wear with a stereoscopic microscope (under120×). Identification of traces of use relied on an experimental referential of 92 samples. These include (1) grinding cereals, (2) pounding temper, colourants and various plants, (3) shaping mineral, vegetal and animal objects by polishing (schist, limestones, bone, antler, wood), (4) softening skin. A significant observation concerns the use of small handstones for grain dehusking and larger handstones for grain grinding. Recycling is a widespread feature, with multipurpose handstones and frequent reuse of lower grinding tools for obtaining colourants. A change in the function of tools can also be observed between the Linearbandkeramik and the Villeneuve-Saint-Germain.     

Micro-photogrammetric and morphometric differentiation of cut marks on bones using metal knives,quartzite, and flint flakes

In a previous article, we presented an innovative method to analyze cut marks produced with metal tools on animal bones from a metrical and tridimensional perspective (Maté-González et al. 2015). Such analysis developed a low-cost alternative technique to traditional microscopic methods for the tridimensional reconstruction of marks, using their measurements and sections. This article presents the results of an experimental study to test this photogrammetric and morphometric method for differentiating cut marks generated with metal, flint, and quartzite flakes. The results indicate statistically significant differences among cut marks produced by these three types of raw material. These results encourage the application of this method to archeological assemblages in order to establish a link between carcass processing and lithic reduction sequences on different raw materials and also to define the kind of tools used during butchery.     

Some Preliminary Observations on Subsurface Damage on Experimental and Archaeological Quartz Tools using CLSM and Dye

Lithic use-wear analysis mainly deals with use-wear features which can be observed on the surface of stone tools but a major part of the wear of brittle material is found under the surface. This wear might also be a clue to the interpretation of archaeological stone tools. In this paper we try to examine subsurface damage on experimental and archaeological quartz tools by dying them with fluorescent colour and scanning them with a CLSM. This method shows that various worked materials cause different subsurface damage, which is related to the hardness of the worked material.     

Correlation between dental occlusal wear and approximal facet length

The aim of this paper is to examine the relationship between occlusal surface wear and approximal facet length in a North American archaeological sample of modern human hunter–gatherers (n = 111) and agriculturalists (n = 123). First maxillary molars (M¹) were selected. The approximal wear facet was measured on the mesial surface of each M¹ at the widest breadth using needle tipped digital callipers. Digital images were taken of the occlusal surface and wear was recorded as the percentage of dentine exposed to the total occlusal surface. Independent age estimate was based on age‐related changes, (pubic symphysis and auricular surface). Results show the hunter–gatherers had a significantly faster rate of wear on both tooth surfaces compared to the agriculturalists in each of the four age groups. Both lifeway groups showed a positive correlation between the two tooth surfaces during the early stages of tooth wear (less than 25% occlusal wear), where the percentage of occlusal wear and the length of the approximal facet increased at a similar rate. During the middle and final stages of tooth wear (occlusal wear greater than 35%) there was a strong negative correlation between the two surfaces in both groups. It is suggested this pattern is due to the shape and function of the M¹. Both correlations were more extreme in the hunter–gatherers than the agriculturalists. When the per cent of occlusal wear exceeded 35% the length of the approximal facet started to decrease, and it is therefore recommended studies that include approximal wear exclude molars with heavy occlusal wear. Copyright © 2010 John Wiley & Sons, Ltd.     

The application of 3D‐microprofilometry as a tool in the surface diagnosis of fossil and sub‐fossil vertebrate hard tissue. An example from the Pliocene Upper Laetolil Beds,Tanzania

Non‐contact optical 3D‐profiling instruments are often used in the study of surface modifications on fossil mammalian bone. The advantage of optical laser scanning for the study of fossil and sub‐fossil bone is its non‐contact nature, allowing the investigation of fragile and poorly preserved surfaces. The high resolution and fast measuring rate of this method make it an alternative to scanning electron microscopy (SEM) investigation if topography is to be visualized. This study analyses clusters of incisions in a suid humeral fragment from the Pliocene Upper Laetolil Beds. The marks show a characteristic crest structure that is also frequently found in mandible marks produced by the Australian termite species Mastotermes darwiniensis. The marks from the Laetolil Beds are, therefore, interpreted as also being caused by insect mandible action. An as yet unknown large insect species capable of modifying bone with their mandibles is thus postulated in the palaeohabitat represented by the hominid‐bearing Upper Laetolil Beds. Copyright © 2001 John Wiley & Sons, Ltd.     

What is the use of shaping a tang? Tool use and hafting of tanged tools in the Aterian of Northern Africa

We present the results of detailed microscopic examination of tanged tools from the site of Ifri n'Ammar. The rock shelter has a particularly rich and well-preserved stratigraphy that has yielded a large variety of tanged tools, thus offering a possibility to test hypotheses on the possible links between tangs and hafting. Earlier methodological work has demonstrated that patterned wear forms on the non-active part of the tool as the result of hafted tool use, and that the characteristics of the wear traces depend on the exact hafting arrangement used. In the present study, wear analyses were combined with further experiments that involved the hafting of tanged tools with various materials and arrangements and aimed at understanding the development of this important morphological innovation. We suggest that functional data are needed to understand the relevance of the "Aterian tang" for hafting (or use), and whether this innovation was triggered by functional, cultural or environmental factors.     

QUANTIFICATION AND DISCRIMINATION OF LITHIC USE‐WEAR: SURFACE PROFILE MEASUREMENTS AND LENGTH‐SCALE FRACTAL ANALYSIS*

This experimental programme employs length‐scale analysis of measured profiles to quantitatively discriminate the surface textures of stone flakes manufactured from East Anglian chalk flint used on four contact materials (shell, wood, dry hide and soaked antler). It presents a method for evaluating texture characterization parameters based on their ability to discriminate wear types, and to determine a level of confidence to the discrimination, using the F‐test. The results of this experimental work demonstrate that relative lengths, over certain scale ranges, can discriminate the stone tool surface wear profiles produced by the different contact materials.     

Assessing the function of early hominin bone tools

Bone tools from early hominin sites in southern Africa continue to intrigue researchers interested in the development of early human technology and cognition. Sterkfontein, Swartkrans and Drimolen have all yielded bone tools dated to between 1 and 2 Mya associated with numerous Paranthropus robustus and few early Homo remains. The bone tools are described by different authors as implements used to excavate tubers from the ground and termites from their nests, work hides and strip bark from trees. The purpose of this research was to develop a more powerful analytical tool for the study and interpretation of bone surface modifications in general, and early hominin bone tool function(s) in particular. We used an optical interferometer to scan the worn areas of a sample of bone tools from Swartkrans and Drimolen, an ethnographic collection of implements used for defleshing marula fruits, and a set used experimentally to excavate in the ground and in termite mounds. The 3D rendering of archaeological and experimental wear patterns better highlights previously described differences between these patterns, and demonstrates the pertinence of this analytical tool to visually discriminating between different bone modifications. Analysis of selected 2D and 3D roughness variables indicates that the wear pattern on the early hominin bone tools from Drimolen is significantly different from that of tuber digging, very similar to termite foraging, and not unlike marula fruit processing. Marked differences are detected between the Swartkrans and Drimolen wear patterns, which suggests that the tools from these sites may have been used with different motions, in contact with abrasive particles of different size, or in different tasks. Principal component analyses conducted on 2D and 3D variables suggest that early hominin bone tools from southern Africa may have been used to forage for termites, extract tubers in a motion parallel to the tool main axis, process fruits and conduct other, as yet unidentified, tasks.     

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.     

An experimental ethnoarchaeological approach to understanding the development of use wear associated with the processing of river cane for split-cane technology

Southeastern Indians have been using cane (Arundinaria spp.) for basketry and matting for thousands of years. Unfortunately, it is only under extraordinary preservation conditions that such items survive archaeologically. Inferring the production of split-cane technology requires an understanding of prehistoric manufacturing and processing techniques. It is hypothesized that stone tools were once used to process cane for use in split-cane technologies. In the Southeast, it is not uncommon to find stone tools with traces of plant use; however attributing wear to specific plants has been problematic. Pilot experiments, grounded on ethnoarchaeological observations, were conducted with river cane (Arundinaria gigantea) in collaboration with expert basket weavers in the Cherokee Nation. The experimental ethnoarchaeological program was designed to test the efficiency of stone tools in cane processing and document use wear through microscopic observations. The results found that non-retouched flakes were efficient for processing river cane and that the different stages of splint preparation resulted in the differential development of use-related wear. Additional experimentation with river cane is necessary to better define use wear and establish criteria for identification in archaeological contexts. Nonetheless, the collaborative and experimental approach undertaken demonstrated the utility of combining traditional archaeological methods with experimentation, ethnoarchaeology, and tribal knowledge.     

Discrimination of Ceramic Surface Finishing by Vertical Scanning Interferometry

Finishing techniques are significant markers of the technological ‘know‐how’ involved in the production of the traditional, clay‐based ceramic ware. In order to provide a reliable tool to discriminate among two main surface processing techniques—that is, smoothing and burnishing—vertical scanning interferometry (VSI), a recently developed non‐destructive technique for analysing the surface roughness and topography, is applied. The smoothed areas have an obvious roughness expressed by linear structures. The latter are made of parallel ridges and trenches with an average depth of 15–20 μm. Burnishing leads to a lower topography and a lower roughness compared to the smoothed surface section. VSI quantifies the spatial distribution of the surface building blocks, which consist of phyllosilicate aggregates of variable size. The statistical treatment of the roughness data obtained by VSI shows that the surface topography provides significant information on the pottery processing and a clear qualitative and quantitative discrimination between different surfaces. VSI supports the reconstitution of the chaîne opératoire for traditional ceramic pottery and the recognition of the surface finishing techniques.     

Tooth Wear Related to Marine Foraging,Agro‐Pastoralism and the Formative Transition on the Northern Chilean Coast

Occlusal surface wear scores were examined in a sample of 200 Formative period (1500 bc–ad 500) skeletons from the lower Azapa Valley in northwest Chile. Wear rate and plane (angle) were additionally evaluated using a subsample of paired first and second mandibular molars. The Formative period represents the transition from marine foraging to agro‐pastoral dependence in the region, and differences in oral pathology indicate that diet varied by site location (coast vs valley interior) but not by archaeological phase (early vs late). We predicted that occlusal wear would demonstrate similar patterns, resulting from differences in food consistency, and therefore hypothesised that in coastal groups consuming greater quantities of foraged foods, occlusal surfaces should wear faster and exhibit flat molar wear, whereas among valley interior groups consuming greater quantities of agro‐pastoral products, these should wear slower but exhibit more angled molar wear. Heavier posterior tooth wear was identified among coastal residents, but rate and angle of molar occlusal attrition did not differ significantly by location. Heavier overall wear and a steeper molar wear plane were identified during the early phase indicating that food consistency varied somewhat over the course of the Formative period. Overall, the results indicate that, although limited differences in tooth wear exist by site location, wear varied more over time likely reflecting a gradual transition from foraging to agro‐pastoral dependence in the lower Azapa Valley. Although oral health indicators point to differences in dietary investment by location, maintenance of a mixed subsistence economy likely sustained a comparative consistency of foodstuffs. Copyright © 2011 John Wiley & Sons, Ltd.