38 research outputs found

    Rectangular Beads from the Final Gravettian Level of the Abri Pataud: Raw Material Identification and its Archaeological Implications

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    The Final Gravettian level (level 2) of the abri Pataud (Dordogne, France) yielded a large assemblage of body ornaments that consists essentially of 85 quite standardized rectangular beads. Some uncertainty remained about the raw material in which these small beads were made: mammoth ivory, reindeer antler or bone? Non-invasive methods were employed in order to determine the raw material. First chemical analyses using microbeam Proton Induced X-ray Emission analysis (microPIXE) did not enable us to conclude definitively. Therefore, synchrotron and laboratory X-ray microtomography (microCT) were applied on eight beads and allowed us to identify ivory for all of them except for one, which shows slightly different morphological features.Le niveau 2 (Gravettien final) de l’abri Pataud (Dordogne, France) a livré un nombre important d’éléments de parure. L’essentiel (n : 85) correspond à des perles rectangulaires assez standardisées. Certaines incertitudes demeuraient sur leur matière première : ivoire de mammouth, bois de renne ou os ? Des méthodes non-invasives ont alors été employées pour déterminer la nature précise de celles-ci. Les analyses élémentaires par spectrométrie d’émission X induite par particules (PIXE) n’ayant pas été concluantes, la microtomographie de rayons X en laboratoire et au synchrotron a été utilisée sur huit perles et a permis d’identifier le matériau comme étant de l’ivoire, excepté pour l’une d’entre elles qui présente quelques légères différences de structure

    L'occupation humaine de l'abri Pataud (Les Eyzies-de-Tayac, Dordogne) il y a 22 000 ans : problématique et résultats préliminaires des fouilles du niveau 2

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    In this paper, we present the first elements of response to the question: "What is the status of the human remains in the Final Gravettian Level (Level 2) at Abri Pataud?" In 2005, more than forty years after the excavations of H. L. Movius, a new project concerning level 2 was initiated at Abri Pataud. This project was conceived according to three simultaneous and complementary approaches: 1) a detailed analysis of archives; 2) a study of the Movius collections; 3) a new excavation with both archaeological and geoarchaeological objectives. The initial results of the 2005 and 2006 excavations have confirmed that we can indeed appreciably improve our understanding of this archaeological level. Certain elements, such as the presence of very small backed bladelets, already permit us to more precisely define the originality of this culture. A first approach to the human remains (more than 250, MNI=6) led us to consider the hypothesis of a "disturbed primary burial". This hypothesis is confirmed by preliminary results concerning the significant assemblage of "particular artefacts" associated with the human remains, most notably mammoth ivory beads.Cet article présente les premiers éléments de réponse à la question : " Quel est le statut des vestiges humains du Gravettien final (niveau 2) de l'abri Pataud ? ". En 2005, plus de quarante ans après l'arrêt des fouilles de H. L. Movius, a débuté une opération archéologique programmée portant sur le niveau 2 de l'abri Pataud. Cette opération a été conçue selon trois démarches simultanées et complémentaires : 1) analyse des archives ; 2) étude des collections Movius ; 3) reprise de la fouille elle-même, dans une double perspective archéologique et géoarchéologique. Les premiers résultats obtenus en 2005 et 2006 ont confirmé que nous pouvions sensiblement améliorer la compréhension de ce niveau archéologique. Nous avons d'ores et déjà des éléments permettant de mieux documenter ce faciès culturel original, comme par exemple la présence de lamelles à dos de dimensions millimétriques. Une première approche des vestiges humains (plus de 250 restes, NMI = 6), nous a conduits à envisager l'hypothèse de " dépôts primaires remaniés ". Cette hypothèse est confortée par l'analyse préliminaire de l'importante série d'" objets particuliers " associée aux restes humains, notamment des perles en ivoire de mammouth

    B016 Impact of a 14-night intermittent hypoxia (IH) exposure on metabolic and cardiopulmonary adaptations to exercise in healthy subjects

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    IntroductionModifications in exercise tolerance have been reported in obstructive sleep apnea (OSA) patients. Also specific mechanisms have been speculated related to intermittent hypoxia (IH), hypertension, obesity or metabolic disturbance associated to OSA may play a significant role in exercise limitation. In order to eliminate these confounding factors we aimed to evaluate the effects of IH exposure during 14 nights in healthy subjects on exercise capacity, cardio-respiratory response and substrate oxidation during exercise.Methods12 healthy subjects (BMI: 21.8 0.5kg.m-2) were exposed to repetitive sequences of hypoxia — re-oxygenation during sleep in a hypoxic tent with appropriate cyclic re-oxygenation (rate: 30 desaturations.h-1). Maximal and sub-maximal exercise tests were performed before and after exposure in order to investigate cardiorespiratory variables and substrate oxidation parameters.ResultsIH did not modify maximal exercise parameters (VO2, heart rate, power output) nor ventilatory threshold (VTh). But this was achieved with a significant PETCO2 reduction and a VE/VCO2 increase during both maximal (Pre IH vs Post IH at VTh and Max, p<0.05) and sub-maximal (Pre vs Post at 30 % and 60 % Pmax, p<0.05) exercise tests, indicating hyperventilation. At the 1st min recovery after submaximal exercise test, diastolic arterial blood pressure (DBP) was higher after IH exposure (Pre: 60±3 vs Post: 78±2mmHg) in favour of a delayed DBP recovery following acute exercise. During sub-maximal exercise, subjects reached maximal lipid oxidation at higher power output and presented a decreased blood lactate at the same percentage of relative power after IH exposure.ConclusionExposure to 14 days of nocturnal IH is associated with an increased ventilatory response to subsequent exercise at sea level. Furthermore, delayed DBP recovery after exercise is in favor of early IH-induced cardiovascular modifications. This observation related to muscular exercise adaptations confirms the efficacy of the model in reproducing early cardiovascular alterations occurring in OSAS. Moreover, this model induces metabolic adaptations as soon as 14 nights of exposure

    An improved chronology for the Middle Stone Age at El Mnasra cave, Morocco

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    North African coastal Middle Stone Age (MSA) sites are key to study the development and expansion of early H. sapiens. El Mnasra cave on the Atlantic coast of Morocco (Témara region) is a crucial site associated with MSA archaeological materials considered advanced cognitive hallmarks of behavioural innovation, such as numerous Nassariidae perforated shells, hematite pigments, bones industry and coastal resources exploitation. We provide new trapped-charges dates (OSL and combined US-ESR ages). Our Bayesian modelling strengthens the new lithostratigraphic interpretation of the cave stratigraphic units (US) and we propose an updated chronostratigraphic model for the Middle Stone Age archaeo-sequence of El Mnasra Cave. We confirm a human presence between 124–104 ka, earlier than what the previous OSL and US-ESR data showed. Our time range intervals allowed us to also extend the age of the MSA occupations considerably to the MIS 4/3 (~62–30 ka), marked by the disappearance of the Nassariidae perforated shells. Outstandingly, our model pushed back the age of the largest record of Nassariidae perforated shells and placed the age of their use by the Aterian groups at El Mnasra from the MIS 5d-5b (~115–94 ka)

    90,000 year-old specialised bone technology in the Aterian Middle Stone Age of North Africa

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    The question of cognitive complexity in early Homo sapiens in North Africa is intimately tied to the emergence of the Aterian culture (~145 ka). One of the diagnostic indicators of cognitive complexity is the presence of specialised bone tools, however significant uncertainty remains over the manufacture and use of these artefacts within the Aterian techno-complex. In this paper we report on a bone artefact from Aterian Middle Stone Age (MSA) deposits in Dar es-Soltan 1 cave on the Atlantic coast of Morocco. It comes from a layer that can be securely dated to ~90 ka. The typological characteristics of this tool, which suggest its manufacture and use as a bone knife, are comparatively similar to other bone artefacts from dated Aterian levels at the nearby site of El Mnasra and significantly different from any other African MSA bone technology. The new find from Dar es-Soltan 1 cave combined with those from El Mnasra suggest the development of a bone technology unique to the Aterian

    Limpet Shells from the Aterian Level 8 of El Harhoura 2 Cave (Témara, Morocco): Preservation State of Crossed-Foliated Layers

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    International audienceThe exploitation of mollusks by the first anatomically modern humans is a central question for archaeologists. This paper focuses on level 8 (dated around * 100 ka BP) of El Har-houra 2 Cave, located along the coastline in the Rabat-Témara region (Morocco). The large quantity of Patella sp. shells found in this level highlights questions regarding their origin and preservation. This study presents an estimation of the preservation status of these shells. We focus here on the diagenetic evolution of both the microstructural patterns and organic components of crossed-foliated shell layers, in order to assess the viability of further investigations based on shell layer minor elements, isotopic or biochemical compositions. The results show that the shells seem to be well conserved, with microstructural patterns preserved down to sub-micrometric scales, and that some organic components are still present in situ. But faint taphonomic degradations affecting both mineral and organic components are nonetheless evidenced, such as the disappearance of organic envelopes surrounding crossed-foliated lamellae, combined with a partial recrystallization of the lamellae. Our results provide a solid case-study of the early stages of the diagenetic evolution of crossed-foliated shell layers. Moreover, they highlight the fact that extreme caution must be taken before using fossil shells for palaeoenvironmental or geochronological reconstructions. Without thorough investigation, the alteration patterns illustrated here would easily have gone unnoticed. However, these degradations are liable to bias any proxy based on the elemental, isotopic or biochemical composition of the shells. This study also provides significant data concerning human subsistence behavior: the presence of notches and the good preservation state of limpet shells (no dissolution/recrystallization, no bioerosion and no abrasion/fragmentation aspects) would attest that limpets were gathered alive with tools by Middle Palaeolithic (Aterian) populations in North Africa for consumption

    A refined chronology for the Gravettian sequence of Abri Pataud

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    Abri Pataud (France) is the type site in studies focusing on the appearance of modern humans and the development of classic Upper Paleolithic technocomplexes in Europe. It contains important evidence of successful adaptation strategies of modern humans to new territories and in response to sharply changing climatic conditions that characterized Marine Isotope Stages 3 and 2. Despite being for decades one of the best excavated and most studied Paleolithic sites, the chronology of Abri Pataud has lacked precision and revealed large discrepancies. The chronology of the lowermost part of the sequence (Levels 14–5) was refined in 2011 with the publication of 32 new radiocarbon determinations, mainly from the Aurignacian levels. In contrast, the Gravettian levels (Levels 5–2) remained poorly dated until now. Here, we present 18 new radiocarbon dates on cut-marked animal bones from the Gravettian part of the site, which complete the dating of this important sequence. The determinations are analyzed using Bayesian statistical modeling, and the results allow us to place the start of the Gravettian at the site between ∼33,000 and 32,000 cal BP (∼29,000–28,000 BP). We discuss the succession of the Gravettian facies across the sequence (Bayacian, Noaillian, Rayssian), as well as the likely duration of each archaeological level. With a total of more than 50 radiocarbon determinations, Abri Pataud offers secure information for the appearance and development of the technocomplexes linked with early modern humans and their establishment in western Europe. Based on published genetic data, it appears that it is the Gravettian hunter-gatherers and subsequent human groups, rather than the earlier Aurignacian and pre-Aurignacian groups, that contributed to the genetic signature of later and living Europeans. Hence, elucidating the precise timing of the Gravettian appearance has broad implications in our understanding of late human evolution across Europe. © 2020 Elsevier Ltd1. Introduction 1.1. Sedimentary context and natural evolution of Abri Pataud 1.2. Gravettian archaeological sequence Level 5: Early Gravettian Level 4: Middle Gravettian (or Noaillian/Rayssian) Level 3: Recent Gravettian Level 2: Final Gravettian 1.3. Previous chronology 2. Materials and methods 2.1. Radiocarbon dating 2.2. Bayesian modeling 3. Results 4. Discussion 4.1. Span and duration of the Gravettian at Abri Pataud 4.2. The Aurignacian to Gravettian transition at Abri Pataud and in western Europe 4.3. Level 5 and the earliest Gravettian of Abri Pataud 4.4. Comparison of Abri Pataud Level 5 with other Early Gravettian sequences 4.5. The Middle Gravettian occupation of Level 4 4.6. Observations on the Recent Gravettian (Level 3) and the Final Gravettian (Level 2) 4.7. The Gravettian genetic legacy 5. Conclusion

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