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- Evaluating the microscopic effect of brushing stone tools as a cleaning procedurePublication . Pedergnana, Antonella; Calandra, Ivan; Bob, Konstantin; Gneisinger, Walter; Paixão, Eduardo; Schunk, Lisa; Hildebrandt, Andreas; Marreiros, JoaoCleaning stone tool surfaces is a common procedure in lithic studies. The first step widely applied at any archeological site (and/or at field laboratories) is the gross removal of sediment from the surfaces of artifacts. Lithic surface alterations due to mechanical action applied in wet or dry cleaning regimes have never been examined at a microscopic scale. This could have important implications in traceology, as any modern surface modifications inflicted on archeological artifacts might compromise their functional interpretations. The current trend toward quantification of use-wear traces makes the testing even more important, as even slight, apparently invisible surface alterations might be measured. In order to evaluate the impact of common cleaning procedures, we undertook a controlled experiment. The main aim of this experiment was to assess the effects that brushing actions applied for removing sediment particles have on flint and quartzite surfaces. All surfaces were analyzed with confocal microscopy before and after having been brushed to quantify possible changes in the micro-topography. Surface roughness parameters (ISO 25178-2 among others) were applied. Nine parameters changed significantly when mechanical actions were applied to lithic surfaces, meaning that some changes in the surface micro-topography were detected. Therefore, archeologists need to be cautious when applying prolonged mechanical actions for cleaning archeological stone tools.
- Rethinking use-wear analysis and experimentation as applied to the study of past hominin tool usePublication . Marreiros, Joao; Calandra, Ivan; Gneisinger, Walter; Paixão, Eduardo; Pedergnana, Antonella; Schunk, LisaIn prehistoric human populations, technologies played a fundamental role in the acquisition of different resources and are represented in the main daily living activities, such as with bone, wooden, and stone-tipped spears for hunting, and chipped-stone tools for butchering. Considering that paleoanthropologists and archeologists are focused on the study of different processes involved in the evolution of human behavior, investigating how hominins acted in the past through the study of evidence on archeological artifacts is crucial. Thus, investigat ing tool use is of major importance for a comprehensive understanding of all processes that characterize human choices of raw materials, techniques, and tool types. Many functional assumptions of tool use have been based on tool design and morphology according to archeologists’ interpretations and ethnographic observations. Such assumptions are used as baselines when inferring human behavior and have driven an improvement in the methods and techniques employed in functional studies over the past few decades. Here, while arguing that use-wear analysis is a key discipline to assess past hominin tool use and to interpret the organization and variability of artifact types in the archeological record, we aim to review and discuss the current state-of-the-art methods, protocols, and their limitations. In doing so, our discussion focuses on three main topics: (1) the need for fundamental improvements by adopting established methods and techniques from similar research fields, (2) the need to implement and combine different levels of experimentation, and (3) the crucial need to establish standards and protocols in order to improve data quality, standard ization, repeatability, and reproducibility. By adopting this perspective, we believe that studies will increase the reliability and applicability of use-wear methods on tool function. The need for a holistic approach that combines not only use-wear traces but also tool technology, design, curation, durability, and efficiency is also debated and revised. Such a revision is a crucial step if archeologists want to build major inferences on human decision making behavior and biocultural evolution processes.
- The effect of numerical aperture on quantitative use-wear studies and its implication on reproducibilityPublication . Calandra, Ivan; Schunk, Lisa; Bob, Konstantin; Gneisinger, Walter; Pedergnana, Antonella; Paixão, Eduardo; Hildebrandt, Andreas; Marreiros, JoaoMany archeologists are skeptical about the capabilities of use-wear analysis to infer on the function of archeological tools, mainly because the method is seen as subjective, not standardized and not reproducible. Quantitative methods in particular have been developed and applied to address these issues. However, the importance of equipment, acquisition and analysis settings remains underestimated. One of those settings, the numerical aperture of the objective, has the potential to be one of the major factors leading to reproducibility issues. Here, experimental flint and quartzite tools were imaged using laser-scanning confocal microscopy with two objectives having the same magnification but different numerical apertures. The results demonstrate that 3D surface texture ISO 25178 parameters differ significantly when the same surface is measured with objectives having different numerical apertures. It is, however, unknown whether this property would blur or mask information related to use of the tools. Other acquisition and analyses settings are also discussed. We argue that to move use-wear analysis toward standardization, repeatability and reproducibility, the first step is to report all acquisition and analysis settings. This will allow the reproduction of use-wear studies, as well as tracing the differences between studies to given settings.
- Using mechanical experiments to study ground stone tool use: exploring the formation of percussive and grinding wear traces on limestone toolsPublication . Paixão, Eduardo; Pedergnana, Antonella; Marreiros, Joao; Dubreuil, Laure; Prévost, Marion; Zaidner, Yossi; Carver, Geoff; Gneisinger, WalterGround Stone Tools (GST) have been identified in several Levantine archaeological sites dating to the Middle Paleolithic. These tools, frequently made of limestone, are often interpreted based on their morphology and damage as having been used for knapping flint, and sometimes for breaking animal bones or processing vegetal materials as well. However, the lack of experimental referential collections on limestone is a major obstacle for the identification of diagnostic traces on these types of tools and raw material. In this sense, the understanding of the specific function of these GST and the association between tool types and activity often remains unknown or merely speculative. Recent discoveries at the site of Nesher Ramla revealed one of the largest Middle Paleolithic assemblages of limestone GST. Our use-wear analysis has identified several types of both macro and micro-wear traces on different tools. Such diversity highlights the need for developing an experimental reference collection that can enable detailed comparison between experimental and archaeological use-wear evidence. In this paper, we present the results of mechanical experiments specially designed to understand and quantify major characteristics of macro and micro use-wear traces on limestone GST as a result of three main activities: 1) animal bone breaking, 2) flint knapping and 3) grinding acorns. This study pursues three main goals: a) improving our ability to distinguish natural from anthropogenic alterations on limestone; b) identifying and characterizing differences between wear-traces (macro and micro) produced by different activities, and c) building a reference collection for thorough comparisons of use-wear and residues on archaeological tools. Our results indicate that it is possible not only to identify anthropogenic alterations but also to specifically distinguish the use-wear traces formed on limestone as result of percussive activities of bone and flint. This is shown by controlled experiments allowing variables other than the worked material to remain constant. This study aims to contribute towards establishing an experimental and multi-scale library of use-wear traces on limestone.
- The Middle Paleolithic ground stones tools of Nesher Ramla unit V (Southern Levant): A multi-scale use-wear approach for assessing the assemblage functional variabilityPublication . Paixão, Eduardo; Marreiros, Joao; Dubreuil, Laure; Gneisinger, Walter; Carver, Geoff; Prévost, Marion; Zaidner, YossiIn the archaeological record, Ground Stone Tools (hereafter GST) represent an important tool group that provides invaluable data for exploring technological development and changes in resource exploitation over time. Despite its importance, Lower and Middle Paleolithic (MP) GST technology remains poorly known and understudied. The MP record of the Levant constitutes a compelling case study for exploring the nature and character of GST technology. Especially the site of Nesher Ramla (Israel, end of Marine Isotope Stage 6/beginning of 5) has provided one of the world's largest GST assemblages from MP contexts. Aiming at evaluating the variability of tool types at the site from a technological and functional perspective, this study follows an analytical approach which integrates different scales of analysis. Our workflow seeks to generate and combine qualitative and quantitative data allowing: 1) the identification of damage areas, and 2) functional analysis, based on the location, distribution, and characterization of use-wear traces. This study shows a substantial level of diversification in resource exploitation (e.g., mineral, hard animal material and likely perishable components). Results show the presence of several tool types on which diagnostic use-wear can be associated with different activities. Importantly, our analysis indicates the presence of various hammerstone types showing distinct wear characteristics. The variability observed within the hammerstones likely reflects different functions, including in some cases the processing of distinct worked materials. Ultimately, this study contributes to our understanding of the significance of GST technology for the ecological dynamics of MP populations.