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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.
- Territory and abiotic resources between 33 and 15.6 ka at Vale Boi (SW Portugal)Publication . Pereira, Telmo; Bicho, Nuno Gonçalo Viana Pereira Ferreira; Cascalheira, João; Infantini, Leandro; Marreiros, Joao; Paixão, Eduardo; Terradas, XavierThe environmental shifts during the Late Pleistocene had major influences in the landscape and, consequently, in the available resources. This had direct impact on human behavior and ecology, requiring people to constantly adjust to new economical conditions. In coastal areas, the retreat of the shoreline during the colder phases might have made available presently underwater raw material sources in the form of outcrops and gravels, eventually making it easier to gather lithic raw materials.In this paper, we present our preliminary results on the diachronic variability of raw materials in Vale Boi. Vale Boi is a coastal site, located 2.5 km from the present coastline, in the margins of a freshwater stream. The site has three different loci, all rich in lithics, fauna (including marine), bone tools, adornments, charcoal, and ochre, and evidence of continuous human occupation from c. 33 to 15.6 ka cal BP. This chronostratigraphic record makes it a perfect study case for the understanding of coastal populations' behavior and economy throughout the Upper Paleolithic.Our objective is to infer the territory of resources exploitation, landscape, and economic patterns. Raw material sources are usually fixed points on the landscape (in contrast to other resources such as fauna and flora) and, therefore, are one of the best ways of understanding how people moved in the landscape and, consequently, to infer past human behavior. We used a macroscopic approach in both the archaeological and the geological record in order to correlate sources and artifacts. Despite the absence of detailed quantitative data on each chert type, our results show that the hunteregatherers who occupied Vale Boi during the Upper Paleolithic not only used several raw materials but also a variety of sources of the same raw material. This happened both diachronically and synchronically, suggesting that not only the complete sequence as well as each archaeological layer seem to have had a considerable economic complexity with the use of adjacent and distal sources. With this paper, we aim to present updated information on the variability of raw materials at Vale Boi, including the chert assemblages, along with new chert sources in order to establish a basis for a future detailed study on the raw material sourcing at the site. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.
- 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.
- Technology, use-wear and raw material sourcing analysis of a c. 7500 cal BP lithic assemblage from Cabeco da Amoreira shellmidden (Muge, Portugal)Publication . Paixão, Eduardo; Marreiros, Joao; Pereira, Telmo; Gibaja Bao, Juan; Cascalheira, João; Bicho, NunoThe onset of the Holocene is marked by new human ecological adaptations that are associated with the origins of the Mesolithic in the Atlantic Iberia coast. During the Mesolithic, shellmidden deposits become one of the most relevant and interesting prehistoric archeological contexts, interpreted has the result of intensive human ecological exploitation, and marked by new settlement and mobility patterns, and subsistence strategies. Based on techno-typological patterns and artifact density, each Muge shellmidden has been traditionally linked to a single and specific functionality, possibly reflecting the presence of different stylistic/ethnic groups in the territory. Therefore, characterizing settlement, mobility, site function, and technological patterns in each shellmidden is fundamental to understand the archeological record and answer major questions related to human ecological behavior during the onset of the new Holocene climatic setting. This paper presents new data on the Mesolithic from the Tagus valley, using the case study of the lithic assemblage from layer 2 of Cabeco da Amoreira shellmidden. From our interpretation, by combining lithic raw material characterization and sourcing, techno-typological and use-wear analysis, this study aims to represent an important step on understanding resource exploitation, technological systems and site function, in order to address intra and inter-site variability. In what concerns lithic raw materials, they can be found in the Pleistocene gravels that compose the upper section of the Cenozoic deposits of the River Tagus, including those underneath the site. Nevertheless, the geochemical results suggest that the chert used has correspondence with local, regional, and exogenous areas. In sum, by characterizing the Cabeco da Amoreira shellmidden lithic assemblage, results and data aim to contribute to the discussion and new interpretations on shellmiddens' function and settlement occupation patterns during the Mesolithic.
- 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.