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ESR dating of quartz extracted from Quaternary and Neogene sediments: Method, potential and actual limits

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Abstract

ESR dating of fluvial, fluvio-marine and beach sediment has been tested using the Al centre in quartz grains from a basin and fossil beaches located around the Manche Channel. Dating was performed in conjunction with sedimentological, stratigraphical and neotectonical studies. The technical basis of the method is presented in the light of the study made on recent and fossil sediment in order to establish a procedure for the determination of the palaeodose. The application on a Neogene Basin samples allows to push back the dating ESR limits. Results show that ESR dating of sediment can provide chronozons which are necessary to the uderstanding of the history of a basin where classical chronological markers do not exist.

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... According to the faunal contents, following Jones and Keen (1993), it would rather be an estuary from the Waalian to Eburonian (1,5 to 1,4 Ma). It is possible that the Fart Beds could also be subsynchron of the lower Pleistocene of the Somme estuary, yielding 1,8 Ma (Mt Pillar, Laurent et al., 1998), here in a low stand facies. The Fart Beds could be the first testimony of the strait Quaternary closure at 1,79 Ma (Meijer & Preece, 1995). ...
... A similar situation prevailed during younger lowstands in the WA as Late Pliocene incisions (Gelasian) are truncated by such a surface close to the platform edge (Le Roy et al., submitted). To the South-West, the last major incision connected to this surface has been also dated on land to the base of the Tortonian by ESR (Laurent et al. 1998 ;Van Vliet-Lanoë et al., 2002;Van Vliet-Lanoë et al., 2009;Paquet et al., 2010). ...
... To the West, the last major incision has been also dated on land and on the near offshore to the base of the Tortonian by ESR (Electron Spin Resonance ; Laurent et al., 1998;Van Vliet-Lanoë et al., 2002Paquet et al., 2010). We had correlated the northern paleo-valley system responsible for the terraces described by Alduc, 1979 andAuffret et al., 1980, with the Late Miocene uplift of the Strait of Dover (Van Vliet-Lanoë et al., 2004) and the renewed opening of the strait during the Pliocene by capture of the Eastern Channel river net by the North Sea (differential subsidence). ...
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The Strait of Dover is possibly an element of the European rift, subsiding from the Paleoene to the Quaternary but mostly during the Oligocene extension phase resulting from the opening of the Northern Atlantic. But as it is superimposed on a zone in tectonic inversion, the tension could be limited in expression by the reactivation of the Variscan front. The inversion of the Variscan front accommodates most of the shortening induced by the Pyrenean Orogeny and the opening of the Northern Atlantic to the Western border of the European plate. The Boulonnais depression constitutes a marine gulf from the Ypresian, already excavated during the late Cretaceous. The re-analysis of the superficial sedimentary deposits inside the Boulonnais confirms a very early opening of the Strait of Dover, from the Eocene onward. The strait is open at the end of the Lutetian, during a part of the Oligocene and the late Mio-Pliocene, faunal assemblages of these two stages being identical on both sides of the strait. It is closed again from the early Quaternary for tectonic and eustatic reasons and re-open lately just prior to the Last Interglacial. These re-openings are related with the evolution of the Eastern Channel and its palaeo-valley system. Tectonic, geomorphologic and climatic implications of this dynamic are discussed within the Western European context. The inversion of the Strait of Dover region is practically synchronic with these of the basins of the Channel and North Sea areas and the strait may be interpreted from its functioning as an element of the European rift.
... The ESR method is particularly suitable when seeking to date whole systems of alluvial terraces, set up following the climate changes and tectonic movements that have occurred throughout the Quaternary. The systematic dating of this type of stepped terraces system, using always the same method and analytical protocol, permits to easily compare the results between them and thus to reconstruct the evolution of the valley over a long period (Laurent et al., 1998;Voinchet et al., 2010. ...
... Until recently, the dating by ESR of the lowest terrace levels of a fluvial system was considered not to be working properly. Indeed, the ages calculated for the lower terraces of several French fluvial systems were systematically overestimated and were rarely younger than 200 ka, in disagreement with the other available geochronological data (see for example in Laurent et al., 1998, Voinchet, 2002. For a long time, we explained that by the fact that these overestimated ages were due to the poor light sensitivity of aluminium (Al) center, used to determine the equivalent doses (D E ) and therefore ages. ...
... The dose rate was calculated from the radionuclide activities obtained by gamma-ray spectrometry measurements in situ (Inspector 1000, Canberra) using the threshold method of Mercier and Falguères (2007) and in our laboratory (Ortec low background germanium spectrometer). Age calculations were assessed using the doserate conversions factors from Adamiec and Aitken (1998), a k-value of 0.15±0.1 (Yokoyama et al., 1985;Laurent et al., 1998), α and β attenuation factors from Brennan (2003) and Brennan et al. (1991), water attenuation formulae from Grün (1994). The water content is measured by the difference in mass between the natural sample and the same sample dried for a week. ...
... Since the first ESR dating application to optically bleached quartz grains 16 , the alpha efficiency value has been systematically assumed (e.g. 4,[17][18][19][20]. Moreover, there have not been any detailed assessments of the potential age offsets that might arise from adopting assumed (or neglected) alpha dose rate components in ESR dating studies. ...
... This value has subsequently been adopted in several coarse-grained (60-200 µm) ESR dating studies (eg 17,18,20 ). Similarly, a k-value of 0.15 ± 0.1 has been assumed for fluvial and littoral sediments from France and Spain 4,19 . Although not specifically stated in 16 and 19 , we interpret both k-values proposed in the two studies as being equivalent to a-values of 0.17 ± 0.08 and 0.12 ± 0.08, respectively. ...
... This value is roughly half of the alpha efficiency value assumed (0.15-0.2, corresponding to 0.12-0.17 in the a-value system) in previous studies (e.g. 16,19 ). This value, though in the same order of magnitude, is higher than the alpha efficiency a-value measured in fine-grained quartz OSL studies (around 0.04; e.g. ...
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We present the first experimental evaluation of the alpha efficiency value for electron spin resonance (ESR) dating of coarse quartz grains, which is used for the evaluation of the internal and external alpha dose rate components. Based on our results, we recommend the use of an a-value of 0.07 ± 0.01 (1σ) for both the Al and Ti centres. Although we acknowledge that quartz ESR alpha efficiency may be sample dependent, and could also be impacted by other sources of uncertainty, this potential variability is presently impossible to evaluate given the absence of other experimental a-values available in the ESR dating literature. Measured radioactivity of quartz grains from the Moulouya catchment (NE Morocco) provides an internal dose rate in the range of 50–70 µGy/a when using an a-value of 0.07. The use of this empirically derived a-value for the evaluation of the internal and external alpha dose rate has a limited overall impact on the final ESR age results: they change by <2% and <3%, respectively, in comparison with those obtained with an assumed a-value. However, the large variability observed among the broader sample dataset for quartz internal radioactivity and hydrofluoric acid (HF) etching rates underscores the potential importance of undertaking experimental evaluations of alpha dose rate parameters for each dated sample.
... Al centers also support high doses of irradiation (Lin et al., 2006) without showing saturation effects, and therefore can be used to date old Quaternary samples (e.g. Laurent et al., 1998), since the Al center are stable for more than 10 6 years if the quartz samples are not heated (Toyoda and Ikeya, 1991). On the contrary, the Ti centers in some samples show a very weak signal and cannot be measured (which is the case in this study). ...
... This protocol was derived from that described in detail in the literature (Yokoyama et al., 1985;Laurent et al., 1994Laurent et al., , 1998Tanaka et al., 1997;Voinchet et al., 2003Voinchet et al., , 2004. ...
Article
The main objective of this study is to demonstrate that Electron Spin Resonance (ESR) dating of Quaternary sediments can be performed at Venezuelan Laboratory (Laboratorio de Física de la Materia Condensada – Instituto Venezolano de Investigaciones Científicas). The dating was carried out using quartz samples extracted from sedimentary Quaternary fill of three alluvial terraces (Qt12, Qt9 and Qt7) located along the Santo Domingo River (Mérida Andes, Western Venezuela), that have been previously studied and dated by Terrestrial Cosmogenic Isotope (¹⁰Be). The sedimentological characteristics of the Qt9 terrace fill indicate that the transport and sedimentation process of the sediments was under stable and high energy conditions. Our ESR dating suggest a maximum age of 85 ± 16 ka for this terrace, which is consistent with the ¹⁰Be ages previously published. In the case of the Qt12 and Qt7 terraces, field observations suggest a sediment transport process by debris flows, with rapid deposition. In this case, our ESR ages (228 ± 93 ka, 108 ± 33 ka, for Qt12 and Qt7, respectively) seem to be overestimated compared with the ¹⁰Be ages reported in previous studies. These results confirm that the sedimentary material to be used for dating through this technique must be deposited under stable conditions involving long-term sediment transport processes. This will allow the “optical bleaching” of paramagnetic centers to occur before the material is buried, as seems to have happened with the Qt9 terrace sample. The results discussed in this work support the existence of the technological and human resources necessary to carry out numerical dating of Quaternary sediments in Venezuela.
... Nomenclature of mammal species described from old collections were revised and updated by Auguste (1995aAuguste ( ,b,c, 2009 Former ESR dating results of 600 ± 90 ka (Laurent et al., 1994(Laurent et al., , 1998 led to the allocation of the White Marl to the end of the Cromerian Complex, in good agreement with the relative altitude of the alluvial formation in the Somme terrace system (Antoine, 1994) and with the interpretation of the large mammal assemblages from the White Marl. ...
... The combination of the whole set of ages obtained in the alluvial levels (including the date of Laurent et al., 1994Laurent et al., , 1998 (Fig. 7) provides a mean age of 584 ± 48 ka for the fluvial sequence of Carri ere Carpentier and suggests that the fluvial deposition of the White Marl was coeval to MIS 15. The mean age of the laminated yellow sands from the base of unit 3 (463 ± 51 ka) indicates that the sinkhole in which the sediment was sampled formed relatively quickly after the end of fluvial sedimentation. ...
... Electron spin resonance measurements have the advantage of selectivity over luminescence methods, by which is meant that the signal used for dating is representing the signature of one single paramagnetic defect. Al-hole ([AlO 4 /h] 0 ) signals in quartz have been extensively used for dating sediments (Duval et al., 2017;Duval and Guilarte, 2015;Laurent et al., 1998;Parés et al., 2018;Rink et al., 2007;Tissoux et al., 2008Tissoux et al., , 2012Tsukamoto et al., 2018;Voinchet et al., 2004Voinchet et al., , 2013Voinchet et al., , 2019. Assuming a first order formation process of this defect, one would expect the dose response curve to be well represented by a single saturating exponential function. ...
... Assuming a first order formation process of this defect, one would expect the dose response curve to be well represented by a single saturating exponential function. While in some studies a single saturating exponential function was used to fit the dose response curve of Al-hole ESR signal (Laurent et al., 1998;Rink et al., 2007;Tissoux et al., 2008;Tsukamoto et al., 2018), it was later shown that such a model fails to accurately represent experimental data, especially in the high dose range (Grün, 1991;Duval, 2012). For this reason, other analytical functions, such as single saturating exponential plus a linear function (Duval et al., 2017;Parés et al., 2018;Voinchet et al., 2004Voinchet et al., , 2019 or a sum of two saturating exponentials (Tissoux et al., 2012) have been suggested to fit the growth of the ESR intensity of Al-hole with accumulated dose. ...
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The mechanism governing the production of the paramagnetic [AlO4/h⁺]⁰ centres (denoted also as Al-hole or Al-h) in quartz as a function of given dose is of great importance in electron spin resonance (ESR) dating, as the analytical function used to characterise the evolution of this centre with accumulated dose is used to derive the equivalent dose by extrapolation to the abscissa-axis. The single saturating exponential model fails to accurately represent the dose response curve especially at high doses, and consequently, empirical functions, such as a saturating exponential plus a linear term, are widely used in the dating community. Herein, a physical phenomenological model is presented to describe the Al-hole formation under gamma irradiation in sedimentary quartz. Based on previous studies it is known that the Al-hole centre is formed via the dissociation of the Al centres compensated with alkali ions [AlO4/M⁺]⁰ (generally denoted as Al-M) where M⁺ could be Li⁺, Na⁺ or K⁺, as well as by the dissociation of Al compensated with hydrogen ions [AlO4/H⁺]⁰, (denoted as Al–H). When irradiation moves interstitial alkali ions away from the aluminium ions, they can be replaced by H⁺ ions beside the conversion to Al-hole centres. By assuming that the rate of the dissociation process is proportional to the concentration of the defects themselves, a sum of saturating exponential functions is obtained for describing the growth of Al-hole with dose. The model is applied on data obtained on sedimentary quartz specimens of different origins for describing the dose response of the paramagnetic Al-hole ESR signal. We are showing that the signal of Al-hole does not reach full saturation at doses even as high as 100 kGy and can it be well represented by two exponential components as predicted by the model. As such, the additional linear term reported by other works when describing the dose response is just a first order approximation of one of the saturating exponential functions.
... Optically stimulated luminescence (OSL) dating has become increasingly widely used in Quaternary research (Buylaert et al., 2007(Buylaert et al., , 2008; however, because of the restricted timeframe to which OSL can be applied (ca. the last 50,000 yr), in this study we used ESR dating. The ESR dating method is used to measure the last exposure age of deposits containing quartz, and can date samples that are hundreds to millions of years old, which is far beyond the 50,000-yr limit of OSL dating (e.g., Grün, 1989aGrün, , 1989bChen et al., 1991;Liang, 1993;Gao and Liang, 1995;Laurent et al., 1998;Liang and Gao, 1999;Blackwell et al., 2016). ...
... In practice, the natural accumulated dose is determined by exposing aliquots of the sample to artificial γ-radiation so that the specific ESR signal increases (Grün, 1989b;Liang, 1990Liang, , 1993Liu et al., 2011). In this way, the ESR method can be used to date sediments of up to 1 Ma in age (Laurent et al., 1998), and it has been widely employed (e.g., Li and Fang, 1999;Beerten et al., 2006;Beerten and Stesmans, 2007;Pan et al., 2007;Rink et al., 2007). ...
... Les nouveaux échantillons ont été datés en utilisant la méthode paléodosimétrique de la Résonance de Spin Electronique (ESR) appliquée aux quartz fluviatiles blanchis optiquement. L'application de cette méthode permet en théorie l'établissement de cadres chronologiques pour les dépôts littoraux (Gagnepain et al., 1998 ;Laurent et al., 1998) et fluviatiles (Laurent et al., 1994, 1998Voinchet, 2002 ;Bahain et al., 2007 ;Voinchet et al., , 2010Tissoux et al., 2011 ;Moreno et al., 2012 ;Duval et al., 2015). Ces dernières années, les études ont principalement porté sur ce dernier type de formations. ...
... La présence de ces impuretés permet la formation de centres-pièges paramagnétiques dont la capacité à retenir des électrons piégés (c-à-d. la durée de vie) est suffisamment grande à l'échelle des temps géologiques, de l'ordre de plusieurs centaines de millions d'années, pour permettre une utilisation géochronologique (Grün, 1989 ;Falguères et al., 1991 ;Ikeya, 1993 ;Laurent et al., 1998). La quantité d'électrons piégés est alors fonction de la dose totale de radiation reçue durant l'enfouissement. ...
Article
Since the 1990's, systematic dating of the alluvial deposits by the Electron Spin Resonance (ESR) method applied to optically bleached quartz had been undertaken in the Middle Creuse Valley (Indre department, France). Because of different substrata, the studied area had been divided into three sectors: the Massif Central, Intermediate and Parisian Basin sectors. The first data indicated that the stepped and embedded terraces of the fluvial system were deposited between 1.7 Ma and 130 ka, but it was difficult to correlate the results obtained in the three sectors, particularly for the Intermediate sector, where recent tectonics seems to have had a strong impact on the fluvial system geometry. In this sector which corresponds to the fault trough of Argenton-sur-Creuse, ten stepped or embedded fluvial formations (named I to X) had been described but only the lower sheets (I to VII) had been sampled and dated in previous works. Since 2000, systematic fieldworks have allowed the study of the higher formations (VIII, IX and X) and new samples were also taken in the middle-system sheets (V to VII). The results presented in this paper supplement the previous data, notably with the dating of some of the oldest alluvial sheets deposited in the Argenton-sur-Creuse fault trough. A better correlation with the upstream Massif Central sector is now possible and confirms the onset of the river incision during the Early Pléistocène and the evolution of the Creuse fluvial system all along the Middle Pléistocène.
... Les nouveaux échantillons ont été datés en utilisant la méthode paléodosimétrique de la Résonance de Spin Electronique (ESR) appliquée aux quartz fluviatiles blanchis optiquement. L'application de cette méthode permet en théorie l'établissement de cadres chronologiques pour les dépôts littoraux (Gagnepain et al., 1998 ;Laurent et al., 1998) et fluviatiles (Laurent et al., 1994, 1998Voinchet, 2002 ;Bahain et al., 2007 ;Voinchet et al., , 2010Tissoux et al., 2011 ;Moreno et al., 2012 ;Duval et al., 2015). Ces dernières années, les études ont principalement porté sur ce dernier type de formations. ...
... La présence de ces impuretés permet la formation de centres-pièges paramagnétiques dont la capacité à retenir des électrons piégés (c-à-d. la durée de vie) est suffisamment grande à l'échelle des temps géologiques, de l'ordre de plusieurs centaines de millions d'années, pour permettre une utilisation géochronologique (Grün, 1989 ;Falguères et al., 1991 ;Ikeya, 1993 ;Laurent et al., 1998). La quantité d'électrons piégés est alors fonction de la dose totale de radiation reçue durant l'enfouissement. ...
Article
Full-text available
Since the 1990’s, systematic dating of the alluvial deposits by the Electron Spin Resonance (ESR) method applied to optically bleached quartz had been undertaken in the Middle Creuse Valley (Indre department, France). Because of different substrata, the studied area had been divided into three sectors: the Massif Central, Intermediate and Parisian Basin sectors. The first data indicated that the stepped and embedded terraces of the fluvial system were deposited between 1.7 Ma and 130 ka, but it was difficult to correlate the results obtained in the three sectors, particularly for the Intermediate sector, where recent tectonics seems to have had a strong impact on the fluvial system geometry.In this sector which corresponds to the fault trough of Argenton-sur-Creuse, ten stepped or embedded fluvial formations (named I to X) had been described but only the lower sheets (I to VII) had been sampled and dated in previous works. Since 2000, systematic fieldworks have allowed the study of the higher formations (VIII, IX and X) and new samples were also taken in the middle-system sheets (V to VII).The results presented in this paper supplement the previous data, notably with the dating of some of the oldest alluvial sheets deposited in the Argenton-sur-Creuse fault trough. A better correlation with the upstream Massif Central sector is now possible and confirms the onset of the river incision during the Early Pleistocene and the evolution of the Creuse fluvial system all along the Middle Pleistocene.
... Nomenclature of mammal species described from old collections were revised and updated by Auguste (1995aAuguste ( ,b,c, 2009 Former ESR dating results of 600 ± 90 ka (Laurent et al., 1994(Laurent et al., , 1998 led to the allocation of the White Marl to the end of the Cromerian Complex, in good agreement with the relative altitude of the alluvial formation in the Somme terrace system (Antoine, 1994) and with the interpretation of the large mammal assemblages from the White Marl. ...
... The combination of the whole set of ages obtained in the alluvial levels (including the date of Laurent et al., 1994Laurent et al., , 1998 (Fig. 7) provides a mean age of 584 ± 48 ka for the fluvial sequence of Carri ere Carpentier and suggests that the fluvial deposition of the White Marl was coeval to MIS 15. The mean age of the laminated yellow sands from the base of unit 3 (463 ± 51 ka) indicates that the sinkhole in which the sediment was sampled formed relatively quickly after the end of fluvial sedimentation. ...
Article
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, palae-ontology 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 Man ege " , 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 Carri ere 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 interdis-ciplinary 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 slow-flowing 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 Quaternary Science Reviews 149 (2016) 338e371 and grassy vegetation developed on riverbanks. On the basis of terrace stratigraphy, ESR and ESR/U-series 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 Man ege " , 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 northwestern Europe which may be related to Homo heidelbergensis.
... The cited references normally explain the used dating techniques by site. Some of these dating techniques were pioneer attempts with correspondingly large error bars (e.g., ESR; Laurent et al., 1998). The TL and OSL ages greater than 100 ka likely underestimate the real ages. ...
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Van Vliet-Lanoë, B.; Andrieu, V.; Cliquet, D.; Authemayou, C.; Le Roy, P., and Renouf, J.C., 0000. Sea ice and the Middle to Recent Quaternary: Marine highstands in Western Europe. Journal of Coastal Research, 00(00), 000-000. Charlotte (North Carolina), ISSN 0749-0208. This study analyzes the raised beaches of less than 700 kilo annum (ka) above present sea level along the English Channel, which are associated with negative anomalies in d 18 O and evidence for anchor ice. The dated coastal events were compared in terms of recent storminess, sea-ice extents, and permafrost with regional paleoclimates. In western France, late Eemian and early interstadial highstands (HSs) indicate an extended annual sea-ice duration during early transgressions, with orbitally forced cold winters and a still-cool Southern Ocean. During regressions, storminess developed with a still-warm intertropical ocean but Arctic cooling. The Northern Atlantic ice sheets starved during early stadials, with aridity because of the seasonal sea-ice extent. (1) A delayed sea-level drop resulted from some ice storage in permafrost and sea ice, which caused depleted d 18 O seawater (d 18 Osw) values and limited ice caps. (2) The large ice sheets along the Northern Atlantic spread progressively and were delayed until marine isotope stage 4 (MIS 4). Their development resulted from summer precipitation rise caused by the cyclic restoration of thermohaline circulation during Dansgaard-Oechger (DO) events alternating with multiyear sea-ice cover. This led to a more unstable North Atlantic Current, which was repeatedly destabilized. (3) Early glacial storage partly or fully vanished during early DO or interstadial HSs, with climate conditions close to those of the present day. ADDITIONAL INDEX WORDS: Chronology, permafrost, storminess, ice sheets, marine d 18 O record, thermohaline circulation, topographic uplift.
... The dose rate was determined from radionuclide activities derived both from in situ and laboratory gamma-ray spectrometry measurements. The following parameters were used in the age calculation: dose-rate conversions factors (from Guérin et al., 2011); k-value of 0.15 ± 0.1 (Laurent et al., 1998); alpha and beta attenuations (from Brennan et al., 1991;Brennan, 2003); water attenuation formulae (from Grün, 1994); cosmic dose rate estimated from the Prescott and Hutton's (1994) equations. The internal dose rate was considered as negligible because of the low contents of radionuclides usually found in quartz grains (Murray and Roberts, 1997;Vandenberghe et al., 2008). ...
Article
In the Basilicata region, located in southern Italy and known for hosting among the first occurrences of the Acheulean culture in southwestern Europe, the Lower Paleolithic site of Loreto at Venosa is located less than a kilometer from the emblematic site of Notarchirico and less than 25 km from Cimitero di Atella. The Loreto site has not been studied as thoroughly as the two other sites and, although geological investigations have been carried out in the Venosa basin, no direct numerical dating has ever been published for the three archaeological levels brought to light during the excavation campaigns. We present a multi-method geochronological approach combining ESR/U-series, ESR, and ⁴⁰ Ar/ ³⁹ Ar permitting to refine the age of the most ancient archaeological level (A) of the Loreto site. These data allow us to propose an MIS 13 age for this level, in accordance with previous hypotheses based on geological and paleontological data. We also propose a technical review of the lithic tools preserved in the collection of the National Archaeological Museum of Venosa to integrate Loreto in the evolution scheme of the European Acheulean techno-complex emergence and diffusion.
... In this technique, the ali- quots of the sample are exposed to artificial γ-radiation, and therefore, the specific ESR signal increases (Grün, 1989). Thus, the ESR method can be used to date the deformation throughout the Cenozoic (Laurent et al., 1998;Liang and Gao, 1999;Li et al., 2013;Jia et al., 2018;Qiu et al., 2018). The other method is heat-activated ESR dating of quartz (Liang and Gao, 1999). ...
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The Cenozoic growth of the Tibetan Plateau and the distribution of deformation across it are a consequence of India-Asia collision and continued convergence, which have implications for studies of continental tectonics. The spatio-temporal development of Cenozoic deformation along the northern margin of the plateau is an important issue that can be better understood by testing various models of plateau growth. The northern Tibetan Plateau is bounded by the Cenozoic Qilian Shan thrust belt and the Haiyuan left-slip fault. We conducted geologic mapping, field observations, electron spin resonance (ESR) dating, and apatite (U-Th)/He (AHe) and apatite fission-track (AFT) analysis in the Qilian Shan thrust belt to improve our understanding of the timing of brittle faulting and range exhumation in the northern Tibetan Plateau. We document the first direct age constraints for Oligocene deformation within the central Qilian Shan via ESR dating, which correlates with AHe-AFT cooling ages in adjacent ranges. We demonstrate that the Qilian Shan thrust belt experienced a two-phase growth history, including Eocene−Oligocene fault-related uplift shortly after the India-Asia convergence, and mid-Miocene regional overprinting deformation that reactivated the proximal thrust faults. This deformational pattern suggests that the Qilian Shan thrust belt has experienced out-of-sequence development since the Eocene−Oligocene and has persisted as the stationary northeastern boundary of the Himalayan-Tibetan Orogen throughout the Cenozoic. The Paleozoic Qilian suture systems acted as a pre-existing weakness and played a decisive role in controlling the lithospheric rheology, which therefore impacted the timing, pattern, and strain distribution of Cenozoic deformation across the northern Tibetan Plateau.
... Irradiation at room temperature leads to the dissociation of [AlO 4 /M + ] 0 , resulting in the formation of [AlO 4 /H + ] 0 and [AlO 4 ] 0 [10]. [AlO 4 ] 0 , also referred to as Al-hole or Al-h, as a paramagnetic centre, is therefore detectable by EPR, and has been extensively used for dating sediments [6,7,9,[11][12][13][14][15][16][17][18][19]. Ti centres have also been widely used for dating [6,11,[18][19][20]. ...
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The possibility of EPR dating for sediments using Al-h signals of fine (4–11 μm) grains of quartz has not been previously discussed. Here, the Al-h and peroxy EPR spectra of fine (4–11 μm) and coarse (63–90, 125–180 μm) sedimentary quartz from thoroughly investigated loess sites in Eastern Europe were examined. By comparing experimental spectra with a simulated signal, we evaluated the overestimation observed when using the standard approach established by Toyoda and Falguères to measure Al-h intensity for different doses of radiation, up to 40,000 Gy. This overestimation, caused by the presence of peroxy signals, was much more pronounced for fine grains. Fine grains exhibited some additional dose-dependent signals, which, for some samples, caused a complete distortion of the Al-h spectra at high doses, making it impossible to measure the standard amplitude. We propose a new approach to measuring Al-h signal intensity, focusing on the peak-to-baseline amplitude of the part of the signal at g ≈ 2.0603, which is not affected by the peroxy signals and therefore has the potential of providing more accurate results. The shapes of dose response curves constructed for coarse and fine grains using the new approach show considerable similarity, suggesting that Al-h centre formation in fine and coarse grains upon artificial radiation at room temperature follows the same pattern.
... The electron spin resonance (ESR) dating method has been widely applied to different materials, including corals (Radtke and Grun, 1988;Ikeda et al., 1992;Schielein et al., 2020), fossil-tooth enamel, and bones (Gruen et al., 2010;Duval et al., 2017Duval et al., , 2020Ben Arous et al., 2019;Bahain et al., 2020), carbonates (Ikeya, 1975), mollusk shells (Molodkov, 2020), and quartz (Laurent et al., 1998;Liu et al., 2010Liu et al., , 2013Duval et al., , 2017Voinchet et al., 2020;Wei et al., 2020) of Pliocene to Late Pleistocene age. ESR dating can yield precise and accurate absolute ages and has thus become one of the main absolute dating methods for Quaternary geochronology. ...
Article
Multiple-centres electron spin resonance (MC-ESR) dating of quartz grains has been commonly applied to fluvial and lacustrine deposits and can provide a precise chronological framework for depositional histories. However, the reliability of this method for quartz grains obtained from sediments of boreholes, which are usually deposited continuously and record information regarding basin evolution and climate change, has not yet been assessed. In this study, we have initially applied the MC-ESR dating method to borehole sediments from the Zhoulao core (ZLC), located in the depocenter of the Jianghan Basin, middle Yangtze River, China. Dating of quartz grains from the ZLC using MC-ESR yields estimated ages that are generally consistent with the established paleomagnetic chronological framework. For Middle Pleistocene samples (i.e., 0.7–0.3 Ma), the Ti–Li centre provides more accurate ages than those of Al centre, which are overestimated. For Early Pleistocene samples (i.e., 2.3–0.8 Ma), both the Al centre and Ti–Li centre give highly consistent estimate ages, indicating that this is a favorable dating range for MC-ESR. Overall, the Al centre shows promise for dating Pliocene samples, whereas the Ti–Li centre is more suitable for Middle-Early Pleistocene (2.3–0.3 Ma) sediments. In addition, the deposition rate of depth <170 m in the ZLC is greater than those of depth >170 m sediments; however, the specific tectonic, climatic, or geomorphic mechanism for this change in sedimentation rate is still unclear.
... Although studies were done on dating fluvial sediments using ESR (e.g. Yokoyama et al., 1985;Laurent et al., 1998;Bahain et al., 2007;Tissoux et al., 2007Tissoux et al., , 2008Duval et al., , 2020Bartz et al., 2018;Voinchet et al., 2019;del Val et al., 2019), the potential effects of the residual signals before deposition in both the Al centre and Ti centre have not been well investigated. Voinchet et al. (2015) introduced a bleaching index for various fluvial and aeolian sediment samples, and a very small residual dose of 4-28 Gy, after subtracting the unbleachable signal of the Al centre, has been reported. ...
Article
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In this study, we examined the residual doses of the quartz electron spin resonance (ESR) signals from eight young fluvial sediments with known luminescence ages from the Lower Rhine terraces. The single aliquot regenerative (SAR) protocol was applied to obtain the residual doses for both the aluminium (Al) and titanium (Ti) impurity centres. We show that all of the fluvial samples carry a significant amount of residual dose with a mean value of 1270 ± 120 Gy for the Al centre (including the unbleachable signal component), 591 ± 53 Gy for the lithium-compensated Ti centre (Ti-Li), 170 ± 21 Gy for the hydrogen-compensated Ti centre (Ti-H) and 453 ± 42 Gy for the signal that originated from both the Ti-Li and Ti-H centres (termed Ti-mix). To test the accuracy of the ESR SAR protocol, a dose recovery test was conducted and this confirmed the validity of the Ti-Li and Ti-mix signal results. The Al centre shows a dose recovery ratio of 1.75 ± 0.18, whereas the Ti-H signal shows a ratio of 0.55 ± 0.17, suggesting that the rate of signal production per unit dose changed for these signals after the thermal annealing. Nevertheless, all fluvial sediments investigated in this study carry a significant residual dose. Our result suggests that more direct comparisons between luminescence and ESR equivalent doses should be carried out, and, if necessary, the subtraction of residual dose obtained from the difference is essential to obtain reliable ESR ages.
... External alpha, beta and gamma contributions were calculated from the radioelement contents (U, Th and K) measured in the sediment using a high resolution and low-background gamma-ray spectrometer and derived using the conversion factors of Gu erin et al. (2011). A k-value of 0.15 ± 0.1 (Yokoyama et al., 1985;Laurent et al., 1998) and a water content of 15% (wet weight%) were used for calculation. ...
Article
The middle Rhône valley, located at the southeastern margins of the Massif Central in France, produced a large number of Middle Palaeolithic sites, most of which dated to the Middle and Late Pleistocene. Due to its position, connecting northern Europe and the Mediterranean basin, this corridor and the surrounding plateaus are of particular interest in the study of human cultural evolution, including the emergence of Middle Palaeolithic technology around 300,000 years ago and its variability over time, as well as the subsistence and mobility strategies of Neanderthals. In the last 20 years, several research projects undertaken in this region allowed to revise key Middle Palaeolithic sequences. This work aims at synthesising previous and new chronological data obtained by using uranium-series of speleothems and bones, infrared stimulated luminescence of feldspar and electron spin resonance of tooth enamel and quartz. We review previous ages obtained in the area and present 43 new ages that are discussed together to propose a reliable spatiotemporal framework for Neanderthal occupations. We focus on major sites in the region: Payre, Ranc-Pointu 2, Baume Flandin, Abri du Maras, Grotte des Barasses II, Abri des Pêcheurs, Grotte du Figuier and Grotte de Saint-Marcel. They all provided significant information related to the biological and behavioural evolution of Neanderthal populations on the right bank of the Rhône valley. We present here the updated chronology for the Middle Palaeolithic of this area, ranging from ca. 300,000 to 40,000 years ago.
... The equivalent dose of a sample is proportional to the concentration of trapped electrons and so to its ESR intensity. The D e is determined using an additive protocol, which was described by Yokoyama et al. (1985) and modified first by Laurent et al. (1998) and later by Voinchet et al. (2004). The sample is divided into 10 to 15 aliquots artificially irradiated to different doses allowing the building of ESR intensity vs added doses growth curve. ...
Article
The Bytham River was one of the major pre-Anglian (MIS 12) rivers of eastern England. Flowing from the Midlands to the East Anglian coast, it has been recognised at numerous sites by its distinctive lithological suite, containing significant quantities of quartzite, quartz and Carboniferous chert that originate from central England. In the Breckland of Suffolk and Norfolk, deposits of the Bytham River can be identified at 26 sites by this distinctive clast lithological composition. These sediments, referred to as the Ingham Formation, consist of a series of sand and gravel aggradations, which due to their differences in elevation can be interpreted as at least four early Middle Pleistocene terrace remnants of the former river, and a final phase of deposition along the river valley prior to its destruction. This paper reports on recent fieldwork at six of these sites, which through stratigraphic and lithological analyses, together with new Electron Spin Resonance age estimates, contribute to a revised geological framework for the Bytham River as represented in the Breckland. These sites can be attributed to the four lowest fluvial aggradations, with the lowest and youngest of these aggradations shown to be early Anglian in age. The river was subsequently overrun by Anglian ice during Marine Isotope Stage 12. This revised geological and chronological interpretation provides an important framework for understanding the Lower Palaeolithic artefacts that have been found within these gravel aggradations, and contributes to the understanding of the human occupation of north-west Europe during the early Middle Pleistocene.
... Paramagnetic defects (i.e. that possess at least one unpaired electron) in sedimentary quartz are relevant for dating (Toyoda and Ikeya, 1991;Laurent et al., 1998;Toyoda, 2011). Thus, understanding the physical processes occurring in this mineral under different electronic excitations such as irradiation with ionising radiation or exposure to visible light (the resetting mechanism in sediment dating also known as bleaching) is of paramount importance. ...
Article
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E′ and Al-hole centres are some of the most common and abundant paramagnetic defects in sedimentary quartz. Here we investigate the dose dependence of these defects before and after exposure to light by electron spin resonance (ESR). Unlike the Al-hole centre, known to have only radiation-induced formation mechanisms, the E′ centre seems to possess a response to gamma dose characterised by predominantly radiation-induced annihilation at lower doses (up to about 1000 Gy) and a predominantly radiation-induced formation at higher doses, at least in the investigated dose range (up to 40 kGy) and samples. We propose these dose response mechanisms to be governed by electron trapping by E′ centre itself and by hole trapping by the oxygen deficiency centre (ODC), that seems to be the main precursor of E’ centre. We show that the ESR signals of both defects are linearly correlated during their formation as well as during their dissociation under both irradiation and sunlight exposure. The amount of E′ formed after light exposure was found to follow a saturating exponential behaviour as function of the annihilated Al-hole concentration in respect to dose, saturation being reached for doses of about 1000 Gy, probably due to the exhaustion of ODC population. As such, we propose that the origin of the unbleachable part of the Al-hole signal resides in the availability of oxygen deficiency centres which is also dependent on the accumulated gamma dose.
... Le corolaire est que le centre Al, blanchissant plus difficilement, sature également à de plus hautes doses d'irradiation. C'est la raison pour laquelle il peut être utilisé sur des gammes de temps plus grandes, pouvant atteindre plusieurs millions d'années (Laurent et al., 1998). Le centre Ti-H ne peut être utilisé que sur les échantillons supposés récents (Pléistocène moyen final et Pléistocène supérieur) (Miallier et al., 1994 ;Voinchet et al., 2020). ...
... OPTIQUEMENT BLANCHI Dans ce travail, la méthode utilisée pour connaître l'âge du dépôt des alluvions des diverses formations est celle de la résonance de spin électronique (ESR) appliquée aux grains de quartz fluviatiles blanchis optiquement (Yokoyama et al., 1985 ;Laurent et al., 1998 ;Voinchet et al., 2004 ;Tissoux et al., 2011 ;Moreno et al., 2012 ;Duval et al., 2015). ...
... Le corolaire est que le centre Al, blanchissant plus difficilement, sature également à de plus hautes doses d'irradiation. C'est la raison pour laquelle il peut être utilisé sur des gammes de temps plus grandes, pouvant atteindre plusieurs millions d'années (Laurent et al., 1998). Le centre Ti-H ne peut être utilisé que sur les échantillons supposés récents (Pléistocène moyen final et Pléistocène supérieur) (Miallier et al., 1994 ;Voinchet et al., 2020). ...
... Les (Laurent, 1993 ;Laurent et al., 1994Laurent et al., , 1998Voinchet et al., données inédites). Le centre Titane-Lithium semble pour sa part avoir été remis à zéro pour les échantillons issus du sondage 14 mais pas pour les sables du sondage 12, l'âge obtenu pour ces derniers par ce signal semblant fortement surestimé. ...
... Cependant les âges ESR/U-Th des dents issues des limons bruns, entre 120 et 150 ka, sont semble-t-il sous-estimés par rapport aux données géologiques et malacologiques disponibles pour ce niveau qui indiquent sa mise en place lors d'un interstadiaire ou d'un début de glaciaire. L'étude ESR des sables fluviatiles par une approche multi-centre a par ailleurs démontré un blanchiment insuffisant pour permettre d'utiliser le centre aluminium du quartz pour les quatre échantillons analysés, remettant également en question les données obtenues à Abbeville sur cette même nappe dans des travaux antérieurs (Laurent, 1993 ;Laurent et al., 1994Laurent et al., , 1998Voinchet et al., données inédites). Le centre Titane-Lithium semble pour sa part avoir été remis à zéro pour les échantillons issus du sondage 14 mais pas pour les sables du sondage 12, l'âge obtenu pour ces derniers par ce signal semblant fortement surestimé. ...
... Les travaux sur le Quaternaire de la Bretagne, associés aux recherches sur le Paléolithique, ont connu un essor important dans les années 1980 avec des travaux visant à définir les grandes formations de référence (Monnier et Morzadec-Kerfourn 1982, Bigot et Monnier 1987, Monnier et al. 2011), puis à préciser les processus pédosédimentaires et périgla- ciaires associés (Van Vliet-Lanoë 1988). Le dévelop- pement des datations TL (Loyer et al. 1995) puis ESR | La Préhistoire de la France 54et ESR/U-Th (Laurent et al. 1998, Van Vliet-Lanoë et al. 2000, Bahain et al. 2012) associé aux recherches les plus récentes (Laforge 2012) permet de mettre en parallèle la séquence régionale avec la stratigraphie isotopique marine (MIS)(fig. 5).MIS 13-12 : Les dépôts quaternaires les plus anciens sont reconnus dans le Cap Sizun (Finistère). ...
... Lors des mesures, on considère que la dose totale de radiations reçue depuis le dépôt correspond à la quantité d'électrons piégés stockée dans ces « chronomètres ». Il est ainsi possible, en déterminant cette dose totale (D e ) et en connaissant la dose annuelle (D a ) à laquelle est soumis l'échantillon, de calculer la durée du stockage, donc de dire à quel moment son « chronomètre » a été remis à zéro, c'est-à-dire quand il a été transporté puis déposé par la rivière (IKEYA, 1978(IKEYA, , 1993FALGUÈRES et al., 1985 ;GRÜN, 1989 ;LAURENT et al., 1998 ;VOINCHET, 2002 ;BAHAIN et al., 2007 ;TISSOUX et al., 2011 ;MORENO et al. 2012 ;DUVAL et al., 2015). ...
... Thermal stability constraints, however, place the upper age limit of ESR dating at around 1-2 Ma (Grün, 1989). ESR therefore does not give reliable age estimates for rocks formed before the Cenozoic (Laurent et al., 1998;Zhao et al., 2006). ...
Article
Sauropoda are the largest terrestrial animals to have ever lived and represent the dominant herbivorous dinosaurs of the Me-sozoic Era. The Lower Shaximiao Formation of the Sichuan Basin, Southwest China, hosts abundant Jurassic basal sauropods including the Shunosaurus-Omeisaurus Fauna. This formation was previously hypothesized to be Middle Jurassic based on biostratigraphic interpretations, but the exact depositional age is uncertain. Here we report the youngest inductively coupled plasma-mass spectrom-etry (ICP-MS) detrital zircon U-Pb age of 159 ± 2 Ma for fossil-bearing strata from this formation as the maximum depositional age. This age falls very close to the Oxfordian age interpreted for the Shunosaurus-Omeisaurus Fauna and is younger than previously proposed. We suggest that when the widely distributed basal sauropods of the Early-Middle Jurassic were mostly replaced by the phylo-genetically more-derived neosauropods in the Late Jurassic in other regions of Laurasia and Gondwana, some more basal members survived and diversified in the Sichuan Basin of southwestern China.
... Además, esta señal tiene un nivel de saturación con la dosis muy alta, por lo cual puede registrar dosis de varios miles de Gy (Duval, 2012), lo que puede permitir alcanzar periodos más antiguos que las señales OSL por ejemplo. Con una duración de vida promedia estimada a 7,4*10 9 años (Toyoda and Ikeya, 1991) este centro puede potencialmente ser utilizado para datar periodos muy antiguos, anteriores al inicio del Cuaternario (véase un ejemplo en Laurent et al., 1998). ...
Article
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ESR dating is a palaeodosimetric method based on the detection and quantification of the trapped charges accumulated over time in the crystal lattice of some materials due to their exposure to natural radioactivity. Like any chronometric dating methods, ESR has strengths and weaknesses. In particular, whilst the precision achieved with ESR is not as good as that of radiometric methods (e.g. radiocarbon, Ar-Ar or U-Th), it does have the advantage to being able to be used on a wide range of materials, covering thus almost any geological contexts during the last 2.6 Ma. Amongst them, the ESR dating of fossil tooth enamel and optically bleached sedimentary quartz grains are probably the most interesting applications in archaeology. This study mainly aims at showing an updated overview of the potential -and current limitations- of the ESR dating method used in geoarcheological contexts, through a synthesis of the previous studies carried out on various sites of the Iberian Peninsula that have been published over the last 30 years. © 2018, Instituto Geologico y Minero de Espana. All rights reserved.
... External alpha and beta contributions are calculated from the sediment radioelement contents (U, Th, and K) determined in laboratory by high resolution and low back ground gamma-spectrometry (Yokoyama and Nguyen, 1980). Age calculations are performed using the dose-rate conversions factors from Adamiec and Aitken (1998), a kvalue of 0,15 ± 0,1 (Yokoyama et al., 1985;Laurent et al., 1998), alpha and beta attenuations from Brennan (2003) and Brennan et al. (1991), water attenuation from Grün (1994), and a cosmic dose rate calculated from the equations of Prescott and Hutton (1994a,b). The internal dose rate was considered as negligible because of the low contents of radionuclides usually found in quartz grains (Murray and Roberts, 1997;Vandenbergue et al., 2008). ...
... 41.2-46.2 Ma was inferred by quartz electron spin resonance dating (Li et al., 2007), a technique usually performed on Quaternary sediments (Burdette et al., 2013;Duval et al., 2015) and the accuracy of which is generally considered as limited to the Pliocene (Laurent et al., 1998;Rink et al., 2007). Detrital-zircon chronostratigraphy represents a much more reliable approach for dating volcaniclastic sediments deposited within an arc-trench system including a magmatic arc, because they are likely to contain zircon grains as young, or almost as young as their depositional age (Amato and Pavlis, 2010;Kochelek et al., 2011;. ...
Article
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Sedimentary basins within the Transhimalayan arc-trench system provide paleotectonic and paleogeographic information on the evolution of the late Mesozoic-early Cenozoic Neo-Tethyan subduction zone along the southern Asian margin. This paper presents detailed stratigraphic, sedimentologic, petrographic, detrital-zircon geochronologic and Hf isotopic data from the Luogangcuo Formation exposed as part of the Xiukang Mélange in south Tibet. The Luogangcuo Formation was deposited (ca. 88-81 Ma) in a trench environment on a deep-sea fan fed from the Lhasa block through a submarine canyon. Dominant chert and subordinate sandstone and limestone clasts in conglomerate beds indicate recycling from the Neo-Tethyan subduction complex during repeated episodes of gravitational failure. The interbedded turbiditic sandstones were sourced directly from the Gangdese magmatic arc and central Lhasa terrane. Detrital volumes from the active Asian margin increased markedly at ca. 88 Ma as a result of uplift of central Lhasa, leading to deltaic progradation, filling of the Xigaze forearc basin, and bypassing of sediments funneled via canyons across the subduction complex to reach the Luogangcuo trench basin at abyssal depths.
... Depuis une vingtaine d'années, la méthode de datation par Résonance de Spin Électronique (ESR) appliquée aux quartz d'origine fluviatile a été développée dans le but d'établir la chronologie de dépôts alluviaux du Pléistocène (Aarab, 1994 ;Falguères et al., 2002 ;Laurent et al., 1994Laurent et al., , 1998Voinchet et al., 2003Voinchet et al., , 2004Tissoux et al., 2007Tissoux et al., , 2008. Elle a notamment été appliquée avec succès sur les systèmes de terrasses alluviales étagées ou emboîtées de plusieurs affluents de la Loire tels que le Loir, le Cher ou la Creuse (Voinchet et al., 2010 ;Tissoux et al., 2011). ...
... Cette intensité résiduelle doit donc être soustraite à l'intensité ESR de chaque aliquote pour pouvoir déterminer la dose de radiation reçue par l'échantillon depuis sa dernière exposition à la lumière, c'est-à-dire depuis son dépôt et son enfouissement (dose archéologique) (Fig. 2). C'est cette dose qui sera ensuite utilisée dans le calcul de l'âge de l'échantillon (Yokoyama et al., 1985 ;Laurent et al., 1998 ;Voinchet et al., 2004). ...
Article
Depuis le début des années 2000, des travaux portant sur la chronologie des premiers peuplements humains de Chine par les méthodes de la résonance de spin électronique (ESR) sur quartz sédimentaires et de la résonance de spin électronique couplée à l’uranium-thorium (ESR/U-Th) sur dents ont été menés en collaboration par des équipes françaises et chinoises sur quelques sites archéologiques ou géologiques chinois : Yunxian, Dali, Tangshan, Zongwei, Nihewan, Longgupo et plusieurs sites à giganthopithèques du Guangxi. Après une présentation rapide des méthodes de datation utilisées, quelques-uns des résultats majeurs obtenus dans le cadre de cette collaboration sont succinctement présentés et discutés.
... Although ESR dating of quartz has a great potential to extend the age range of sediment dating (e.g. Yokoyama et al., 1985;Laurent et al., 1998), it has not yet become a robust dating method. This is in sharp contrast to the luminescence dating methods which have been increasingly utilised in the last 15 years since the proposal of the single aliquot regenerative-dose (SAR) protocol (Murray and Wintle, 2000). ...
Article
Electron spin resonance (ESR) dating is a promising method for dating sedimentary quartz beyond a million years. Here we investigate the use of modern quartz samples with well bleached optically stimulated luminescence (OSL) signals to study the bleachability of the ESR signals, and to further check the applicability of the ESR single aliquot regenerative dose (SAR) protocol. The residual doses from five samples using both the Al- and Ti-centres were in general found to be large and, especially for the Al-centre, with a large variability. Although it is known that the Ti-centre is fully bleachable in nature, a subtraction of the residual dose using a modern analogue should be considered. Dose recovery tests were performed by using the single aliquot regenerative and added dose (SARA) method, and the dose recovery ratio (measured-to-added dose ratio) was obtained from the slope of the added vs. measured dose plot. The dose recovery ratio from the Ti-centre was satisfactory for all five samples indicating the validity of the proposed ESR SAR protocol. However, only one sample yielded a SARA plot for the Al-centre. This could be explained by the decrease in sensitivity caused by the annealing step in the SAR protocol and/or to the erroneous subtraction of the intensity of the peroxy centre, which overlaps with the Al-centre.
... Among them, ESR dating of fossil tooth enamel, sedimentary quartz grains, and speleothems are probably the most promising, since these materials are commonly found in association with archeologically significant remains. Early Pleistocene (e.g., Duval et al., 2012) Miocene (Al-center) (e.g., Laurent et al., 1998)~1 ...
Chapter
ESR dating is a paleodosimetric method based on the detection and quantification of the trapped charges accumulated over time in the crystal lattice of some materials due to their exposure to natural radioactivity. Perhaps more than any other chronometric method, ESR can be used in a very broad variety of archeological applications covering almost any geological context during the last 2.6 Ma. Among them, ESR dating of fossil tooth enamel, sedimentary quartz grains, and speleothems are probably the most promising, since these materials are commonly found in association with archeologically significant remains.
Article
In this paper we present a detailed Quaternary evolution model of the Seine valley (France). The lower Seine valley contains very specific preserved morphological features (semi-entrenched meander cut-offs) and develops in a karstified chalky plateau (Normandy Chalk). Regional geomorphological features make it possible to combine geomorphological observations, petrological investigations as well as cross-dating analysis of fluvial sediments and karstic archives. We have reviewed former chronological data through a combination of different dating methods including ESR, U-series as well as palaeomagnetism. We also present here new dating results from both cave deposits and fluvial terrace sediments through the combined use of quartz ESR dating method and palaeomagnetism. The obtained results show river evolution extending over the entire Quaternary period. The gentle incision rate and its variations highlight the influence of climate and eustatic processes, hence a partially climate-induced uplift. Results also provide new chronological markers on the fluvial deposits for future archaeological research.
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The evolution of the passive Armorican margin (Western France) during the Neogene and Quaternary was analyzed using field data. The morphology of the margin attests to a late Hercynian shaping, further deformation during the Mesozoic mid-Atlantic opening, during the Alpine Orogeny, and ultimately, a Late Cenozoic uplift, mostly related to an onshore isostatic accommodation in response to erosion and limited tectonic activity. A very limited strike–slip dynamic, with very low seismicity, accommodated the Neogene–Pleistocene N170 strains around the rigid Armorican terrane. The South Armorican domain and English Channel floor include shear zones that adjusted the Alpine convergence, facilitating its transpressive slip to the west. The Permo-Triassic N150 faults were reactivated during the inversion phases that began after the Bartonian under the distal control of the Alpine convergence and the decrease in the Atlantic spreading rate after 34 Ma. The Armorican marine platforms were stable after the late Eocene and slightly subsident, experiencing pulsed episodes of transient lithospheric doming during the Neogene and Quaternary. Co-seismic activity onshore without surface rupture was recorded around ∼5.3 Ma, ∼3.7 Ma, ∼2.4–1.2 Ma, and ∼400–250 ka, in tandem with an inland exhumation driven by isostatic adjustment due to an intensification of periglacial erosion at the onset of the early interstadials or by agriculture. Low-magnitude and ubiquitous shallow seismic activities seem to be related today to an isostatic uplifted old brittle–ductile transition due to the accumulation of shearing strain.
Article
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L’Acheuléen et la technologie de façonnage bifacial qui lui est associée sont, en Europe occidentale, caractéristiques des assemblages lithiques du Pléistocène moyen, période comprise entre environ 780 000 et 130 000 ans pour laquelle l’obtention d’âges numériques a longtemps été difficile. Depuis le début des années 1980, grâce au développement des méthodes paléodosimétriques de la résonance de spin électronique (ESR) ou de l’ESR combinée à la méthode uranium-thorium (ESR/U-Th), souvent les seules à pouvoir être appliquées sur des gisements aussi anciens, la chronologie de certains gisements de cette période a pu être précisée. En contexte alluvial notamment, l’application de ces méthodes aux sédiments formant les sites ou aux restes paléontologiques qu’ils contiennent a permis d’établir une chronologie de l’apparition et de la diffusion de cette technologie en Europe. Après une présentation rapide des méthodes utilisées, quelques résultats obtenus ces dernières années sur plusieurs sites acheuléens marquants d’Europe occidentale sont présentés.
Article
Résumé La révision des nappes alluviales de la Basse Somme intègre dans un même canevas deux séries de points d’observations complémentaires. La première série, proche des graviers de base regroupe les données de V. Commont et de A. Briquet. La seconde série de points appartient pour l'essentiel aux hautes et très hautes nappes, cartographiées par les auteurs dans les années 1980 . Cette distribution conduit à reconnaître un ensemble de 10 nappes principales et de 2 nappes complémentaires, s’inscrivant dans le prolongement des nappes du secteur d’Abbeville. La nappe supérieure étant rapportée à Jaramillo, on dispose donc d’un enregistrement régional complexe mais cohérent, réparti sur environ un million d’années, dont la signature paléoenvironnementale de haute résolution s’accorde avec celles de la séquence isotopique marine ODP 677 et des loess de Chine. Cet enregistrement intègre également l’assemblage laminaire dit de Croix-l’Abbé, situant celui-ci dans la partie médiane de SIM-8, vers 250 ka.
Article
Electron spin resonance dating is based on the principle that natural radiation creates paramagnetic defects in minerals. The method has been applied to various minerals starting from calcite of speleothems. As quartz is one of the most common minerals on the surface of the Earth, many applications are available on various geological events occurring on the Earth. The present review article summarizes the recent research results and directions of electron spin resonance dating of quartz.
Article
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 350 to 660 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.
Article
The geological sequences of numerous Lower and Middle Palaeolithic sites of central and southern Italy, found in fluvio-lacustrine contexts and rich both in archaeological and palaeontological remains, have recorded various volcanic events all along the Middle Pleistocene timescale. These sedimentary sequences made of detritic and volcanic materials are suitable to compare independent numerical geochronological methods and thus develop a multi-method approach relying especially ESR method applied to optically bleached fluvial quartz and the ⁴⁰Ar/³⁹Ar on single grain isotopic method applied to potassium feldspars. In this present paper, geochronological data obtained using these two methods were used on several Middle Pleistocene Italian sites including volcanic and fluvial but also archaeological levels: Isoletta and Lademagne in Lazio and Notarchirico in Basilicata. In this contribution, ESR age estimates were performed using a multi-centre approach from Al, Ti-Li and Ti-H centres. We demonstrate for these sites that ESR-based framework is overall consistent with the ⁴⁰Ar/³⁹Ar chronology that over the 700 and 350 ka time window. This comparison validates the multi-centre approach proposed and demonstrates that the use of Ti-H for samples with equivalent doses higher than 280-300 Gy leads to systematic age underestimates.
Article
The Cenozoic basins of western Iberia have a culminant allostratigraphic unit (designated UBS13), which records the beginning of Atlantic drainage and predates the fluvial incision that led to the development of the present drainage networks. However, the available numerical dating is quite limited and mainly restricted to the lower level terrace deposits. Therefore, this study uses for the first time the electron spin resonance (ESR) method to date this culminant unit in the Mondego and Lower Tejo Cenozoic basins of Portugal. The depositional age of this unit is supposed to lie between ~3.7 Ma (basal deposits) and ~1.8 Ma (uppermost deposits). The Al-centre provided reliable ESR data, but the dates obtained by using the Ti-Li centre clearly underestimate the burial ages. With reference to the existing independent dating of the Vale Farpado site (3.7–3.6 Ma) at the lowermost basal level of the UBS13 deposits, the ESR (Al-centre) ages of 3.0 to 2.3 Ma obtained for the UBS13 basal and middle deposits give reliable estimates of the burial age. The ESR ages (Al-centre) obtained for the UBS13 uppermost deposits indicate a probable age of ~1.8 Ma. Thus, these results are of international significance, in that they constitutes the first numerical ages obtained for the uppermost levels of the Cenozoic basin-fills of western Iberia, which predate the fluvial incision that took place in response to lower Quaternary base levels.
Article
The reliability of quartz electron spin resonance (ESR) dating using the Ti centre was tested through a comparison of the ESR ages of loess from the Luochuan site, Chinese loess plateau, with reference ages. Instead of the commonly used multiple-aliquot additive dose (MAAD) protocol, the single-aliquot regenerative dose (SAR) protocol was used to calculate the equivalent dose (De) values of five samples, with expected ages ranging from 28.5 ± 2.9 ka (unit L1) to 646 ± 65 ka (unit L6). The apparent ages, ranging from 59.4 ± 3.8 to 517 ± 42 ka, were then corrected for thermal signal loss, using the lifetime of the Ti centre, ∼1.7×10^6 years, previously calculated for a sample from the same site. The corrected ages ranged from 60.4 ± 3.8 ka to 617 ± 50 ka. For the youngest two samples both apparent and corrected ages overestimated the expected ages, which was presumably caused by incomplete signal resetting before burial. The apparent age of the oldest sample showed an age underestimation of ∼20%, but after the thermal signal loss from the Ti centre was corrected for, the age was consistent with the reference age. Both apparent and corrected ages of L3 and L4 are in good agreement with expected ages. We show, that with careful consideration of the thermal stability and bleachability of samples, reliable age calculation using the Ti centre is possible.
Article
Tourville-la-Rivière (Normandy, France) is one of the rare Middle Pleistocene palaeoanthropological localities of Northern France. Electron Spin Resonance (ESR) and combined ESR/U-series dating methods were independently applied by different teams on sediments and teeth from this site. The present work provides an overview of this multi-laboratory dating work by integrating a description and discussion of the methodologies employed and results obtained. Results confirm that the ESR/U-series analyses of the teeth are greatly dependent on the U-uptake histories of the dental tissues. Although all teeth come from the same archeological level, the samples analysed by each team display two different patterns for the U-series data. This is most likely related to the different sampling areas selected by each team and may be interpreted as the result of local variations in the geochemical conditions of the surrounding environment. Concerning the ESR dating of optically bleached quartz grains, the use of the multiple centre approach seems crucial when dating such fluvial and fluvio-lacustrine sediments. Our results also confirm the great potential of the Ti-H centre to date late Middle Pleistocene deposits. Despite some (expected) discrepancies related to the independent use of parameters and approaches by the different teams involved in this multi-laboratory study, the whole ESR and ESR/U-series data set collected from Tourville-la-Rivière locality consistently correlates stratigraphic levels D1 to I and associated human occupation to MIS7.
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A change in the constants used in K-Ar dating and a significant increase in new data have made a recompilation and recomputation of data used to define the Late Cenozoic K-Ar polarity time scale highly desirable at this time. All available data in the range 0-5 m.y. have been recalculated using the refined constants, with 354 data points in this time interval now meeting the minimum criteria for acceptability. Recalculation of the major polarity epoch boundaries has yielded ages of 0.73 m.y. for the Brunhes-Matuyama, 2.48 m.y. for the Matuyama-Gauss, and 3.40 m.y. for the Gauss-Gilbert boundaries. A revised polarity time scale has been constructed based on available K-Ar data and information obtained from marine magnetic anomalies and deep-sea sedimentary cores.
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A very precise dosimetry of a field of artificial irradiation is essential to estimate an accurate ESR Equivalent Dose (ED) in archaeology and geology. Archaeological powder samples and one sample of DL-alanine powder as control were prepared by IPH. Some alanine dosimeters of LMRI, constituted of L-alanine pellets, were joined to the IPH samples and together, irradiated in boxes using panoramic 60Co source under different experimental conditions. The LMRI had in charge the control of the process of irradiation and the measurement of each absorbed dose and dose rate delivered to the different series of boxes. This study consists in the evaluation of the distribution of dose on the samples. The ESR measurements made by the two laboratories were analysed and then compared. These experiments showed a significant gradient in the absorbed dose delivered to each LMRI dosimeter. The dispersion in each box was easily observable. However, a good agreement between the dosimeters and the alanine powder was observed in a same box.
Article
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ESR dates obtained at Menez-Dregan 1 (Brittany, France) focus interest on this Lower Palaeolithic site and demonstrate that the preserved anthropic combustion structures are among the oldest known in the world. It allows the dating not only of the little known "Colombanian Group" (it is an "archaic" original group characterized by many choppers and very few handaxes, différent from the Acheulian), but also, for the first time, of the old beaches on the southern coast of Brittany. Preserved bone remains are also very infrequent in Palaeolithic sites of Western France. The dating of the palaeolithic layer at the top of the third fossil beach can be connected with isotopic stage 11 or the beginningof isotopic stage 10; it shows that the âge of the geological and archaeological layers of Menez-Dregan 1 is probably between 350,000 and 500,000 years
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L'étude géochronologique des terrasses fluviatiles quaternaires du bassin de la Somme a permis de confirmer la chronostratigraphie précédemment établie sur les basses et moyennes terrasses et de placer les hautes terrasses dans la chronologie du Quaternaire.
Article
Geochronological study made on Quaternary fluvial terraces of Somme Basin confirmed the previously established chronostratigraphy of the lower and middle terraces and placed the higher terraces in the Quaternary stratigraphy. There is an abridged English version. -English summary
Article
The lower valley of the Somme river (northern France) contains a succession of interglacial deposits--fluviomarine sands, littoral bands, alteration zones, tuffs, periglacial deposits, loess, and coarse fluviatile alluvium--which can be correlated with the glaciations of the French Alps. The deposits range from pre-Guenz to post-Wuerm and are identified by their flora and fauna and the remains of prehistoric industries. Cross-sections illustrate the positions of the levels discussed.
Article
EnglishOne of the gravel sheets of the alluvial complex of the "Basse Somme" shows some characteristics which are considered as witness of a marine influence. This gravel sheet, named Croix l'Abbe Formation was deposited about a height of 25 m during a cold climatic episode of the Lower Pleistocene ; relationships with the terraces of the Somme between Pinchefalise and Saigneville are discussed here. One of the writters (De H.) describes the associated Palaeolithic artefacts. francaisUne des nappes du complexe alluvial de la Basse Somme presente des caracteristiques qui sont interpretees comme temoignant d'une influence marine. Cette nappe, decrite ici sous le nom de Formation de Croix l'Abbe, s'est mise en place vers 25 m d'altitude au cours d'un episode froid du Pleistocene inferieur ; ses relations avec les nappes alluviales de la Somme entre Pinchefalise et Saigneville sont discutees. L'un des auteurs (De H.) caracterise l'industrie paleolithique associee.
Article
Some ESR signals in quartz are reported to be bleachable by sunlight and so they promise to be useful for dating sediments (Grün, 1989). The Ge signal in quartz is the only one that shows bleaching effects with UV light in short time scales (hours). Therefore we used quartz samples from the sites of Mauer (‘Homo erectus heidelbergensis’), samples from a borehole in the Neckar valley (‘Entensee’, Ladenburg near Heidelberg) and samples from a pegmatite for basic studies on the Ge signal.The results show that with our standard sample preparation procedure for quartz separation (using red light as for TL samples), the natural Ge signal is not detectable, but rises clearly with gamma irradiation. Several experiments for examination of the stability and sensitivity of the Ge centre in quartz were carried out.For comparison with the behaviour of the Ge signal we measured the Al signal as well. Our experiments show that the Al signal is bleachable in long time scales (weeks). The behaviour on bleaching, irradiation and thermal annealing is very complicated, as the Al centre is a hole centre (it possibly interacts with several electron centres in the quartz and so the processes are of higher order).
Article
The behaviour of ESR signals due to titanium and aluminium centres in quartz sand on exposure to sunlight has been investigated. Samples of sand were recovered from cores taken off the coast of southeast Australia, at Forster-Tuncurry, and at an inland lake, Lake George. Naturally irradiated samples, and also samples which were annealed and then artificially irradiated with gamma rays, were used. The ESR signal due to titanium centres shows promise for dating the last exposure to sunlight of quartz grains.
Article
The determination of the “clock zero” is the key as to whether sedimentary rock can be used for estimation of ages by ESR (Wintle and Huntley, 1979). This paper reports preliminary results revealing that the intensity of the E′ center signal of quartz in sedimentary loess increased with exposure to sunlight. Hence it is impossible to establish the clock zero using bleaching by light.
Article
The age of a volcanic rock has been determined by ESR dating using the Ge center in quartz. The total dose of natural radiation and the age obtained from the Ge center are 460 krad and 2.07 ± 0.50 Ma, respectively, and those from the unidentified defect at g = 2.011 are 484 krad and 2.16 ± 0.21 Ma, respectively. These dates agree well with the age of 2.0 ± 0.5 Ma determined by the fission-track method. High stress or temperature destroy these accumulated defects but, in the same time, produce a lot of new diamagnetic precursors which enable us to observe the clear ESR signal.
Article
A comprehensive review (ca. 230 references) is presented of the present (1983) state of knowledge of paramagnetic defects in crystalline quartz, as derived from electron paramagnetic resonance spectroscopy and related techniques. An auxiliary description of relevant concepts in solid state electron paramagnetic resonance (EPR), suitable for the non-specialist, is included. The centres described include those arising from impurity ions (Al, H, Cu, Ag, Ge, P, Ti, Fe) as well as those (E) associated with oxygen ions missing in the quartz structure. Emphasis is placed on the structural information derivable from EPR. A brief survey of the present state of understanding of the optical bands caused by the defects is also given.
Article
ESR signals of quartz grains in fault gouge have been partially or completely reset by movements on the fault, which allows the dating of the last fault movement. In order to better understand the zeroing process, we have studied the variation in ESR signal, AD, and age in various grain sizes, since it can be expected that larger grains will be less affected by stress than smaller grains. We propose that a plateau of constant, lower age for the smallest grains indicates total resetting; this is confirmed in gouge from a fault in California. Only such samples should be used for dating.
Article
Wind-blown sand from Arago cave at Tautavel and beach sand from Terra Amata at Nice are studied for the dating by a quartz large grain technique using electron spin resonance (ESR). The signal intensity of Al center increased with artificial γ-ray dose, and total equivalent doses of 2030 ± 109 Gy and 1795 ± 103 Gy are obtained for Arago and Terra Amata samples respectively.A preliminary UV experiment shows that the Al center signal initially decreased under UV irradiation but approached a residual strength. ‘Zero age’ quartz samples taken from present beach sand near Terra Amata show a signal intensity corresponding to 18% of the saturated intensity of Terra Amata sample (this same proportion is 30% for the ‘zero age’ Arago samples). After the subtraction of this residual strength, paleodoses of 1010 ± 149 Gy and 750 ± 147 Gy and ages of 430 ± 85 kyr and 380 ± 80 kyr are deduced for Arago cave and Terra Amata, respectively. These ages are in good agreement with those estimated from the faunal studies of these sites.
Bois-des-Presles; MT-PIL"Mont-Pillard; SH: Sheet number; DATE: all dates were obtained by ESR expected for the youngest (95.5$4) which was obtained by U-Series method on a bone
  • Frev Fre´
  • Carp
  • Re-Nanc " Renancourt ; Sav " Saveuse ; Purg " Purgatoire ; Bois-Pr Carpentier
FREV"Fre´ ; CARP"Abbeville Carpentier quarry; RE-NANC"Renancourt; SAV"Saveuse; PURG"Purgatoire; BOIS-PR"Bois-des-Presles; MT-PIL"Mont-Pillard; SH: Sheet number; DATE: all dates were obtained by ESR expected for the youngest (95.5$4) which was obtained by U-Series method on a bone; POL: Magnetic polarity (see details in Laurent et al., 1994);
Cagny-L'Epinette; GAR"Cagny-la-Garenne; MAR"Mareuil-Caubert
  • L Ep
L'EP"Cagny-L'Epinette; GAR"Cagny-la-Garenne; MAR"Mareuil-Caubert;
Saint-Sauveur; ETOUV"Etouvie; BOUT"Boutmy-Muchembeld; MONTMontiè res; CAMB"Cambron
  • L Silt
  • G Gravel
  • St
  • Sauv
L"Silt, G"Gravel; ST-SAUV"Saint-Sauveur; ETOUV"Etouvie; BOUT"Boutmy-Muchembeld; MONTMontiè res; CAMB"Cambron; ARG"Argoeuvres;
ESR dating of quartz from Quaternary sediments: First attempt ESR dating of sediment baked by lava-flows: Comparison of paleodoses for Al and Ti centers Electron spin resonance (ESR) dating of bones of the Caune de l'Arago at Tautavel
  • J A Weil
  • —165 Yokoyama
  • Y Falguè Res
  • C Quaegebeur
  • J P Y Falguè Res
  • C Quaegebeur
  • J P Bibron
  • R Le´
  • C Nguyen
  • H V Poupeau
Weil, J.A. (1984) A review of electron spin spectroscopy and its application to the study of paramagnetic defects in cry-stalline quartz. Physics and Chemistry of Minerals, 10, 149—165. Yokoyama, Y.,Falguè res, C. and Quaegebeur, J.P. (1985) ESR dating of quartz from Quaternary sediments: First attempt. Nuclear ¹racks, 10, 4—6, 921—928. Yokoyama, Y.,Falguè res, C. and Quaegebeur, J.P. (1986) ESR dating of sediment baked by lava-flows: Comparison of paleodoses for Al and Ti centers. In: Ikeya, M. and Miki, T.F. (eds), ESR dating and dosimetry, IONICS, Tokyo, pp. 197—204. Yokoyama, Y., Quaegebeur, J.P., Bibron, R., Le´, C., Nguyen, H.V. and Poupeau, G. (1981) Electron spin resonance (ESR) dating of bones of the Caune de l'Arago at Tautavel. In: Lumley, H. de and Labeyrie, J. (eds), Absolute Dating and Isotope Analyses in Prehis-tory-Methods and, pp. 457—492. CNRS, Paris.
A new regional group of the Lower Palaeolithic in Brittany (France), recently dated by Electron Spin Resonance Dating of a volcanic rock by ESR Plio-Pleistocene continental record in Central Brittany (France) Fluviatile and estuarine sedimentation controlled by tectonism
  • V Medjdahl
  • —72 Monnier
  • J L Hallegoue¨
  • S Laurent
  • M Auguste
  • P Bahain
  • J J Falguè Res
  • C Gebhardt
  • A Marguerie
  • D Molines
  • N Morzadec
  • H Yokoyama
  • Y M Laurent
Medjdahl, V. (1979) Thermoluminescence dating: beta-dose attenu-ation in quartz grains. Archaeometry, 21, 61—72. Monnier, J.L., Hallegoue¨, S., Laurent, M., Auguste, P., Bahain, J.J.,Falguè res, C., Gebhardt, A., Marguerie, D., Molines, N., Morzadec, H. and Yokoyama, Y. (1994) A new regional group of the Lower Palaeolithic in Brittany (France), recently dated by Electron Spin Resonance. C.R. Academie Sciences Paris, 319, 155—160. Shimokawa, K., Imai, N. and Hirota, M. (1984) Dating of a volcanic rock by ESR. Isotope Geoscience, 2, 365—373. Tuffreau A. (1987) Le Paleó infe´ dans le nord de la France et en Picardie. Unpublished Thesis. Universite´ Lille. M. Laurent et al.: ESR dating of quartz extracted from Quaternary and Neogene sediments Van Vliet-Lanoe¨, F., Bonnet, S., Chauvel, J.J., Frette, B., Hallegoue¨ Hallegoueä Laurent, M. (1995) Plio-Pleistocene continental record in Central Brittany (France). Fluviatile and estuarine sedimentation controlled by tectonism. Paleobenthos »I,Congrè s international, Cagliari (I), 25—31 October 1995, IGCP 319—366.
fauna from fluvial silt of Cagny-la-Garenne and CagnyCimetiè re; CARP"fauna from white marls of Carpentier quarry
  • Gar Cim
GAR CIM"fauna from fluvial silt of Cagny-la-Garenne and CagnyCimetiè re; CARP"fauna from white marls of Carpentier quarry;
fauna from Grace gravel. bleached quartz give ages in agreement with stratig Le Quaternaire de la basse Somme: tentative desynthè se
  • R Agache
  • F Bourdier
  • And
  • R Petit
GRACE"fauna from Grace gravel. bleached quartz give ages in agreement with stratig-Agache, R., Bourdier, F. and et Petit, R. (1963) Le Quaternaire de la basse Somme: tentative desynthè se. Bull. Soc. geó. France, 422—442.