A previously undocumented type of wetland is described from the Atacama Desert in northern Chile ... more 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 pale-osols 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.
Dune pattern, grain-size gradients and geochemistry were used to investigate the sources and dyna... more Dune pattern, grain-size gradients and geochemistry were used to investigate the sources and dynamics of aeolian deposition during the last glacial in southwest France. The coversands form widespread fields of low-amplitude ridges (zibars), whereas Younger Dryas parabolic dunes mainly concentrate in corridors and along rivers. Spatial modelling of grain-size gradients combined with geochemical analysis points to a genetic relationship between coversands and loess, the latter resulting primarily from dust produced by aeolian abrasion of the coversands. The alluvium of the Garonne river provided also significant amounts of dust at a more local scale. The geochemical composition of loess shows much lower scattering than that of coversands, due to stronger homogenisation during transport in the atmosphere. Overall, sandy loess and loess deposits decrease in thickness away from the coversands. Dune orientation and grain-size gradients suggest that the efficient winds blew respectively from the W to the NW during the glacial, and the W-SW during the Younger Dryas. A comparison between the wind directions derived from the proxy data and those provided by palaeoclimatic simulations suggests a change of the main transport season. Ground surface conditions and their evolution throughout the year, i.e. the length of the season with snow and frozen or moist topsoil, and the seasonal distribution of wind speeds able to cause deflation are thought to have been the main factors that controlled the transport season in the study area.
Le gisement de plein air de Mirande 2 a été récemment découvert sur la commune de Vaïssac (Tarn-e... more Le gisement de plein air de Mirande 2 a été récemment découvert sur la commune de Vaïssac (Tarn-et-Garonne), à une centaine de mètres du site de Mirande 1 fouillé entre 1971 et 1976 par R. Guicharnaud à Nègrepelisse. Cette opération de sondage préventif a permis d'évaluer les potentialités du site, d'en proposer une contextualisation géologique précise et d'exhumer les divers éléments de diagnose présentés ici. Mirande 2 est implanté sur un léger replat en rive gauche de l'Aveyron. Les trois secteurs de fouille (Tranchée Sud, Coupe Nord et Sondage) ont exclusivement livré des vestiges lithiques (silex et quartz) dont les caractéristiques typo-technologiques sont constantes d'une zone à l'autre et forment un ensemble cohérent sur le plan chronoculturel. Les premières observations archéostratigraphiques indiquent l'existence d'une concentration principale plus ou moins dilatée selon les secteurs. Les vestiges, dont les caractéristiques technotypologiques permettent d'attribuer l'ensemble au Badegoulien, se répartissent en différents types de supports et matières premières. Quelques blocs de trachyte façonnés et des galets de quartz débités proviennent vraisemblablement de la paléo-terrasse sur laquelle se sont installés les groupes humains. Les quartz sont présents sous la forme de macro-outils ou débités pour obtenir des éclats. L'essentiel des silex abandonnés sur le site provient des terrasses de la Vère et de l'Aveyron. Quelques indices tendraient également à montrer un apport de volumes en silex allochtones sur près de 100 km depuis le nord. En revanche, les autres matériaux allochtones sont présents sous la forme d'outils, signant vraisemblablement une fin de cycle fonctionnel. Du point de vue des supports d'outils à vocation domestique, on note une double composante. Des grattoirs, outils multiples et pièces à retouches latérales sont réalisés sur lame et éclats laminaires. Pour cette composante, et en l'état de l'analyse, l'hypothèse de deux schémas opératoires peut être proposée : une production laminaire cintrée et un débitage de supports envahissants sur face large. D'autres outils (racloirs, raclettes) sont réalisés sur éclats résultant de diverses chaînes opératoires parfois autonomes. Les microlithes sont composés de lamelles et micro-lamelles à dos de différents types et dont les supports sont produits à partir de rognons et éclats selon différentes modalités. Si le gisement de Mirande 2 constitue un nouveau témoignage d'occupations de plein air sur la paléo-terrasse de l'Aveyron, à proximité de sa confluence avec le Gouyré, il offre avant tout l'un des premiers jalons badegouliens entre Languedoc et Quercy, dans une région où il était peu connu jusqu'alors.
The Land Use and Cover Area frame Statistical survey (LUCAS) database on topsoil properties in Eu... more The Land Use and Cover Area frame Statistical survey (LUCAS) database on topsoil properties in Europe was used to map aeolian deposits. The points which satisfy the grain-size criteria of coversands, loess and transitional facies were extracted from the rasters of predicted soil texture established by kriging of the LUCAS data by Ballabio et al. (2016). A comparison with already available maps, derived from a conventional field approach, shows a good fit in most of the tested areas. The new map, however, suggests a greater extension of loess, which seems related to the inclusion of thin loess covers, usually omitted by conventional mapping, and the presence of previously unmapped areas due to lack of survey or misinterpretation. The main source of aeolian particles corresponds to glacio-fluvial sediments at the margin of the Scandinavian and Alpine ice sheets. Coversands and loess form a broad band across northern Europe, and in the Rh^ one, Rhine and Danube valleys. Large areas on the outskirts of these deposits also received a significant loess contribution, which has been reworked in slope deposits. Conversely, southern Europe is characterized by much less loess accumulation. The Atlantic coast has transgressive dune fields that penetrate inland to varying degrees.
La partie centre-ouest du Bassin aquitain est caractérisée par une vaste couverture sableuse, auj... more 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 inté-gré 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. Abstract: 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 chro-nostratigraphic analyses, demonstrating that the formation indeed involves an erg that began to form in the early Qua-ternary. During the Late Glacial, the Sable des Landes was already a large natural unit within the southwest of 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 to 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, doubtlessly 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
Detailed stratigraphic analysis and numerical dating (OSL, IRSL, ESR, 14C) of Pleistocene coversa... more 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.
Découverte en 1990, la grotte-abri de Peyrazet (Creysse, Lot, France) se situe dans le Haut-Querc... more 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 S-O 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
Detailed stratigraphic analysis and numerical dating (OSL, IRSL, ESR, 14C) of Pleistocene coversa... more 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 deposition.
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. Lateglacial
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 45N 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.
"The Shi’bat Dihya 1 site in western Yemen, dated by optically stimulated luminescence
to 55 ka,... more "The Shi’bat Dihya 1 site in western Yemen, dated by optically stimulated luminescence
to 55 ka, provides insight into the Middle Paleolithic peopling of
the Arabian Peninsula. The archaeological layer is interstratified within thick,
sandy silt floodplain deposits filling a piedmont basin. Luminescence dates, lack
of soil development, and gypsum precipitation indicate a high accretion rate of
the floodplain during Marine Isotope Stage 3, in connection with a (semi)-arid
environment. Rapid overbank sedimentation was likely a result of the remobilization
of loess material deposited on the Yemeni Great Escarpment at the
periphery of the adjacent Tihama coastal sand desert or of other sources. Fabric
and size analyses of the lithic artifacts, together with spatial projections, indicate
site modifications by floods. Primary modifications include (1) selective
accumulation of medium-sized lithic pieces as a result of hydraulic sorting, (2)
bimodal orientation of artifacts, and (3) ripple-like arrangement of lithics and
bone/tooth fragments. The overrepresentation of teeth may also be a consequence
of sorting. Although floods have distorted the original site patterning,
long-distance transport of artifacts by water can be excluded, as indicated by
relatively high refitting rate, close proximity of artifacts derived from the same
block of raw material, and lack of abrasion of the pieces. Therefore, the site is
considered “geologically” in situ because its remobilization by water occurred
shortly after human abandonment. This study also stresses that the effective
preservation of a site cannot be assessed without careful taphonomic study,
even in a potentially favorable depositional context such as silty alluvium."
The Shi'bat Dihya 1 site in western Yemen, dated by optically stimulated luminescence to 55 ka, p... more The Shi'bat Dihya 1 site in western Yemen, dated by optically stimulated luminescence to 55 ka, provides insight into the Middle Paleolithic peopling of the Arabian Peninsula. The archaeological layer is interstratified within thick, sandy silt floodplain deposits filling a piedmont basin. Luminescence dates, lack of soil development, and gypsum precipitation indicate a high accretion rate of the floodplain during Marine Isotope Stage 3, in connection with a (semi)-arid environment. Rapid overbank sedimentation was likely a result of the remobilization of loess material deposited on the Yemeni Great Escarpment at the periphery of the adjacent Tihama coastal sand desert or of other sources. Fabric and size analyses of the lithic artifacts, together with spatial projections, indicate site modifications by floods. Primary modifications include (1) selective accumulation of medium-sized lithic pieces as a result of hydraulic sorting, (2) bimodal orientation of artifacts, and (3) ripple-like arrangement of lithics and bone/tooth fragments. The overrepresentation of teeth may also be a consequence of sorting. Although floods have distorted the original site patterning, long-distance transport of artifacts by water can be excluded, as indicated by relatively high refitting rate, close proximity of artifacts derived from the same block of raw material, and lack of abrasion of the pieces. Therefore, the site is considered "geologically" in situ because its remobilization by water occurred shortly after human abandonment. This study also stresses that the effective preservation of a site cannot be assessed without careful taphonomic study, even in a potentially favorable depositional context such as silty alluvium. C
"The recovery at Shi’bat Dihya 1 (SD1) of a dense Middle Paleolithic human occupation dated to 55... more "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 Arabian Peninsula has long been considered as a region devoid of long-term human settlement ... more "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 duringMIS
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 lower terraces of the Dordogne River at Bergerac (south-west France) were studied in detail u... more The lower terraces of the Dordogne River at Bergerac (south-west France) were studied in detail using cores, trenches, ground penetrating radar profiles, and 14 C, optically stimulated luminescence and infrared stimulated luminescence dating. This study shows that the lowest terrace (Fx) is made up of two major lithostratigraphic units: (i) dominantly horizontal gravel strata interpreted as compound bar deposits in a braided river, which pre-date 18-17 ka, and (ii) thick lateral accretion gravel units (point bars) formed in an anabranching river during the Late Pleniglacial and Lateglacial. Most of the anabranching channels were abandoned at ca. 11-10 ka following shrinkage of the river bed into a single meandering channel and were partially filled by gyttjas during the Boreal chronozone. Finally, the channels were plugged by overbank fines until about 5 ka. Floods seldom reached the Fx terrace during the late Holocene and accretion became negligible. The main phase of bedrock incision spanned the Holocene, whereas the period of channel adjustment to change in river regime during late Marine Isotope Stage (MIS) 2 only led to a redistribution of the Pleniglacial gravels. The higher terrace (Fw3) formed before the Eemian and was covered by colluvial fans, mainly during MIS 2 and 3.
During the last glacial period, a large part of the Aquitaine basin (southwest France) was a peri... more 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 DeO 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 hunteregatherer 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 Périgord. 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.
The recovery at Shi'bat Dihya 1 (SD1) of a dense Middle Paleolithic human occupation dated to 55 ... more 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.
Geoarchaeology: an International Journal 27, 471-491 doi 10.1002/gea.21419
The Shi'bat Dihya 1 site in western Yemen, dated by optically stimulated luminescence to 55 ka, p... more The Shi'bat Dihya 1 site in western Yemen, dated by optically stimulated luminescence to 55 ka, provides insight into the Middle Paleolithic peopling of the Arabian Peninsula. The archaeological layer is interstratified within thick, sandy silt floodplain deposits filling a piedmont basin. Luminescence dates, lack of soil development, and gypsum precipitation indicate a high accretion rate of the floodplain during Marine Isotope Stage 3, in connection with a (semi)-arid environment. Rapid overbank sedimentation was likely a result of the remobilization of loess material deposited on the Yemeni Great Escarpment at the periphery of the adjacent Tihama coastal sand desert or of other sources. Fabric and size analyses of the lithic artifacts, together with spatial projections, indicate site modifications by floods. Primary modifications include (1) selective accumulation of medium-sized lithic pieces as a result of hydraulic sorting, (2) bimodal orientation of artifacts, and (3) ripple-like arrangement of lithics and bone/tooth fragments. The overrepresentation of teeth may also be a consequence of sorting. Although floods have distorted the original site patterning, long-distance transport of artifacts by water can be excluded, as indicated by relatively high refitting rate, close proximity of artifacts derived from the same block of raw material, and lack of abrasion of the pieces. Therefore, the site is considered "geologically" in situ because its remobilization by water occurred shortly after human abandonment. This study also stresses that the effective preservation of a site cannot be assessed without careful taphonomic study, even in a potentially favorable depositional context such as silty alluvium. C
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southwest France enable the construction of a renewed chronostratigraphic framework for sand deposition.
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. Lateglacial
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 45N 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.
to 55 ka, provides insight into the Middle Paleolithic peopling of
the Arabian Peninsula. The archaeological layer is interstratified within thick,
sandy silt floodplain deposits filling a piedmont basin. Luminescence dates, lack
of soil development, and gypsum precipitation indicate a high accretion rate of
the floodplain during Marine Isotope Stage 3, in connection with a (semi)-arid
environment. Rapid overbank sedimentation was likely a result of the remobilization
of loess material deposited on the Yemeni Great Escarpment at the
periphery of the adjacent Tihama coastal sand desert or of other sources. Fabric
and size analyses of the lithic artifacts, together with spatial projections, indicate
site modifications by floods. Primary modifications include (1) selective
accumulation of medium-sized lithic pieces as a result of hydraulic sorting, (2)
bimodal orientation of artifacts, and (3) ripple-like arrangement of lithics and
bone/tooth fragments. The overrepresentation of teeth may also be a consequence
of sorting. Although floods have distorted the original site patterning,
long-distance transport of artifacts by water can be excluded, as indicated by
relatively high refitting rate, close proximity of artifacts derived from the same
block of raw material, and lack of abrasion of the pieces. Therefore, the site is
considered “geologically” in situ because its remobilization by water occurred
shortly after human abandonment. This study also stresses that the effective
preservation of a site cannot be assessed without careful taphonomic study,
even in a potentially favorable depositional context such as silty alluvium."
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 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 duringMIS
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."