Search

A previously undocumented type of wetland is described from the Atacama Desert in northern Chile (3000 m above sea level), sustained exclusively by direct precipitation and perched above the regional water table. Geomorphological mapping, pedostratigraphy, geochemistry, and analysis of contemporary vegetation is used to understand wetland formation and dynamics during historical and present time periods. The paleowetland deposits overlie a Miocene tuff that acts as an impermeable barrier to water transfer and creates conditions for local shallow ground water. These deposits include several paleosols that were formed during periods when precipitation increased regionally at 7755–7300, 1270, 545, and 400–300 cal yr BP. The similarity in timing with other palaeohydrological records for the Atacama implies that paleosols from this wetland are proxies for reconstructing past changes in local and regional hydrological cycle. Archaeological investigations have revealed the presence of two small farms from the Late Intermediate period, i.e., during the earliest wetter phase represented by the paleosols. Both farms are located near the paleowetland deposits, which suggests that local inhabitants exploited these water sources during late pre-Hispanic times. Results of this study improve knowledge of settlement patterns during this and earlier cultural periods.

International audience; A database of Pleistocene periglacial features in France has been compiled from a review of academic literature and reports of rescue archaeology, the analysis of aerial photographs and new field surveys. Polygons, soil stripes, ice-wedge pseudomorphs, sand wedges and composite wedge pseudomorphs are included in the database together with their geographic coordinates, geological context, description and associated references. It is hoped that this database, which aim is to be integrated in broader studies, will stimulate further work on past permafrost reconstruction and will favour greater understanding of the climatic events that lead to the formation of the periglacial features. The database is available online on the AFEQ-CNF INQUA website (https://afeqeng.hypotheses.org/487). A folder that contains photographs and sketches of the features is also available on request.

International audience

The mid-west part of the Aquitaine basin is characterized by a vast sandy terrain, today covered by the Landes de Gascogne forest. This geological formation was recently the subject of new geomorphological and chronostratigraphic analyses, demonstrating that the formation corresponds to an erg that began to form in the early Quaternary. During the Late Glacial, the Sable des Landes was already a large natural unit in southwestern France. How did Magdalenian human groups appropriate this unique area ? And what was the impact of this desert on the mobility and exchange networks of these groups ? To date, surveys of the area have only documented two sites within this sandy desert clearly identified as belonging to the Upper Magdalenian : Tizon to the south and La Honteyre to the north. Compared with the more densely populated regions of Entre-Deux-Mers to the north and the western Pyrenees to the south, this area therefore appears to have been more constraining for hunter-gatherer groups, doubtless due to the low plant and animal biomass. The open-air site of La Honteyre, discovered in 1990 by G. Belbeoc''h and excavated between 1997 and 2000 by M. Lenoir, presents a single level with a relatively low thickness. We here propose a re-evaluation of the site in order to gain a better understanding of the technical and economic strategies implemented by Magdalenian hunter-gatherers in a sandy desert environment that was a priori constraining. In relation to previous studies, we present a qualitative evaluation of the taphonomy of the assemblage and propose a petrographic, technological, and typological analysis of the lithic remains. The results of the vertical projection of the coordinated remains, the spatial distribution of the lithic refits, and the typo-technological nature of the assemblage all indicate that the layer of remains is homogeneous. The assemblage is quite rich with a total of 25 663 lithic remains, including a significant proportion under a centimetre in size (> 15,000 items). The analysis of the siliceous raw materials indicates a supply area clearly focused northwards, in particular with the importation of roughly worked blocks transported from over 100 km away in the Charente region. Mid-distance from this (around 60 km), flint was also imported from deposits in the Dordogne. It appears that more distant materials may also have been imported (Cher Valley ?, ca. 350 km) as documented in the form of one or two objects. The high level of economic foresight illustrated by this behaviour perfectly illustrates a strategy of planning for the needs of a group that had come to occupy an area devoid of flint for blade knapping. It also highlights the importance Magdalenian groups placed on blade production. Finally, the presence of some bladelet cores made from local flint from Villagrains (15 km) shows some knowledge of the local environment. The low quantities of this flint could indicate a relatively short occupation of the site. Careful blade production has allowed blanks to be obtained for tools mainly involving pieces with lateral retouches, burins (including parrot-beak burins), bec-perçoirs and pointed blades. Blade knapping was based on raw material imported from the Charente area and the terraces of the Dordogne using the traditional methods of the period (unipolar, semi-tournant, soft organic percussion). A blade-bladelet knapping continuum used the same volume for intermediate blanks : small blades/ large bladelets. This economic objective can be observed in the presence of some original foliate lithic points (Laugerie-Basse type) and bladelets. An autonomous bladelet production complements these blanks, filling the need for blanks for hunting armatures on bladelets. Two main methods are involved in a single convergent unipolar concept for obtaining naturally pointed blanks. The backed bladelets present a typological diversity demonstrated in the manufacture of the pieces : backed, truncated, denticulated, inversely pointed, notched, and scalene triangles. Some specific objects such as certain burins and lithic points are good tracers for identifying the cultural links maintained between the occupants of La Honteyre and the sites located on either side of the Sable des Landes. Furthermore, the presence of parrot-beak burins and Laugerie-Basse points indicates clear interactions between the Vienne region and the western Pyrenees, an area that now includes the Sable des Landes thanks to the site of La Honteyre. Finally, the convergent unipolar bladelet production confirms the links between these sites and the cultural identity of these late Upper Magdalenian groups. It therefore appears that we are dealing with a site located in the heart of a cultural territory, confirmed by the widespread presence of specific objects and technical behaviour. Thus, by comparing the data from this site with other occupations to the south and north of the Sable des Landes, we can gain a better understanding of this constraining region as a place of passage for groups travelling from the north to the south, as implied by the broader circulation network of raw material between these different western Aquitaine sites., La partie centre-ouest du Bassin aquitain est caractérisée par une vaste couverture sableuse, aujourd’hui recouverte par la forêt des Landes de Gascogne. Cet espace correspond à un véritable erg sableux, dont la formation remonte au début du Quaternaire. Au cours du Tardiglaciaire, le Sable des Landes constitue déjà une grande unité naturelle au sein du Sud-Ouest de la France. Quel a été l’impact de ce désert sur la mobilité et les réseaux d’échanges des groupes humains vivant en Aquitaine au Magdalénien ? En l’état des données et malgré des prospections, seuls deux gisements bien caractérisés du Magdalénien supérieur sont connus dans ce contexte sableux : Tizon au sud et la Honteyre au nord. En l’état des découvertes, le Sable des Landes apparaît donc visiblement contraignant pour les groupes de chasseurs-collecteurs en relation sans doute avec une faible biomasse végétale et animale. La réévaluation du site de la Honteyre a pour objectif de mieux comprendre les stratégies techniques et économiques mises en oeuvre par les chasseurs-collecteurs magdaléniens dans ce contexte de désert sableux, a priori contraignant. Ce site de plein air a livré un niveau unique relativement peu dilaté mais clairement homogène. L’étude des matières premières indique une aire d’approvisionnement résolument tournée vers le nord avec en particulier l’introduction de blocs à peine dégrossis transportés depuis la Charente (> 100 km ; i. e. «grain de mil » ). Ce comportement économique prévisionnel illustre parfaitement la stratégie de planification des besoins d’un groupe venu occuper un espace dépourvu en volumes de silex suffisants pour des débitages laminaires. De plus, la présence de nucléus à lamelles en silex local (i. e. Villagrains) témoigne d’une connaissance relative de ce milieu mais soulignerait plutôt une implantation relativement courte dans ce territoire. La production lamino-lamellaire soignée a permis de fournir des supports d’outils et des armatures de chasse. Certains morphotypes permettent de préciser les liens culturels entretenus par les occupants de la Honteyre avec des gisements situés de part et d’autre du Sable des Landes. En outre, la présence de burins «bec-de-perroquet » et de pointes de Laugerie-Basse permet de tracer des relations évidentes entre la Vienne et les Pyrénées occidentales, espace intégrant désormais le Sable des Landes via ce jalon que constitue la Honteyre. De plus, une production lamellaire particulière livrant des supports naturellement pointus confirme ces liens inter-sites et appuie l’identité culturelle de ces groupes du Magdalénien supérieur récent. Ce gisement, perdu au milieu d’un erg sableux, est donc parfaitement intégré à un réseau culturel matérialisé notamment par la diffusion d’objets et de comportements techniques spécifiques. On peut alors mieux appréhender cet espace contraignant comme un lieu de passage de groupes transitant du nord au sud, comme semble l’indiquer le réseau plus large de circulation des matières premières entre ces différents gisements ouest-aquitains, lors de l’amélioration climatique du GI 1e., Gourc Laura, Langlais Mathieu, Sitzia Luca, Caux Solène, Belbeoc’h Gwénolé, Lenoir Michel. La Honteyre (Le Tuzan, Gironde) : une occupation de chasseurs-collecteurs magdaléniens en contexte de désert sableux. In: Bulletin de la Société préhistorique française, tome 113, n°4, 2016. pp. 713-735.

International audience; Detailed stratigraphic analysis and numerical dating (OSL, IRSL, ESR, 14C) of Pleistocene coversands in southwest France enable the construction of a renewed chronostratigraphic framework for sand depo-sition. The chronological data obtained from sandsheet units testify to the development of transgressive dunefields since at least the Middle Pleistocene (MIS 10). Three main phases of accumulation occurred during the Last Glacial. The oldest one (64e42 ka) is associated with wet sandsheet facies, histic horizons and zibar-type dune fields, which reflect deposition in a context strongly influenced by the groundwater table. The Late Pleniglacial (24e14 ka) corresponds to the main phase of coversand extension in a drier context. Silty gley horizons suggest, however, local interruptions of sand drifting during GS 2.1. Late-glacial stabilization of the coversands may not have occurred before GI-1c (Allerød), which was typified by the development of cumulic arenosols. These were covered by parabolic dunes during the Younger Dryas. The variations in extent of the emerged continental shelf during the glacialeinterglacial cycles may explain the uneven geographical distribution of sand deposition through time. Because of coastline retreat up to 100 km north of 45 N during the LGM lowstand, the coversands were unable to reach the northern part of the basin. Comparison with other European regions highlights stronger affinities of the French record with Portugal than with the Netherlands and Great Britain, probably because of reduced influence of permafrost.

During the last glacial period, a large part of the Aquitaine basin (southwest France) was a periglacial desert comprising coversands with low-relief dune fields surrounded by loess accumulations. OSL and radiocarbon dates show that the phase of maximum sand deposition coincides with Marine Isotope Stage (MIS) 2. Peats and gleyic palaeosoils intercalated within the sands at some sites indicate that vegetation cover was able to develop locally during short events, possibly D–O interstadials, due to raised groundwater levels in interdunal depressions. Few Palaeolithic sites have been discovered in the coversand area in contrast to the peripheral loess region. Systematic survey along a future highway corridor demonstrates that this paucity of sites is not the result of insufficient survey nor deep site burial, but rather reflects an archaeological reality. This strongly suggests that the sand area was not attractive for hunter–gatherer populations due to its reduced levels of water resources, and available vegetation and animal biomass. The distribution of cultural markers such as art items and projectile points also shows that the coversand area probably acted as a barrier separating two different cultural sub-areas, one in the Pyrenees and Cantabria, the other in the Perigord. As a consequence, the commonly accepted view that southwest France, as a whole, served as a refugia during the cold and arid phases of the Pleistocene should be replaced by a more complex one that reflects the fact that a large part of the territory was almost unoccupied and that human populations were concentrated along alluvial valleys.

National audience

International audience; The Arabian Peninsula has long been considered as a region devoid of long-term human settlement until the Holocene period, as a result of drastic climatic changes throughout the Pleistocene. It might be expected that the area was deserted during hyper-arid and arid periods, and populated by new migrant groups during humid events, according to a " push and pull " phenomenon. Although this scenario may be perfectly valid for a large part of the Peninsula, a set of recent data points to the persistence of populations in several regions, which may have served as refugia for human groups who developed their own technological traditions. Such a scenario is suggested by: (1) The succession of dense human occupations under arid conditions between ca. 60 and 50 ka, in the Wadi Surdud basin, a small sedimentary basin in the foothills of the Yemeni Western Highlands. This archaeological site complex encompasses several successive human settlements characterized by a Middle Paleolithic tradition which significantly differs from the Middle Paleolithic and Middle Stone Age contemporaneous traditions from neighboring regions; (2) The regional diversity of the Middle Paleolithic throughout the Saharo-Arabian arid belt during MIS 3, expressed by an array of local techno-typological facies that likely relate to distant and disconnected source regions where populations contracted when climate worsened. Together with a set of high-resolution archaeological contexts recently discovered in the Arabian Peninsula and dated to MIS 5, these data suggest that the major human expansion waves which occurred in the region during the Upper Pleistocene are correlated with the wet phases of MIS 5, while populations probably contracted into a few refugia areas at the beginning of MIS 3.

The recovery at Shi’bat Dihya 1 (SD1) of a dense Middle Paleolithic human occupation dated to 55 ka BP sheds new light on the role of the Arabian Peninsula at the time of the alleged expansion of modern humans out of Africa. SD1 is part of a complex of Middle Paleolithic sites cut by the Wadi Surdud and interstratified within an alluvial sedimentary basin in the foothills that connect the Yemeni highlands with the Tihama coastal plain. A number of environmental proxies indicate arid conditions throughout a sequence that extends between 63 and 42 ka BP. The lithic industry is geared toward the production of a variety of end products: blades, pointed blades, pointed flakes and Levallois-like flakes with long unmodified cutting edges, made from locally available rhyolite. The occasional exploitation of other local raw materials, that fulfill distinct complementary needs, highlights the multi-functional nature of the occupation. The slightly younger Shi’bat Dihya 2 (SD2) site is characterized by a less elaborate production of flakes, together with some elements (blades and pointed flakes) similar to those found at SD1, and may indicate a cultural continuity between the two sites. The technological behaviors of the SD1 toolmakers present similarities with those documented from a number of nearly contemporaneous assemblages from southern Arabia, the Levant, the Horn of Africa and North Africa. However, they do not directly conform to any of the techno-complexes typical of the late Middle Paleolithic or late Middle Stone Age from these regions. This period would have witnessed the development of local Middle Paleolithic traditions in the Arabian Peninsula, which suggests more complex settlement dynamics and possible population interactions than commonly inferred by the current models of modern human expansion out of Africa., The international Paleo-Y paleoanthropological research project, developed since 2005 by R.M. in agreement with the Yemeni General Organization for Antiquities and Museums (GOAM) and the Centre Français d'Archéologie et de Sciences Sociales de Sanaa (CEFAS), has been supported by the French Ministry of Foreign Affairs (to R.M.), the French CNRS Eclipse II project (to R.M.) and the L.S.B. Leakey Foundation (to A.D.). The Paleo-Y project was initiated thanks to the generous help of A. de Maigret (University of Naples) and J.-F. Jarrige (CNRS), and greatly benefited from the support of the University of Bordeaux 1 (UMR PACEA CNRS), the University of Poitiers (Department of Geosciences), the French Institut National de Recherches Archéologiques Préventives (INRAP), and also from the collaboration of the French Muséum National d'Histoire Naturelle and the University ‘La Sapienza’ of Rome. For research permission and collaboration, Paleo-Y is indebted to A. Ba-Wazir, General Director of the GOAM, A. Garallah, Deputy of the GOAM, and A.A. Mohsen, Governor of Al-Mahqwid. We acknowledge the extraordinary and continual support provided by J. Lambert and M. Tuchscherer, directors of CEFAS. The archaeological excavations at SD1 and SD2 were carried out under scientific direction of A.D. and J.J., respectively. In addition to the authors of this study, during the last years of the Paleo-Y fieldwork in Tihama, research at Wadi Surdud has benefited from contributions from E. Abbate, N. Abdulbaset, A. Abraudey, K. Al-Haj, M. Al-Halabi, A.S. Alrudy, A. Ballah, S. Boulogne, A. Coppa, E. Messager, H. Murad, M.A. Qasam, C. Thiébaut, P. Voinchet, and also received the friendly support of E.H. Awadh, A.M. Farea, I. Hehmeyer, and E. Keall, of the Granary's Museum of Zabid, and M.A. Al-Sayyani and M. Rajeh Murad of the GOAM. Additional research on the geo-mineralogical, geochemical, and paleoenvironmental aspects has been developed in France by M. Frouin, C. Hatté, A. Meunier, and A. Queffelec. M.-C. Noël and H. Goubar respectively assured most of the administrative and logistical aspects during fieldwork in Yemen. Thanks are also due to S. Antonini, S. Cleuziou, V. Eisenman, A. Froment, M.-L. Inizan, A.-M. Lézine. We are sincerely grateful to the people of the Al-Mahqwid and Tihama regions for their welcome and interest in our research and acknowledge the support of A. Auotnan, representative of the District of Khamis Bani Saad. The spatial analysis of S. Boulogne (INRAP) and F. Lacrampe-Lacuyaubère (Archéosphère), the final layout of the lithic drawings by G. Devilder (PACEA) and the editing of the text by B. Gravina (PACEA) have significantly enhanced the present paper. Our study has greatly benefited from the comments of R. Dennell, F. d’Errico, D. Begun, the JHE associate editor, and the suggestions of three anonymous reviewers.

La revue des données issues de l'archéologie préventive et programmée, des descriptions de coupes naturelles ou des photos aériennes conduit à recenser plusieurs centaines de structures périglaciaires dans le Sud-Ouest de la France. Plusieurs catégories sont distinguées : 1) réseaux de polygones supradécamétriques correspondant à des coins à remplissage sableux primaire ou mixte, 2) coin à remplissage sableux primaire et, 3) réseau de petits polygones correspondant à des fentes de gel à maille semi-métriques à métriques. La datation OSL du remplissage de plusieurs coins sableux et l'information stratigraphique issue de sites préhistoriques montre que ces différentes structures traduisent plusieurs d'extension méridionale du pergélisol pléistocène. L'interprétation de la signification paléoclimatiques des structures, sans être univoque, conduit à distinguer des épisodes de pergélisol continu/discontinu et/ou sporadique. L'hypothèse d'une récurrence de phases d'extension du Pergélisol européen pléistocène en réponse aux événements de Heinrich entre 32ka et 17ka est avancée.

International audience; Découverte en 1990, la grotte-abri de Peyrazet (Creysse, Lot, France) se situe dans le Haut-Quercy en bordure du causse de Martel, à quelques centaines de mètres du cours actuel de la Dordogne. Les fouilles menées depuis 2008 livrent une archéoséquence du Tardiglaciaire qui permet de combler certaines lacunes documentaires régionales et plus largement du Sud-Ouest de la France. Au Magdalénien supérieur succède un niveau ayant donné des indices d'un Azilien sensu lato stratigraphiquement séparé du Laborien, ensemble supérieur qui fait l'objet de cet article. Jusqu'alors ce technocomplexe de la fin du Pléistocène et des débuts de l'Holocène demeurait mal connu dans la région. En effet, seuls des travaux anciens menés dans deux gisements permettaient de noter sa présence en Quercy. La découverte d'un ensemble laborien récent (ou Épilaborien) à Peyrazet est l'occasion de conduire une étude collective des divers vestiges dans un cadre archéostratigraphique mieux maîtrisé. L'analyse géoarchéologique met en évidence l'action conjointe du ruissellement et de l'éboulisation comme principaux responsables de la mise en place des dépôts. Dans la partie SO du site, un lithofaciès de remaniement indique une bioturbation importante en lien avec le creusement de terriers. Bien que leur origine ne soit pas liée aux activités humaines, les rongeurs, les oiseaux, les poissons et les mésomammifères (excepté le lièvre) apportent des données concernant l'environnement des chasseurs-cueilleurs. La grande faune est dominée par le cerf dont les carcasses pourraient avoir été introduites incomplètes sur le site puis traitées pour en extraire la viande et la moelle. Nous avons bénéficié d'une analyse fonctionnelle croisée à l'étude typo-(a