Browsing by Author "Paixão, Eduardo"
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- EcoPLis a pré-história no Rio Lis, da serra ao AtlânticoPublication . Pereira, Telmo; Carvalho, Vânia; Holliday, Trenton; Paixão, Eduardo; Monteiro, Patrícia; Évora, Marina; Marreiros, Joao; Assis, Sandra; Nora, David; Matias, Roxane; Simões, CarlosOur research focuses on the use of valleys that link the inland to the coast during Prehistory. Traditionally, research has studied rivers, coast and inland as separate landscapes, but the major characteristic of hunter-gatherers was mobility. In order to understand and reconstruct the evolution of human behaviour, our main goal is to answer the questions: “How, why and when did people circulate between these different ecological landscapes?” and “What was the impact of the major climatic shifts on that mobility?” To answer these questions our archaeological project includes survey, testing, and the excavation of archaeological sites, using high-resolution field and laboratory methodologies in order to contribute significantly to the understanding of ecological behaviour of Prehistoric populations, including extinct human species such as Neanderthals.
- 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.
- Evidence of specialized resource exploitation by Modern Humans in Western Iberia associated to Pleistocene and Holocene extreme environmental conditionsPublication . Pereira, Telmo; Monteiro, Patrícia; Paixão, Eduardo; Nora, David; Évora, Marina; Simões, Carlos; Detry, Cleia; Assis, Sandra; Carvalho, Vânia; Holliday, TrentonThroughout prehistory, landscapes were repeatedly subjected to both global and localized climatic fluctuations that changed the regional environments where human groups lived. This instability demanded constant adap-tation and, as a result, the functionality of some sites changed over time. In this light, the western coast of Iberia represents an exceptional case study due to the proximity between at least some oceanic cores and archaeological sites, which should facilitate an accurate reconstruction of the re-lationships between paleoenvironmental conditions and the coeval patterns of human behavior. This region, and in particular the valley of the River Lis, is marked by wide exposed plateaus cut by narrow and deep canyons. In this paper we present the stratigraphic, archaeometric, technological and archaeobotanical record of Pogo Rock Shelter, located in one of these canyons, which hints at the human responses to such changes, and discuss the link between its Solutrean and Epipaleolithic occupations to specific activities. During the coldest part of the Last Glacial Maximum, we hypothesize that there was intensive exploitation of a chert outcrop above the roof to produce blades and Solutrean tips. Later, during Bond Event 6, after that outcrop had been exhausted, there was intensive consumption of shellfish gathered between the mouth of the canyon and the sea. We hypothesize that these strikingly different roles demonstrate how hunter-gatherers adapted to local conditions, and exploited specific resources, promising to provide a better understanding about its functional role during specific extreme climate events.
- Incised stone artefacts from the levantine middle palaeolithic and human behavioural complexityPublication . Goder-Goldberger, Mae; Marreiros, Joao; Paixão, Eduardo; Hovers, ErellaIn recent years, archaeological research has demonstrated the presence of abstract non-utilitarian behaviour amongst palaeolithic hominins, fuelling discussions concerning the origin and implications of such complex behaviours. A key component in these discussions is the aesthetic and symbolic character of intentionally incised artefacts. In this study, we emphasize the geometry of the incisions as clues to intentionality. Using 3D surface analysis, we characterised incisions found on a Levallois core from Manot cave, and on a flake and retouched blade from Amud cave. In addition, we applied the same methodology to the previously published engraved Levallois core from Qafzeh and the plaquette from Quneitra. The incisions on the Manot, Qafzeh and Quneitra artefacts show similar geometric characteristics. Notably in each of these cases, the incisions form patterns that align with the artefact's surface topography and shape. In contrast, the incisions on the Amud artefacts are shallower, with no clear orientation or patterning. The methodology applied thus creates a comparative context for MP incised items, reinforcing the interpretation of the Manot, Qafzeh and Quneitra artefacts as deliberate engravings, whereas the marks on the items from Amud are consistent with their functional use as abraders. While the Qafzeh, Quneitra and Manot items are isolated initiatives in their chronological and geographic contexts, the shared traits of the intentional engravings underscore their predetermined nature.
- New Insights on an Old Excavation: Re-visiting the Late Middle Palaeolithic Site of Far’ah II, North-western Negev, IsraelPublication . Goder-Goldberger, Mae; Gilead, Isaac; Horwitz, Liora Kolska; Sánchez-Romero, Laura; Paixão, EduardoRevisiting collections from old excavations with new research objectives and analytical tools brings them to life and integrates them into evolving models of human-landscape interactions. This paper examines hominin behaviour and adaptations at the late Middle Palaeolithic open air camp site Far'ah II, dated to similar to 49 ka by analyzing the spatial patterning of assemblages from the 1976-1978 excavation seasons. This was facilitated by the large area excavated and the fact that all lithics and most bones larger than 2.5 mm were recorded using three dimensional coordinates. Examining the refitted flint sequences highlights the use of variable technological systems, including the Levallois unidirectional convergent method. Use wear on the ground stone tools suggests they were used for knapping as well as food processing, and the faunal assemblage reflects a wide range of species that were consumed on-site. By combining lithic refitting studies and spatial mapping of artefact and bone distribution using GIS, we have dissected the occupation history and demonstrate that the living floor defined during the excavations actually consists of at least two different occupation events, that partially overlap in the central area of the site. This analysis demonstrates that Far'ah II was probably a favoured locality, revisited by Middle Palaeolithic hominins due to its proximity to a rich mosaic of habitats.
- 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.
- 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.
- 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.
- 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.
- 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.