A. Benito-Calvo, A.I. Ortega, M. Navazo, D. Moreno, A. Pérez-González, J.M. Parés, J.M. Bermúdez de Castro & E. Carbonell
Boletín Geológico y Minero, 129 (1), 59-82.

The Arlanzón river is located in the NE Duero Depression (Castilian Plateau of northern Spain), where it drains the anticlinal ridge of the Sierra de Atapuerca, where a rich record of karstic and open air Palaeolithic archaeological sites are located, spanning the last 1.22 Ma. The geomorphological sequence of this valley is composed of fourteen fluvial terraces from T1 (+92-100 m), to level T14 (+2-3 m), ranging from the Early Pleistocene to the Holocene and mainly related to cold MIS. Available chronological data and terrace relative heights extracted from LiDAR data, have allowed the reconstruction of the downcutting phases of the valley, which show an acceleration of the incision rates throughout the Quaternary, probably related to tectonic uplift. In the Sierra de Atapuerca multilevel endokarst system, three sub-horizontal cave levels appear spatially and chronologically related to the Arlanzón fluvial terraces T2 (+82-91 m), T3 (+70-78 m) and T4 (+60-67 m)/T5 (+50-58 m). The association between fluvial terrace base levels and sub-horizontal phreatic caves suggests a relatively short period of time for the formation of these phreatic passages when compared to karstic vadose entrenchments related to the low incision rates of the Arlanzón river (<0.038-0.045 m/ka). In the valley, the incision of 0.061 m/ka caused the progressive exhumation of a neogene limestone layer containing flint, which erosion and successive re-sedimentation phases by alluvial and colluvial processes on the valley slopes during the Middle and Upper Pleistocene caused many wide captation areas of raw material, which were exploited by the Neanderthals during MIS 3 and 4.

J.M. Parés, C. Álvarez, M. Sier, D. Moreno, M. Duval, J.D. Woodhead, A.I. Ortega, I. Campaña, J. Rosell, J.M. Bermúdez de Castro & E. Carbonell
Quaternary Science Reviews, 186, 1-16

The so-called “Gran Dolina site” (Atapuerca mountain range, N Spain) is a karstic cavity filled by sediments during the Pleistocene, some of which contain a rich ensemble of archaeological and paleontological records. These sediments have contributed significantly to our understanding of early human dispersal in Europe but, in contrast, older, interior facies deposits have received much less of attention. The stratigraphy of Gran Dolina reveals an abrupt sedimentary change of interior to entrance facies from bottom to top, reflecting a significant paleoenvironmental change that promoted the accumulation of sediments transported from the vicinity of the cave by water or “en masse”. Since the major magnetic polarity reversal known as the Matuyama-Brunhes boundary (0.78 Ma) was detected within the TD7 unit in the middle of the stratigraphic section, we carried out a new combined paleomagnetic, radiometric (U-Pb), and electron spin resonance (ESR) dating study of the lower part of the sequence in order to constrain the chronology of the interior facies at Gran Dolina. U-Pb analysis of speleothems did not produce age information as the samples proved to be extremely unradiogenic. The magnetic stratigraphy of the cave interior sediments reveals a dominant reverse magnetic polarity, coherent with a Matuyama age, and interrupted by a normal polarity magnetozone interpreted as the Jaramillo Subchron (1.0-1.1 Ma). ESR ages on quartz grains from the upper part of the interior facies sediments are coherent with such an interpretation. We conclude that the fluvial deposits (interior facies) that constitute the cave floor began accumulating before 1.2 Ma. The development of large cave entrances at Gran Dolina occurred shortly after the Jaramillo Subchron but before ca 900 ka ago.

Moreno, D., Richard, M., Bahain, J.J., Duval, M., Falguères, C., Tissoux, H. & Voinchet, P.
Quaternaire, 28 (2), 161-166

Electron Spin Resonance (ESR) applied to optically bleached quartz grains extracted from sediment provides an age estimate for the last exposure of sediment to sunlight. This method has been increasingly used in archaeological, geological and geomorphological contexts for the last 30 years. However, its successful application is highly dependent on the geological context and the type and quality of the material sampled. Therefore, appropriate sampling strategy and conditions are crucial to ensure reliable ESR ages. The aim of this paper is to provide basic background information on the best way to collect samples and select the most suitable materials for ESR dating. It is nevertheless highly recommended to contact an ESR geochronologist prior to fieldwork sampling.

Richard, M., Moreno, D., Bahain, J.J., Duval, M., & Falguères, C.
Quaternaire, 28 (2), 155-159

Unlike radiometric methods based on the measurement of radioactive growth or decay of isotopes (e.g., 14C, 40Ar/39Ar, 230Th/234U), the application of radiation exposure dating methods (OSL, TL, ESR) requires the acquisition of data from the sample itself, in addition to those related with its surrounding environment. Indeed, for Electron Spin Resonance (ESR) dating of tooth enamel, the origin of the sample as well as its sedimentary context must be well known to ensure an accurate dose rate reconstruction. The systematic record of sampling data in the field appears to be essential for the implementation of the method and thus the calculation of reliable age results. Consequently, we propose here some basic guidelines to help non-dating specialists intending to collect fossil teeth from archaeological or geological context for subsequent ESR dating purposes.

Duval, M., Bahain, J.J., Bartz, M., Falguères, C., Guilarte, V., Moreno, D., Tissoux, H., del Val, M., Voinchet, P. & Arnold, J.L.
Ancient TL, 35 (1), 11-19

More than 30 years after the first Electron Spin Resonance (ESR) dating application to optically bleached quartz grains by Yokoyama et al. (1985), the absence of standardization for reporting methodology and age results remains an obstacle for the development and recognition of the ESR dating method within the Quaternary scientific community. To overcome this issue, the present work proposes some basic guidelines which should hopefully be useful not only for the ESR dating community, but also for any potential reviewers who may not be familiar with the specificities of this field.

Despriée, J., Voinchet, P.,  Courcimault, G., Bahain, J.J., Puaud, S., Moreno, D., Chantreau, Y.,  Tissoux, H.,  Gallet, X., Chapon Sao, C., Abdessadok, S.  & Falguères, C.
Quaternaire 28 (1), 31- 48

Upstream of Vierzon city, the fossil fluvial system of the Cher River is composed of seven sandy alluvial formations, which include four stepped sheets deposited on the western slope of the valley and three formations stacked in the fault trough where the river is currently flowing. According to the available geochronological data (ESR on optically bleached quartz), these formations were deposited between 1 Ma and 60 ka. The Acheulian site of la Noira (Brinay, Cher) is located on the western slope, at the bottom of one of the terraces, “Les Fougères Formation”. At la Noira, the lowest Unit a, close to the valley side, is covered by the alluvial les Fougères Formation and could correspond to the beginning of a glacial stage. Hominins collected there lacustrine millstone slabs embedded in soliflucted coarse deposits lying on the substrate (Unit a). The slab fragments they broke were shaped into handaxes or knapped to produce large flakes. Subsequently, Unit a and the associated workshops were overlain by colluvium, then partly cryoturbated before being overlapped by the thick fluvial sands of the les Fougères Formation. This 6 m-thick formation at la Noira, is composed by a succession of three sand units (Units b, c, d) with unconformities covered by slope deposits or underlined by cryoturbation features and ice wedge pseudomorphs. According to ESR dates (mean weighted age: 665 ± 55 ka), deposition took place during the beginning of MIS 16.

Despriée, J., Courcimault, G., Voinchet, P., Puaud, S., Bahain, J.J., Moreno, D., Moncel, M.H., Gallet, X., Chantreau, Y.,  Tissoux, H. & Falguères, C.
Quaternaire 28 (1), 49-71

In the middle Cher river valley (Centre-Val de Loire Region, France) fieldworks and researches allowed a geological, geo chronological and paleoenvironnemental framework for the fluvial system and associated prehistoric sites. At Brinay (Cher department), the sandy alluvia of the Les Fougères Formation that overlap the Acheulian Site of la Noira was dated par ESR Method of 665 ± 55 ka. On this site, archaeological studies and excavations shown that hominins had prospected amounts of various weathered raw materials downsloping from the interfluve (Sub-Unit a1 / Unit a). Their strategy of supply seems to have consisted in several series of selections for gathering millstone slabs, while eliminating those which were previously alterated or frozen. These slabs were broken and the fragments were used for knapping flakes or shaping handaxes. During excavations, because of their freshness, evidence of primary position of these artifacts was observed. So, hominins were partially presents near by the river owing to reach raw materials. These in demand millstones are lacustrine silicifications that were uncovered during incision phase of the Cher river then sloped down in debris flows. These phenomena were resulting from climatic cyclicity and correspond to a transition phase at the beginning of a glacial stage and before pleniglacial stage (MIS 16) while the uncovered areas of Unit a and substratum were cryoturbated. In some valleys of the Middle Loire river Basin, others prehistoric assemblages were founded on the top of incision floors uncovered during different climatic cycles of the Early or Middle Pleistocene. Hominins activities on the alluvial plain food during the transition phase at the beginning of a glacial phase would be recurred cycle after cycle, but would be intermittent.

Moreno, D., Benito-Calvo, A., Falguères, C., Voinchet, P. & Pérez-González, A.
Actas de la XIV Reunión Nacional de Geomorfología (Málaga, España), 391-398

Knowledge of geomorphological evolution of fluvial networks in the Iberian Peninsula has considerably improved during recent years. However, the establishment of a chronological framework for these fluvial systems based on numerical data still remains a key issue. Dating methods which may be used on these sedimentary formations are limited because of lack of volcanic sediments and the old age of these deposits themselves. Electron Spin Resonance (ESR) applied on quartz grains extracted from sediments is a paleodosimetric method suitable for dating these fluvial sediments and for the whole Quaternary period. In their NE sector, the Duero Basin has two important tributaries: Arlanzón and Arlanza rivers. These valleys are conditioned by alpine tectonic structures, rise at the Sierra de la Demanda (Iberian Range) and flow through similar deposits (Paleozoic and Mesozoic rocks, continental tertiary deposits). A regional correlation model based on geomorphological characteristics between both river valleys was elaborated. In this work, we have applied for the first time the ESR method on quartz grains extracted from sediments on several fluvial terraces of the Arlanza river. We present these first ESR results as long as a preliminary correlation between the Arlanza and the Arlanzón valley for which ESR data are already available.

Antoine, P., Moncel, M.H., Limondin-Lozouet, N., Locht, J.L., Bahain, J.J., Moreno, D., Voinchet, P., Auguste, P., Stoetzel, E., Dabkowski, J., Bello, S.M., Parfitt, S.A., Tombret, O. & Hardy, B.
Quaternary Science Reviews, 149, 338 – 371

Dating the earliest human occupations in Western Europe and reconstructing links with climatic and environmental constraints is a central issue in Quaternary studies. Amongst the discovery of Palaeolithic artefacts ascribed to the Early Pleistocene in southeast Britain and central France the Somme Basin, where the Acheulean type-site Amiens Saint-Acheul is located, is a key area for addressing this topic. Research undertaken over the past 20 years on both Quaternary fluvial and loess sequences of this area has provided a unique dataset for the study of the relations between human occupations and environmental variations. Studies based on an interdisciplinary approach combining sedimentology, palaeontology and geochronology have highlighted the impact of the 100 kyrs cycles on terrace formation during the last million years. In this terrace system, the earliest in situ Acheulean settlements known in the 1990s were dated to early MIS 12 (±450 ka), but new field discoveries, at Amiens “Rue du Manege”, dated to ± 550 ka, significantly increase the age of the oldest human occupation in the area. In this context, new fieldwork has been undertaken in Abbeville at the Carriere Carpentier site, famous for its White Marl deposit attributed to the Cromerian and in the same terrace level where the former discoveries of “Abbevillian bifaces” were made by d’Ault du Mesnil. This research is based on an interdisciplinary approach, combining sedimentology, paleontology, dating (ESR on quartz and ESR/U-series on teeth) and archaeology. According to the various bio-proxies (molluscs, large vertebrates, small mammals), the White Marl was deposited during the early part of an interglacial phase in an aquatic slowflowing environment, as emphasized by the development of oncoliths and the presence of fish and aquatic molluscs. The landscape was composed of a mosaic of open bush and forest areas, in which wet and grassy vegetation developed on riverbanks. On the basis of terrace stratigraphy, ESR and ESR/Useries dating results, and biostratigraphic data, the fluvial deposits of the White Marl can be securely attributed to MIS 15. In addition, some Acheulean bifaces were discovered at the base of the slope deposits, directly overlying the fluvial sequence. These artefacts are most likely coeval with the end of MIS 15 or an early stage of MIS 14, between 550 and 500 ka, and represent, together with the artefacts from Amiens “Rue du Manege”, the oldest in situ evidence of Acheulean occupation in Northern France. However, no unquestionable artefacts have been discovered in the White Marl or in the underlying gravel layer. These discoveries contribute to the chronology of the earliest evidence of hominin occupations in north-western Europe which may be related to Homo heidelbergensis.

Despriée, J., Courcimault, G., Moncel, M.H., Voinchet, P., Tissoux, H., Puaud, S., Gallet, X.,   Bahain, J.J., Moreno, D. & Falguères, C.
Quaternary International, 411, 144 – 159

The Acheulean site of la Noira was fossilized beneath the Fougeres fluviatile formation dated by the ESR method at 655 ± 55 ka. Coarse deposits were left at the base after the end of the Cher incision and served as raw material deposits for hominins. The occupation level has yielded bifaces, cores and a flake assemblage in lacustrine millstone. The systematic recording of about 6 500 lithic objects brought to light the reasons underlying the presence of the diverse materials, and elucidated hominin choice of lacustrine millstone for knapping flakes and shaping bifacial pieces. The systematic study of all the materials enabled us to advance hypotheses concerning some of the behaviour identified at the site: sorting of raw materials affected by frost, cursory peripheral knapping of slabs of up to a metre long with hammers weighing several kilogrammes, breaking up of large slabs over 10 cm long and displacement of the fragments. This analysis assesses hominin behaviour and the management and exploitation of raw material deposits at 700 ka.

Moreno, D., Falguères, C., Pérez-González, A., Voinchet, P., Ghaleb, B., Despriée, J., Bahain, J.J., Sala, R., Carbonell, E., Bermúdez de Castro, J.M.,  Arsuaga, J.L.
Quaternary Geochronology, 30, 535 – 540

Ages based on independent methods, such as combined ESR-U series, luminescence, and magnetostratigraphic analyses have been obtained for the upper stratigraphical section of Gran Dolina site (TD6 to TD11 levels). However, the chronostratigraphical framework of this European Paleolithic key site remains incomplete because of its great antiquity and the lack of reliable methods. This paper provides new radiometric dates by electron spin resonance applied to optically bleached quartz grains for the whole stratigraphic sequence. The results agree with the previous chronostratigraphical framework for the upper part of the stratigraphical sequence. The ages for the Homo antecessor remains from TD6 layer range between 800 and 900 ka. The lowest layers attributed to endogenous sediments (TD1) could be contemporaneous with the Sima del Elefante TE9 human bearing layer dated to 1.2 Ma. The results suggest a human occupation of possibly more than 1 Ma at the Gran Dolina site. This study confirms moreover the potential of ESR dating method applied on quartz in karstic environment.

Voinchet, P., Moreno, D.,  Bahain, J.J., Tissoux, H., Tombret, O., Falguères, C., Moncel, M.H., Schreve, D., Candy, I., Antoine, P., Ashton, N., Beamish, M., Cliquet, D., Despriée, J., Lewis, S., Limondin-Lozouet, N., Locht, J.L., Parfitt, S. & Pope, M.
Journal of Quaternary Science, 30 (7), 610 – 622

Increasing evidence suggests that bifacial technology (Acheulian, Mode 2) arrived in Europe during the early Middle Pleistocene, i.e. significantly earlier than previously proposed. In northern France and Britain, much of the age attribution for these assemblages has been based on biostratigraphy and lithostratigraphy rather than absolute dates. This study presents a systematic application of electron spin resonance (ESR) dating of sedimentary quartz and ESR/U-series dating of fossil tooth enamel to key Acheulian sites of this area. Although the age estimates have large associated uncertainties, most of the derived dates are consistent with existing age estimates. The new chronologies and the problems associated with dating material of early Middle Pleistocene age are discussed. In Britain, the earliest archaeology (cores and flakes, Mode 1) is older than Marine Isotope Stage (MIS) 15, whereas localities containing Acheulian technologies span late MIS 15/MIS 13 through to MIS 9. A similar pattern is seen in northern France although age estimates from sites such as la Noira suggest the possible appearance of the Acheulian in central France as early as MIS 17. The dates presented here support the suggestion that the earliest Acheulian appeared in NW Europe during the early Middle Pleistocene, significantly after its appearance in the southern parts of the continent

Duval, M., Bahain, J.J., Falguères, C., García, J., Guilarte, V., Grün, R., Martínez, K., Moreno, D., Shao, Q. &  Voinchet, P.
Quaternary International, 389, 213 – 223

ESR dating was applied to fossil teeth and optically bleached quartz grain samples from two units of the sequence at Vallparadís (Barcelona, Spain): weighted mean ESR age estimates of 858 ± 87 ka and 849 ± 48 ka were obtained for EVT-7, which includes the archaeological level 10, and EVT-8, respectively. These results are in good agreement with the existing magneto-biostratigraphic framework that constrain these deposits between 780 and 990 ka, and indicate that Vallparadís EVT-7 has a chronology ery close to that of Atapuerca Gran Dolina TD-6 (Spain).

Voinchet, P., Toyoda, S., Falguères, C., Hernandez, M., Tissoux, H., Moreno, D. &  Bahain, J.J.
Quaternary Geochronology, 30, 506 – 512

Luminescence and ESR dating methods of quartz sediment are based on the natural resetting of the signal by light exposure (optical bleaching). When the bleaching is incomplete, a residual dose (DeR) is added to the post-depositional dose accumulated since the deposit and hence the age is overestimated. Insufficient bleaching is usually linked to the environment and conditions of transport/deposition of the quartz grains affecting the light exposure duration. Indeed, each transportation mode – fluvial, marine or aeolian – is associated to specific conditions of light exposure, depending mainly to the location of grains in the transport agent during the transport phase, the opacity of the transport environment and the velocity of the transport. The present study attempts to discriminate the modes of transport/deposition providing a satisfying reset of the ESR signals of quartz grains. For this purpose, we investigated bleaching rates and ESR residual doses of aluminum centers from “present-day” aeolian, fluvial and marine sediments sampled in various sedimentary environments. The bleaching efficiency evaluation in these different environments may help for a better understanding of the resetting phenomenon for quartz signals which represents presently the main difficulty for ESR dating. The results show that the residual doses are small enough to allow an ESR dating of the main part of the sediment transported in almost all the context examined in this study. The smallest residual doses are obtained from quartz grains within the range of 100e200 mm and transported in clear water. Some limits for the application of optically bleached quartz ESR dating appears nevertheless, mainly when the residual dose and the dose accumulated after the deposit are quite similar, i.e. for Upper Pleistocene samples.

J.L. Arsuaga, I. Martínez, L.J. Arnold, A. Aranburu, A. Gracia-Téllez, W.D. Sharp, R.M. Quam, C. Falguères, A. Pantoja-Pérez, J. Bischoff, E. Poza-Rey, J.M. Parés, J.M. Carretero, M. Demuro, C. Lorenzo, N. Sala, M. Martinón-Torres, N. García, A. Alcázar de Velasco, G. Cuenca-Bescós, A. Gómez-Olivencia, D. Moreno, A Pablos, C.C. Shen, L. Rodríguez, A.I Ortega, R. García, A. Bonmatí, J.M. Bermúdez De Castro & E. Carbonell
Science, 344 (6190), 1358 – 1362

Seventeen Middle Pleistocene crania from the Sima de los Huesos site (Atapuerca, Spain) are analyzed, including seven new specimens. This sample makes it possible to thoroughly characterize a Middle Pleistocene hominin paleodeme and to address hypotheses about the origin and evolution of the Neandertals. Using a variety of techniques, the hominin-bearing layer could be reassigned to a period around 430,000 years ago. The sample shows a consistent morphological pattern with derived Neandertal features present in the face and anterior vault, many of which are related to the masticatory apparatus. This suggests that facial modification was the first step in the evolution of the Neandertal lineage, pointing to a mosaic pattern of evolution, with different anatomical and functional modules evolving at different rates