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

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

Dating results on sedimentary quartz, bones and teeth from the Middle Pleistocene archaeological site of Coudoulous I (Lot, SW France): A comparative study between TT-OSL and ESR/U-series methods.

International audienc

Testing the use of XAD resin to remove synthetic contamination from archaeological bone prior to radiocarbon dating

Museum collections are extremely valuable sources of material for ongoing research, although the conservation history of some objects is not always recorded, which can be problematic for chemical analyses. While most contamination is removed using the acid-base-acid treatment, this may not be the case for cross-linked contamination. The XAD resin protocol was implemented at the radiocarbon (14 C) laboratory in the Muséum national d'Histoire naturelle, and the setup was tested using known age bone samples and a consolidated Palaeolithic bone. Known age samples were consolidated with shellac or Paraloid, aged for a month, treated with or without the XAD resin and 14 C dated. Bone blank results showed that XAD resin was able to remove shellac, which was not the case for the ABA-only method. Results from VIRI I were more variable and VIRI F was possibly too young to show the effects of the consolidants. Two 14 C dates on the Palaeolithic bone after XAD treatment are statistically the same, while a sample without XAD treatment was significantly older, suggesting that the contaminant was not fully removed by the ABA-only treatment. This study demonstrates the potential of the XAD treatment to clean heritage bone samples stored in museums prior to geochemical analyses

New ESR/U-series dates in Yabrudian and Amudian layers at Qesem Cave, Israel

International audienc

ESR/U-series and ESR dating of several Middle Pleistocene Italian sites: Comparison with 40Ar/39Ar chronology

The stratigraphic sequences of numerous Palaeolithic sites of Central and Southern Italy, very rich in both archaeological and palaeontological remains, have also recorded Pleistocene volcanic events through volcanic ash deposits (tephra). They allow the establishment of an accurate chronological framework by comparing results obtained by 40Ar/39Ar dating method on single volcanic K-feldspar crystals, with those derived from ESR and ESR/U-series analyses on fluvial bleached quartz and tooth enamel respectively. Since 2009, these three methods were hence applied on samples of several Middle Pleistocene sites of Central and Southern Italy including both volcanic and archaeological levels (from the west to the east): La Polledrara di Cecanibbio, Isoletta, (Latium), Guado San Nicola, Isernia La Pineta (Molise), Valle Giumentina (Abruzzo) and Venosa Notarchirico (Basilicata). The obtained results, covering a time range from 660 to 350 ka, prove that such a multi-method approach when possible is essential to constrain the chronology of each site and allow the recognition of the specific limitations due to the lack of quartz for ESR or to complex geochemical histories in teeth rendering difficult the ESR/U-series method. Despite these limitations, the ESR framework is globally in agreement with the 40Ar/39Ar chronology, while ESR/U-series dates can be underestimated for the oldest sites. In such cases, an isochron approach attests however of the quite good reliability of the palaeodosimetric reconstruction and the observed age underestimation could be related to other factors affecting the ESR age determination

ESR/U-series dates on Equus teeth from the Middle Pleistocene Acheulean site of Cueva del Angel, Spain

International audienceThe Cueva del Angel (Lucena, Spain) is an open-air archaeological site with a sedimentary sequence remnant of a collapsed rock shelter which was part of a still active karst complex. The lithic assemblage consists essentially of abundant retouched tools including 46 identified handaxes along with non-modified flakes, and is associated with faunal remains dominated by Equus ferus and other large bovids and cervids. A large proportion of bones has undergone intense anthropic actions and been subjected to intense fire, thus evidencing sustained use of animal meat resources by humans. In order to better ascertain the chronological framework of the site, we dated several proxies. Various speleothem samples were processed by U-series using a coupled induced plasma mass spectrometer (ICPMS-MC). The resulting isotopic ratios are beyond the secular equilibrium and show that these samples do not appear to be in direct stratigraphic relation with the archaeological sequence. Nine Equus teeth were analysed by the combined ESR/U-series method. These samples were taken from Unit I to Unit XVI representing at least 2.5 meters of stratigraphic depth and approximately 90 % of the infilling. Many of the dated samples are burnt given that more than 85 % of the faunal remains exhibit traces of fire exposure

ESR/U-series dates on Equus teeth from the Middle Pleistocene Acheulean site of Cueva del Angel, Spain

International audienceThe Cueva del Angel (Lucena, Spain) is an open-air archaeological site with a sedimentary sequence remnant of a collapsed rock shelter which was part of a still active karst complex. The lithic assemblage consists essentially of abundant retouched tools including 46 identified handaxes along with non-modified flakes, and is associated with faunal remains dominated by Equus ferus and other large bovids and cervids. A large proportion of bones has undergone intense anthropic actions and been subjected to intense fire, thus evidencing sustained use of animal meat resources by humans. In order to better ascertain the chronological framework of the site, we dated several proxies. Various spe-leothem samples were processed by U-series using a coupled induced plasma mass spectrometer (ICPMS-MC). The resulting isotopic ratios are beyond the secular equilibrium and show that these samples do not appear to be in direct stratigraphic relation with the archaeological sequence. Nine Equus teeth were analyzed by the combined ESR/U-series method. These samples were taken from Unit I to Unit XVI representing at least 2.5 m of stratigraphic depth and approximately 90% of the infilling. Many of the dated samples are burnt given that more than 85% of the faunal remains exhibit traces of fire exposure. The bone retouchers, for which a comparative analysis with other sites has been published (Moigne et al., 2016), were probably produced during the Marine Isotope Stage (MIS 11-5) chronological interval corresponding to the later part of the Middle Pleistocene, inference that is in agreement with the palaeontological assemblage of the site. The radiometric results presented here are consistent and indicate a range from 350 to 183 ka, suggesting that a major part of the sedimentary infilling coinciding with the human occupation was contemporaneous with the MIS 9 to 7 time period

The first use of olives in Africa around 100,000 years ago

International audienceThe olive tree was an iconic plant for most of the past Mediterranean civilizations, for which it had important economic value. Here we report the earliest use of fruits and wood from olive trees in Africa so far, around 100,000 years ago. These findings suggest the presence of olive trees on the Atlantic coast of Morocco during most of the last glacial period, and the use of olives by the early Homo sapiens for fuel management and most probably for consumption

Des téphras piégés par le karst ardéchois : contexte et chronostratigraphie du remplissage de l’Aven du Devès de Reynaud (Saint-Remèze, Ardèche).

International audienc

Reconstruction of the MIS 5.5, 5.3 and 5.1 coastal terraces in Latium (central Italy): A re-evaluation of the sea-level history in the Mediterranean Sea during the last interglacial

We present a geomorphological, stratigraphical and geochronological study reconstructing a suite of paleosurfaces in a 200 km-long coastal sector of the central Tyrrhenian Sea between Argentario and Circeo promontories. Identification of the near-shore deposits associated with these paleo-surfaces allow us to define corresponding marine terraces and paleo sea-levels. Ar-40/Ar-39 and ESR/U-Th geochronologic constraints on key deposits provide correlation with the terraces previously recognized in the coast of central Latium, refining their correlation with the Marine Isotopic Stages. Results of this study enable us to:Propose a re-assessment of the ages for the sea-level markers of MIS 5.5, 5.3, 5.1 in the central Tyrrhenian Sea;Suggest that a continuous tectonic uplift with an average rate of 0.224 mm/yr affects the Latium coast since 200 ka;Provide new evidence for a MIS 5.5 paleo-sea level marker occurring at -35 m a.s.l. on the coastal sector extending from Montalto di Castro to Latina, while it possibly drops down and connects to a paleo sea-level ranging 10 - 5 m between Monte Circeo and Gaeta, previously attributed to this interglacial;Discussing possible evidence of similar elevation of the sea level during MIS 5.5, 5.3 and 5.1 interglacials in the Tyrrhenian Sea;Compare this datum with those from the western Pacific and several coral reefs, where the differences with respect to tectonically stable regions were attributed either to tectonics or to the Glacial Isostatic Adjustment, showing that the presented record of sea-level markers may have a strong impact on modeling the post-glacial effects in the Mediterranean Sea and on the paleoclimatic and paleoceanographic studies in this region