Age and date for early arrival of the Acheulian in Europe (Barranc de la Boella, la Canonja, Spain)

The first arrivals of hominin populations into Eurasia during the Early Pleistocene are currently considered to have occurred as short and poorly dated biological dispersions. Questions as to the tempo and mode of these early prehistoric settlements have given rise to debates concerning the taxonomic significance of the lithic assemblages, as trace fossils, and the geographical distribution of the technological traditions found in the Lower Palaeolithic record. Here, we report on the Barranc de la Boella site which has yielded a lithic assemblage dating to ,1 million years ago that includes large cutting tools (LCT). We argue that distinct technological traditions coexisted in the Iberian archaeological repertoires of the late Early Pleistocene age in a similar way to the earliest sub-Saharan African artefact assemblages. These differences between stone tool assemblages may be attributed to the different chronologies of hominin dispersal events. The archaeological record of Barranc de la Boella completes the geographical distribution of LCT assemblages across southern Eurasia during the EMPT (Early-Middle Pleistocene Transition, circa 942 to 641 kyr). Up to now, chronology of the earliest European LCT assemblages is based on the abundant Palaeolithic record found in terrace river sequences which have been dated to the end of the EMPT and later. However, the findings at Barranc de la Boella suggest that early LCT lithic assemblages appeared in the SW of Europe during earlier hominin dispersal episodes before the definitive colonization of temperate Eurasia took place.The research at Barranc de la Boella has been carried out with the financial support of the Spanish Ministerio de Economı´a y Competitividad (CGL2012- 36682; CGL2012-38358, CGL2012-38434-C03-03 and CGL2010-15326; MICINN project HAR2009-7223/HIST), Generalitat de Catalunya, AGAUR agence (projects 2014SGR-901; 2014SGR-899; 2009SGR-324, 2009PBR-0033 and 2009SGR-188) and Junta de Castilla y Leo´n BU1004A09. Financial support for Barranc de la Boella field work and archaeological excavations is provided by the Ajuntament de la Canonja and Departament de Cultura (Servei d’Arqueologia i Paleontologia) de la Generalitat de Catalunya. A. Carrancho’s research was funded by the International Excellence Programme, Reinforcement subprogramme of the Spanish Ministry of Education. I. Lozano-Ferna´ndez acknowledges the pre-doctoral grant from the Fundacio´n Atapuerca. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

The first Miocene fossils from coastal woodlands in the southern East African Rift

The Miocene was a key time in the evolution of African ecosystems witnessing the origin of the African apes and the isolation of eastern coastal forests through an expanding arid corridor. Until recently, however, Miocene sites from the southeastern regions of the continent were unknown. Here, we report the first Miocene fossil teeth from the shoulders of the Urema Rift in Gorongosa National Park, Mozambique. We provide the first 1) radiometric ages of the Mazamba Formation, 2) reconstructions of paleovegetation in the region based on pedogenic carbonates and fossil wood, and 3) descriptions of fossil teeth. Gorongosa is unique in the East African Rift in combining marine invertebrates, marine vertebrates, reptiles, terrestrial mammals, and fossil woods in coastal paleoenvironments. The Gorongosa fossil sites offer the first evidence of woodlands and forests on the coastal margins of southeastern Africa during the Miocene, and an exceptional assemblage of fossils including new species

Myélome et lymphome des personnes de plus de 75 ans ( traitement, évaluation fonctionnelle et sociale)

Propos - La prévalence des lymphomes et des myélomes augmente. L'âge avancé des patients et les comorbidités associées rendent complexe leur prise en charge. Cette étude a pour but de décrire cette prise en charge et l'évolution fonctionnelle et sociale de patients âgés de 75 ans et plus atteints de lymphome ou de myélome. Méthode - Etude rétrospective descriptive s'appuyant sur la lecture de 62 dossiers de patients suivis en court séjour de gériatrie et d'hôpital de jour de gériatrie et d'hématologie du centre hospitalier de Saint-Nazaire, entre 2002 et 2007. Les comorbidités, la fragilité, l'autonomie, le traitement, et le devenir des patients ont été étudiés. Résultats - 53,2% de patients atteints de myélome, et 46,7% de lymphome. 25 hommes et 37 femmes, dont l'âge moyen était de 82 ans (extrêmes 75-93 ans). 88,7% avec un Performance Status entre 0 et 2 au moment du diagnostic. 45,2% patients fragiles, 9,7% en institution, et 17,8% déments. Le suivi médian était de 17 mois (extrêmes 0-58 mois). Une chimiothérapie à doses standard fut proposée dans 33,9% des cas, et à doses adaptées dans 50% des cas. 17,8% des patients fragiles et 20,6% des non fragiles ont dû interrompre le traitement pour toxicité. Le traitement standard a apporté aux patients fragiles un bénéfice pour 50% d'entre eux, et une durée de vie sans symptôme de 6 mois. Pour les non fragiles, le bénéfice était de 93,3% et la durée de vie sans symptôme de 10 mois. Le niveau d'autonomie a baissé de 30,6% sur l'ensemble des dossiers. 17,7% de rémission, dont 83% de rechutes en moins de 6 mois. La mortalité était de 62,9%, dont 43,6% de décès précoces. Conclusion -Cette étude permet d'avancer que quelle que soit l'intensité du traitement, le bénéfice apporté est moins important pour les sujets fragiles que pour les non fragiles. Il n'y a cependant pas de différence concernant la tolérance du traitement, et le traitement standard semble être le plus approprié, pour les patients fragiles, et les non fragiles. Des études sur la tolérance des traitements et sur leur impact en terme de qualité de vie dans ces populations seraient une aide à la décision thérapeutique.NANTES-BU Médecine pharmacie (441092101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Quantification des processus superficiels et datation par les radionucléides cosmogéniques 10Be, 26Al et 36Cl

Produits dans l’environnement terrestre lors de réactions nucléaires entre les particules énergétiques issues du rayonnement cosmique et les atomes constitutifs de cet environnement, les radionucléides cosmogéniques à vie longue tels que le Béryllium-10 (10Be, T1/2 ~1,4 Ma), l’Aluminium-26 (26Al, T1/2 ~0,7 Ma) et le Chlore-36 (36Cl, T1/2 ~0,3 Ma) permettent, en utilisant la fraction produite dans l’atmosphère, d’étudier la variation de l’intensité des paramètres qui en contrôlent la production (activité solaire et champ géomagnétique) et de dater, sur des gammes temporelles couvrant les dix derniers millions d’années, les dépôts sédimentaires marins et continentaux dans lesquels ils s’accumulent avant de décroître. La fraction produite dans la croûte terrestre (production in situ), précisément mesurable depuis seulement une vingtaine d’années, permet de quantifier les processus d’érosion fonctionnels à la surface terrestre et de dater différents types d’archives sédimentaires sur la gamme temporelle 0,1-5 Ma. Afin de réaliser ces quantifications, une méthode spécifique capable de séparer le radionucléide cosmogénique d’intérêt de ses interférents massiques, au moins plusieurs millions de fois plus abondants, a dû être développée. Basée sur la caractérisation du nombre de masse (N) et du numéro atomique (Z), la technique de Spectrométrie de Masse par Accélérateur (SMA) appliquée aux géosciences a permis de reconstituer les variations d’intensité du champ magnétique terrestre au cours des derniers 1,3 millions d’années, de dater la couche fossilifère contenant le crâne de Sahelanthropus Tchadensis (Toumaï) et de préciser la chronologie de la dernière déglaciation dans différents contextes environnementaux.Produced in the terrestrial environment during nuclear reactions between energetic particles from the cosmic ray and the constituent atoms of the Earth’s environment, long-lived cosmogenic radionuclides such as Beryllium-10 (10Be, T1/2 ~1.4 Ma), Aluminium-26 (26Al, T1/2 ~0.7 Ma) and Chlorine-36(36Cl, T1/2 ~0.3 Ma) allow using the fraction produced in the atmosphere to study the intensity variations of parameters that control production (solar activity and geomagnetic field) and dating on temporal scales covering the last ten million years marine and continental sedimentary deposits in which they accumulate before decreasing. Fraction produced in the crust (in situ production) precisely measurable since only twenty years, allows measuring in specific mineral fractions accumulated amount that depends on both duration of exposure to cosmic radiation and the stability of the surface studied to quantify surface processes modeling the Earth's surface and dating different types of surface markers on the time range 0.1‑5 Ma. To achieve these quantifications, a specific method able to separate the cosmogenic radionuclide of interest from its mass interfering, at least several million times more abundant, had to be developed. Based on the unambiguous characterization of both the mass number (N) and atomic number (Z), the technique of Accelerator Mass Spectrometry (AMS) applied on geosciences including reconstruct variations in the intensity of Earth's magnetic field over the past 1.3 million years, to date the fossil layer containing the skull of Sahelanthropus tchadensis (Toumaï) and to clarify the chronology of the last deglaciation in different environmental contexts

Absolute dating of an Early Paleolithic site in Western Africa based on the radioactive decay of in situ-produced 10Be and 26Al

International audienceAlong the Angolan coast, the Early Paleolithic sites of Dungo IV and V (Baia Farta, Benguela) have delivered a rich pre-Acheulean lithic industry testifying the antiquity of the horninin settlement in western Africa despite the current absence of any hominin fossil in the area. In Dungo IV, the Paleolithic level is located on a conglomeratic paleo-beach (104 m a.s.l.) buried under an at least 3 m thick sandy layer. In Dungo V, two unearthed large whale fossils are associated with numerous lithic tools intimately mixed with the whale bones. This is the oldest evidence of stranded marine mammal scavenging by hominins in this part of Africa. The lack of volcanism and fossils makes chronological constrain difficult. Considering its configuration, the Dungo IV site may be relevant for a dating based on both the Be-10 and Al-26 cosmogenic nuclides. For this purpose, a depth profile all along the sandy layer overlying the archeological layer has been sampled. Statistical treatments performed on the Al-26/Be-10 PU/Be ratios obtained for the depth profile demonstrate that they all belong to the same population. If we consider that the samples have always been at or close to their sampling depth, the regression modeling allows computing that the surface sedimentary layer has been emplaced at least 614 ka ago and less than 662 ka ago. On the other hand, if we consider that the surface deposit has been truncated, burial durations ranging from 585 ka to 786 ka and truncations lower than 4 m result from the modeling of the evolution of the Be-10 and Al-26 concentrations as a function of depth. The analyses of four pre-Acheulean artefacts lead to a minimum burial duration of 730 ka and a maximum burial duration of 2.11 Ma. The low pre-burial denudation rates modeled from the data acquired for the stone tools as well as for the overlying layer (1-16 m.Ma(-1)) imply large inherited Al-26 and Be-10 concentrations. The post-depositional maximum denudation rate of 71 m.Ma(-1) associated with both the lithic artefacts and the surface sedimentary layer (considering that the samples have always been at or close to their sampling depth) as well as the deduced maximum uplift rate of similar to 170 m.Ma(-1) are in agreement with the known tectonic evolution and the climatic variability of this area. This study confirms the antiquity of the hominin presence in western Africa more than 2000 km away from the closest old hominin fossil sites

Datations des séries sédimentaires à hominidés anciens du paléolac Tchad depuis le miocène jusqu'à l'actuel

Deux méthodes de datations ont été adaptées pour contraindre les âges des restes d hominidés découverts dans les sédiments mio-pliocènes du bassin du Tchad. La thermochronologie des traces de fission, théoriquement applicable vue la forte proportion d hydroxyapatite cristallisée formant les os et dents, a donné des résultats médiocres en raison de leurs structures internes et d une certaine mobilité de l U dans les fossiles au cours de l enfouissement, trop complexes pour permettre une datation des fossiles du Tchad par l analyse des traces de fission. En revanche, la datation basée sur le nucléide cosmogénique 10Be atmosphérique normalisé par son isotope stable 9Be a été testée pour la première fois en contexte continental et avec succès sur la phase authigène des sédiments du Tchad. Ainsi, l âge d Australopithecus bahrelghazali, le premier australopithèque découvert 2500 km à l ouest du Rift Est Africain est estimé à 3,6+-0,3 Ma, résultat en accord avec le degré évolutif des assemblages de mammifères fossiles associés. De même, l utilisation du nucléide cosmogénique 10Be a permis de dater de manière quasi continue l unité sédimentaire à Anthracothères de la zone fossilifère de Toros-Ménalla en concordance avec la biochronologie et de contraindre l âge de Sahelanthropus tchadensis entre 6,9 et 7,2 Ma. En démontrant que le rapport 10Be/9Be authigénique peut être utilisé, dans des conditions spécifiques, comme un outil de datation absolue de dépôts sédimentaires continentaux contenant des restes d hominidés entre 0,2 et ~7 Ma, cette étude peut avoir un impact fondamental sur les domaines de recherche visant à préciser l évolution humaine et à calibrer l horloge moléculaire.Two dating methods were adapted to constrain ages of the hominid remains unearthed in Chadian basin Mio-Pliocene sediments. Fission track thermochronology, theoretically applicable considering the high proportion of crystallized apatite forming the bones and teeth, provides poor results due to the internal structures of the substrates and U exchanges during burial, which are generally too complex to allow fission track analysis dating of the Chadian fossils. For the first time, dating based on the atmospheric cosmogenic nuclide 10Be normalized to the dissolved fraction of its stable isotope 9Be was successfully tested in a continental context on the authigenic phase of Chadian sedimentary deposits. The age of Australopithecus bahrelghazali, the first Australopithecine unearthed 2,500 km west of the Rift Valley, is thus estimated at 3.6+-0.3 Ma, in strong agreement with the evolutive degree of the associated mammal assemblage. Also in strong agreement with the biochronology, the cosmogenic nuclide 10Be allows to quasi-continuously date the Anthracotheriid sedimentary unit in which Toumaï (Sahelanthropus tchadensis) was unearthed in the Toros-Ménalla fossiliferous area and then constrains the Sahelanthropus tchadensis age between 6.9 and 7.2 Ma. By demonstrating that authigenic 10Be/9Be ratio may be used, in specific conditions, as a dating tool of continental sedimentary deposits over the time period 0.2 to ~7 Ma, this study may have fundamental implications on important field research such as the hominid evolution and new calibration for the molecular clocPOITIERS-BU Sciences (861942102) / SudocSudocFranceF

10Be ages reveal > 12 ka of gravitational movement in a major sackung of the Western Alps (France)

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Evidence for Earlier Stone Age ‘coastal use’: The site of Dungo IV, Benguela Province, Angola

International audienceThe relationship between Earlier Stone Age (ESA) hominins and the southern African coastal environment has been poorly investigated, despite the high concentration of openair sites in marine and fluvial terraces of the coastal plain from c. 1Ma onward during the Mid-Pleistocene Transition. Southern Africa provides some of the earliest evidence of coastal subsistence strategies since the end of the Middle Pleistocene, during the Middle Stone Age (MSA). These coastal MSA sites showcase the role of coastal environments in the emergence and development of modern human behaviors. Given the high prevalence of coastal ESA sites throughout the region, we seek to question the relationship between hominins and coastal landscapes much earlier in time. In this regard, the +100 m raised beaches of the Benguela Province, Angola, are key areas as they are well-preserved and contain a dense record of prehistoric occupation from the beginning of the Middle Pleistocene, including sites like Dungo, Mormolo, Sombreiro, Macaca and Punta das Vacas. Accordingly, this paper provides a critical review of the coastal ESA record of southern Africa and a detailed presentation of the Dungo IV site, through a qualitative technological analysis coupled with a quantitative inter-site comparison with contemporary southern African coastal plain sites. Through our detailed technological analyses, we highlight the influence of coastal lithological resources on the technical behaviors of hominin groups, and we propose the existence of a "regional adaptive strategy" in a coastal landscape more than 600 000 years ago. Finally, we argue for the integration of coastal landscapes into hominins' territories, suggesting that adaptation to coastal environments is actually a slower process which begins with "territorialization" well before the emergence and development of Homo sapiens

Preliminary dating of the Mansu-Ri and Wondang-Jangnamgyo Early Paleolithic sites

International audienceThe lack of carbonates and fossils in Early Paleolithic open air river terrace sites in Korea makes chronological assessment difficult. Nevertheless, a paleomagnetic study of the thickest section (about 9 m) at Mansu-Ri (Locality IV) revealed only normal polarity, indicating an age younger than 0.78 Ma all along the section. In Mansu-Ri (Loc. IV), measurements of the in situ-produced Be-10 and Al-26 concentrations in two pebbles yield similar Al-26/Be-10 burial durations ranging from a minimum duration of 225 ka to a maximum duration of 621 ka. In Wondang-Jangnamgyo, two pebbles yield different Al-26/Be-10 burial durations with a minimum duration of 235 ka and a maximum duration of 495 ka for one and ranging from 975 ka to 3.2 Ma for the other. This last unrealistically old burial duration range most likely results from a complex history of successive burials and expositions. Interestingly, by analogy with the Chinese loess section, the obtained minimum burial durations are coherent with the paleomagnetism result interpretation associating to glacial cycles the 3 paleosoils covering the samples dated at Mansu-R