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The European Solutrean has yielded one of the oldest chert assemblages documenting intentional heat treatment. Many questions about social and economic factors arise in this context. For example, did Solutrean knappers heat-treat only specific types of chert? Were specific heating techniques adapted to specific types of chert? We investigate these questions by analyzing 43 chert artifacts from Laugerie-Haute. We use near-infrared spectroscopy to identify heat-treated artifacts made from four different types of chart, and to estimate their heating temperatures. We identify 13/37 test pieces as heat-treated. Only 5 of these 13 pieces (38%) would have been identified as such macroscopically (based on gloss contrast). The overall magnitude of gloss, cannot be used to identify heat-treated chert artifacts. These findings have implications for future studies of the prevalence of heat-treated artifacts in Solutrean assemblages. Visual identification based on surface gloss is likely to only recognize the smaller part of heat-treated artifacts.

We have studied nanometric high aspect ratio Ag nanopillar coatings exhibiting reduced secondary electron emission for the mitigation of multipactor effect in radio-frequency space devices of high frequency and high power. The Ag nanopillars have been grown by glancing angle deposition with DC magnetron sputtering. Some samples have been covered by a gold capping layer to reduce oxidation and aging effects. The secondary emission yield of the surfaces of these samples has been measured and compared to those of flat Ag and Au reference samples. The results show that high aspect ratio surface roughness at the nanometer scale significantly reduce the secondary emission yield of the surface. This reduction is more important for low electron energies, which is the most influencing energy range of electrons for multipactor. The multipactor region for the nanopillar coating presenting the best secondary emission yield properties has been simulated, finding practical suppression of multipactor effect. The high-frequency surface resistance of these samples has also been estimated from published computations for similar surface roughness patterns. It was found that such nanopillar coatings are compatible with the best accomplishments of present space industry., This investigation has been funded by the MINECO of Spain through the AYA2012-39832-C02-02, FIS2015-67367-C2-1-P, MAT2015-69035-REDC and MAT2014-59772-C2-1-P projects and by the Comunidad de Madrid through the NANOMAGCOST-CM Ref: P2018/NMT4321 project. One of the authors (C.M.) thanks MECD for FPU14/02020 grant. The authors also want to thank SEGAINVEX and SIdI from UAM for technical support, and to acknowledge the service from the MiNa Laboratory at IMN funded by Comunidad de Madrid (S2018/NMT-4291 TEC2SPACE), MINECO (CSIC13-4E-1794) and the European Union (FEDER, FSE).

Discovered at the beginning of the twentieth century, the Abri Casserole (Dordogne, France) was the subject of salvage excavations in the early nineties. The fieldwork revealed a sequence of 13 archaeological levels that document human occupations from the Gravettian to the Magdalenian, including very rare and poorly known assemblages (e.g. Early Badegoulian, Protosolutrean) that afford a particular importance to this sequence. Results of a previous dating program that focused on the Badegoulian levels were obtained in 1994 but were neither extensively published nor discussed. Five AMS14C ages obtained for the Gravettian and Solutrean assemblages in the early 2010s served to complement the site’s chronology. However, since the beta counting ages for the Badegoulian levels were in conflict with the accepted AMS chronology for the region’s late Pleniglacial archaeological record, a new AMS dating program was implemented to renew the radiometric framework of this specific portion of the sequence. Compared to the previous beta counting measurements, the seven newly obtained AMS ages are about 1000 years older (23.3–20.5 cal ka BP) and congruent with other AMS-dated Badegoulian sequences. These results thereby restore the inter-site chronological coherence of the Solutrean–Badegoulian and Badegoulian–Magdalenian transitions.

This work presents the gas phase synthesis of CoCr nanoparticles using a magnetron-based gas aggregation source. The effect of the particle size and Co/Cr ratio on the properties of the nanoparticles is investigated. In particular, we report the synthesis of nanoparticles from two alloy targets, Co90Cr10 and Co80Cr20. In the first case, we observe a size threshold for the spontaneous formation of a segregated core@shell structure, related to the surface to volume ratio. When this ratio is above one, a shell cannot be properly formed, whereas when this ratio decreases below unity the proportion of Cr atoms is high enough to allow the formation of a shell. In the latter case, the segregation of the Cr atoms towards the surface gives rise to the formation of a shell surrounding the Co core. When the proportion of Cr is increased in the target (Co80Cr20), a thicker shell is spontaneously formed for a similar nanoparticle size. The magnetic response was evaluated, and the influence of the structure and composition of the nanoparticles is discussed. An enhancement of the global magnetic anisotropy caused by exchange bias and dipolar interactions, which enables the thermal stability of the studied small particles up to relatively large temperatures, is reported., This research was funded by the Spanish Ministry of Science, grant number RYC2018-024561-I; the National Natural Science Foundation of China, Grant Number NFSC-21850410448; The Centre for High-resolution Electron Microscopy (CħEM), supported by SPST of ShanghaiTech University under contract No. EM02161943 and NSFC- 21835002; the Spanish MINECO, grant number FIS2016-76058-C4-1-R and MAT2015-65295-R; and the Comunidad de Madrid grant number P2018/NMT-4321.

Le site de Brignol fournit un nouvel ensemble archeologique a rattacher a un facies tres restreint de l'Aurignacien recent, celui a grattoirs Caminade. Represente a l'heure actuelle de maniere significative sur seulement huit sites du Sud-Ouest francais, ce facies reste jusqu'a aujourd'hui relativement enigmatique au sein du stade recent de la macro-culture aurignacienne. S'agit-il d'un facies fonctionnel, complementaire d'un autre facies de cette meme phase chronologique, ou bien au contraire d'une entite regionale et/ou chronologique distincte ? Plusieurs facteurs compliquent l'obtention aisee d'une reponse a cette question. Tout d'abord, des problemes taphonomiques dans les sites stratifies obscurcissent notre comprehension de la relation entre les grattoirs Caminade et les autres facies de l'Aurignacien recent. D'autre part, l'absence, a ce jour, de remontages sur une telle serie nous a empeches de completer le schema operatoire existant de ce mode de production, ce qui est necessaire pour comprendre son articulation avec d'autres modes de productions connues pour cette phase. L'etude technoeconomique de la serie lithique de Brignol, des remontages et leur croisement avec des analyses technofonctionnelles, petroarcheologiques et taphonomiques, fournissent un nouveau jalon pour la comprehension de ce facies particulier. La description du schema operatoire de la production des grattoirs Caminade, les donnees traceologiques et l'analyse des possibles fonctions du site permettent d'envisager de nouvelles hypotheses a explorer au sujet du fonctionnement de ces objets et plus largement sur le statut de ce facies au sein de l'Aurignacien recent.

International audience; The use of multi-agent simulation (MAS), which were engaged as an exploration, aims to simulate potential theoretical paths of siliceous rock fragments, according to a gravity model and altimetry data from various IGN altitude databases. The objective is to identify areas where eroded siliceous rock fragments may have be concentrated. The aim is therefore to target prospecting activities on these theoretical zones to have the best chance of finding concentrations of these rock fragments. This approach is part of the work of several on going Projets Collectifs de Recherche (PCR) "Réseaux de lithothèques". One of the working axes of these projects is to improve the spatial knowledge of flint formations whose prehistoric populations were able to extract resources for their needs. Main principles of SMA and first results, obtained using NetLogo software and a gravity model, are presented and discussed.; L'utilisation présentée ici de la simulation multi-agents (SMA), qui ont été engagés de façon exploratoire, vise à simuler les parcours théoriques potentiels des fragments de roches siliceuses, selon un modèle gravitaire et des données d'altimétrie de diverses bases de données d'altitude de l'IGN. L'objectif est de permettre d'identifier des zones où les fragments de roches siliceuses érodées ont pu être concentrés. Il s'agit ainsi de cibler les actions de prospection sur ces zones théoriques pour avoir le plus de chances de retrouver des concentrations de ces fragments rocheux. Cette démarche s'inscrit dans le cadre des travaux de plusieurs Projets Collectifs de Recherche (PCR) "Réseaux de lithothèques" qui sont en cours. L'un des axes de travail de ces projets est d'améliorer la connaissance spatiale des formations à silex dont les populations préhistoriques ont pu extraire des ressources pour leurs besoins. Les grands principes de la SMA seront évoqués et des premiers résultats, obtenus à l'aide du logiciel NetLogo et d'un modèle gravitaire, sont présentés et discutés.

The rich record of Aurignacian graphic arts from sites in the Vezere Valley of SW France holds a key place in our understanding of systems of representation in the European Early Upper Paleolithic. One of the main sites yielding representational objects is Abri Cellier, which has long been on the short-list of major art-bearing sites attributed to the European Aurignacian. Collie's 1927 excavations yielded 15 engraved and/or pierced limestone blocks that have served as a key point of reference for the study of Aurignacian art in SW France. As part of a broader re-excavation of key Aurignacian sites in the Vezere Valley, we returned to Abri Cellier in 2014, with detailed archives in hand, in the hopes of finding intact deposits that would allow a better understanding of the archaeological sequence at the site and its relationship to other Aurignacian sites in the so-called "classic zone." While disappointingly little is left of the site, the 2014 season allowed the addition of 16 new engraved, painted or pierced blocks to the 15 already known from the 1927 excavations. We present here a brief history of excavations at the site, a stratigraphic analysis, an overview of archaeological materials recovered, a series of 14C ultrafiltration dates, a brief discussion of the peculiar characteristics of Aurignacian block art in SW France, a detailed analysis of the engraved surfaces of the blocks discovered in 1927 and in 2014 and finally a comparison of the newly-revised Cellier block assemblage with those from other Aurignacian sites in the Vezere.

Coastal adaptations and the exploitation of marine resources are important topics in the study of the human evolution as certain other human behaviors may be linked to them: large group size, low mobility, complex technology and wide-ranging gifting or exchange. It is therefore essential to characterize the socio-economic organization of Aterian hunter–gatherers in coastal landscapes. The example of Unit 8 of El Mnasra Cave provides some initial insights into the economic organization of Aterian groups living on the Atlantic coastal landscapes of Morocco through a combination of zooarchaeological and stone tool industry data. The lithic industries include tanged tools, which in fact encompass a mosaic of tools (points, scrapers, unmodified edges, etc.) having a long use-life and high mobility. The lithic industries also present a fragmented reduction system associated with a large range of mainly local raw materials. The lithic assemblages are thus very flexible and include multifunctional-tools. Aterian hunter–gatherers consumed a broad range of terrestrial resources (small, medium and large ungulates, tortoises) as well as coastal ones (mollusks). The artifacts (faunal remains, lithic and osseous industries, hearths, ornaments in Nassarius sp. shells pigments) reflect diverse activities, showing that El Mnasra Unit 8 is not a single-activity site. The low density of archaeological artifacts, the small number of faunal species exploited by humans and the fragmented lithic reduction system indicate brief occupations.

International audience; Signalé dès les années cinquante, le gisement quercinois du Petit Cloup Barrat a été redécouvert au milieu des années 90. Cette doline, située à 800 mètres de l'entrée préhistorique de la grotte de Pech Merle, a fait l'objet de fouilles programmées entre 2004 et 2008. Menée aux abords d'une grotte-abri localisée à l'extrémité ouest de la doline, cette opération a permis la mise en évidence de plusieurs niveaux d'occupations datant de la seconde moitié du Paléolithique supérieur. Deux secteurs ont été distingués, à partir des différentes signatures sédimentaires de la séquence stratigraphique : la zone avant, qui correspond à la partie " ouverte " de l'espace fouillé, et la zone du fond, située sous le porche. Dans la grotte, affectée par des phénomènes de soutirage karstique, le remplissage mis au jour documente une succession d'au moins trois techno-complexes distincts : la couche10N, dont l'attribution reste à confirmer, fait suite à l'ensemble 8 où se succèdent Solutréen supérieur, Badegoulien à raclettes et Magdalénien inférieur. Dans la zone avant, le Magdalénien moyen de la couche 3, remanié par la mise en culture de la doline, coiffe la couche 4, ensemble le mieux documenté à ce jour et qui fait l'objet de cet article. Riche de plusieurs milliers de vestiges, cet ensemble présente certaines particularités : si la mauvaise préservation de la faune limite l'approche archéozoologique, les données acquises lors de l'analyse des productions lithiques et osseuses apportent en revanche de nombreux éléments de discussion. La composante lithique, à travers la nature de certaines armatures et de leurs modalités de production, fait clairement écho à certaines industries du Magdalénien inférieur. Néanmoins, tandis que la plus grande part de la composante osseuse s'accorde pleinement avec cette proposition (type de pointe, extraction par rainurage longitudinal), une série de pièces témoigne de la mise en oeuvre d'un débitage du bois de renne par percussion habituellement exclu de ces ensembles. Cette " mixité " technique - qu'il conviendra de confirmer par le biais de datations directes - vient alimenter les débats actuels sur la transition badegoulo-magdalénienne. Enfin, la découverte de plusieurs incisives d'herbivores sciées et d'une ébauche d'anneau ouvert en bois de renne renforce l'originalité de l'assemblage, ouvrant de nouveaux horizons de recherches.

International audience; The Transition from Middle to Upper Paleolithic represents one of the most animated debate among prehistorians, in which the Chatelperronian (39,000-33,000 BP), last industry attributed to the Neandertalians, is of prime importance. Nevertheless, the Chatelperronian series are relatively rare, so often badly preserved and sometimes even mixed. Yet, the discussion for the chatelperronian definition has to start from undisturbed assemblages, giving to its status of “transition” industry. Thanks to its excellent state of preservation, the study of Canaule II's serie (Creysse, Dordogne) should bring new facts for the defintion of this techno-complex. This paper presents the main results achieved by taphonomical and typo-technological approaches of five lithic refittings.; Fouillé par Jean Guichard en 1968 et 1969, le site de plein air de Canaule II (Creysse, Dordogne) présente un unique niveau archéologique attribué au Châtelperronien par la présence de pièces à dos caractéristiques. Ce gisement fut interprété comme étant un atelier de débitage, directement implanté sur les gîtes de silex maestrichtien du Bergeracois. Nous le présentons ici à travers l'approche taphonomique, techno-économique et spatiale de cinq remontages lithiques. Cette étude montre l'exceptionnelle conservation du site et explore le potentiel qu'il révèle pour la définition du Châtelperronien et la caractérisation des comportements humains au début du Paléolithique supérieur.

International audience; European Mid Upper Paleolithic mortuary practices have been traditionally associated with primary burials, ochre, body ornaments and grave goods. Recently, evidence of the post-mortem treatment of skeletal remains, such as the displacement and removal of skeletal elements, has been reported for the Gravettian period in the Southwest of France. Here, we present the preliminary results of anthropological and taphonomic analyses of the human remains from the Gravettian site of Fournol (Soturac, Lot, France). We describe the first evidence of the scalping and disarticulation of human remains, a previously unknown post-mortem treatment in Gravettian contexts from the South West of France.