ESR dating of fluvial quartz: Estimate of the minimal distance transport required for getting a maximum optical bleaching     

Pierre Voinchet  Christophe Falgures  Hlne Tissoux  Jean-Jacques Bahain  Jackie Desprie  Florence Pirouelle 《Quaternary Geochronology》2007,2(1-4):363-366

An ESR experimental study of artificial optical bleaching of sedimentary quartz has shown that the aluminum center was maximally bleached after a 6-month illumination equivalent to natural light. This duration seems too long to apply in natural conditions. Nevertheless, the measurement of the ESR intensity of aluminum centers in quartz extracted from modern sediments and deposited in sandy bars shows that the maximum bleaching has effectively been reached.

In order to determine the relationship between the bleaching and the distance covered by a quartz grain in a river, samples were collected along the Creuse River (France) from its spring to about 170 km downstream, where maximum bleaching levels were observed in previous studies. The ESR intensities of the aluminum and titanium centers in quartz were measured, using X-band spectroscopy, before and after artificial bleaching. The difference measured between these sub-samples shows that the maximum bleaching level is obtained in the course of the first kilometer. Hence, the assumption that ESR dating of fluvial sediment is based on the optical bleaching was validated.  相似文献   

ESR dating in Song Terus cave (East Java, Indonesia)     

S. Hameau  C. Falgures  J.J. Bahain  F. Smah  A.M. Smah  J.M. Dolo 《Quaternary Geochronology》2007,2(1-4):398-402

Electron spin resonance (ESR) dating on teeth has been used to determine the antiquity of the human presence in the area of Gunung Sewu (East Java, Indonesia). The Song Terus cave is one of the archaeological sites located in this area, which has yielded an important collection of fossil bones and prehistoric lithic industry. ESR dating shows that this cave belongs to a karstic system which has been in place since Middle Pleistocene. The results of coupled ESR/Uranium-series dating indicates closed system for uranium in tooth tissues yielding ages of between 216 and 392 ka for the oldest archaeological levels, confirming the possibility of finding Middle Pleistocene human occupations in such karstic sites in Java.  相似文献   

On the interest and the limits of using combined ESR/U-series model in the case of very late uranium uptake     

C. Falgures  J.-J. Bahain  J.-M. Dolo  N. Mercier  H. Valladas 《Quaternary Geochronology》2007,2(1-4):403-408

Before ESR/U-series models were applied to ungulate teeth, it is generally assumed that calculated ages are close to the “real” ages when they range between the values obtained with the EU and LU models. When the samples show signs of uranium-leaching, a realistic mathematical modelling of the age is not possible. On the other hand, some samples have undergone a very late U-uptake “affecting” directly the U-series ages and rendering the calculated ages younger.

We present results obtained on two open-air sites, which show the limits of such combined models in the case of late uranium incorporation. For the Middle Pleistocene site of Isernia la Pineta (Italy), the ESR dates are expected to fall within the limits imposed by the Ar–Ar results. The other site, the Lower Palaeolithic deposits of Ambrona (Spain), yielded two sets of samples: some at the top of the sequence with uranium uptake ranging between EU and LU limits and thus giving a good idea of the “real” age of the site; others at the base displaying a very late U-uptake, which render an age determination difficult.  相似文献   

The challenge of dating early pleistocene fossil teeth by the combined uranium series–electron spin resonance method: the Venta Micena palaeontological site (Orce,Spain)     

Mathieu Duval  Christophe Falguères  Jean‐Jacques Bahain  Rainer Grün  Qingfeng Shao  Maxime Aubert  John Hellstrom  Jean‐Michel Dolo  Jordi Agusti  Bienvenido Martínez‐Navarro  Paul Palmqvist  Isidro Toro‐Moyano 《第四纪科学杂志》2011,26(6):603-615

The palaeontological site of Venta Micena (Orce, Andalusia, Spain) lies in the eastern sector of the Guadix–Baza basin, one of the best documented areas in Europe for Plio‐Pleistocene biostratigraphy. The combination of biochronological and palaeomagnetic results, combined with the radiometric data obtained for Atapuerca Sima del Elefante, indicated that the Venta Micena stratum was formed between the Jaramillo and Olduvai palaeomagnetic events, most likely between 1.22 and 1.77 Ma. Five fossil teeth from two outcrops (sites A and B) were selected to assess the potential of combined uranium series–electron spin resonance (US‐ESR) dating of Early Pleistocene sites. Although the US‐ESR results of the first outcrop showed a large scatter between the three teeth, the mean age of 1.37 ± 0.24 Ma can be considered a reasonable age estimate for Venta Micena. The mean ESR age of 0.62 ± 0.03 Ma obtained for site B seems to be a severe underestimation when compared with the independent age control. This underestimation is attributed to a relative recent U‐mobilization event that led to some U‐leaching. The results show that any ESR age calculations of old samples are extremely sensitive to variations in the measured ²³⁰Th/²³⁴U ratios in dental tissues. Although the results demonstrate that ESR can in principle be applied to Early Pleistocene sites, they also reveal the complexity of dating such old teeth. It is necessary to continue research in several directions, such as study of the behaviour of ESR signals in old teeth and understanding recent U‐mobilization processes, to improve the reliability of the combined US‐ESR dating method applied to Early Pleistocene times, a period for which the number of available numerical dating techniques is very limited. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

The 1‐million‐year‐old quartz assemblage from Pont‐de‐Lavaud (Centre,France) in the European context          下载免费PDF全文

Jackie Despriée  Marie‐Hélène Moncel  Marta Arzarello  Gilles Courcimault  Pierre Voinchet  Jean‐Jacques Bahain  Christophe Falguères 《第四纪科学杂志》2018,33(6):639-661

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ESR chronology of alluvial deposits and first human settlements of the Middle Loire Basin (Region Centre,France)     

P. Voinchet  J. Despriée  H. Tissoux  C. Falguères  J.-J. Bahain  R. Gageonnet  J. Dépont  J.-M. Dolo 《Quaternary Geochronology》2010,5(2-3):381-384

Since 1970, many prehistoric sites have been discovered in the alluvial terraces of several rivers of the Middle Loire River basin (France). During the last decade, the stepped-terraces systems of three of the Loire tributaries, the Creuse, the Cher and the Loir Rivers, were the focus of multidisciplinary studies, involving Quaternary geology, prehistory and geochronology. The geochronological data now available for these systems were mainly obtained by electron spin resonance (ESR) method applied to optically bleached fluvial quartz. These results provide a chronological framework for the evolution of fluvial systems and the human settlements of this area during Lower and Middle Pleistocene. Two phases of human settlement could be distinguished, around 1.1 Ma (Early Palaeolithic – Mode 1) and around 0.7 Ma ago (Acheulean – Mode II).  相似文献   

OSL and ESR studies of Aeolian quartz from the Upper Pleistocene loess sequence of Nussloch (Germany)     

H. Tissoux  H. Valladas  P. Voinchet  J.L. Reyss  N. Mercier  C. Falguères  J.-J. Bahain  L. Zöller  P. Antoine 《Quaternary Geochronology》2010,5(2-3):131-136

As part of a chronological study of the famous Upper Pleistocene Nussloch (Germany) loess sequence, three samples were collected to check the applicability of palaeodosimetric dating methods (OSL and ESR) to quartz grains. The ESR-multicentre method showed a partial bleaching of the ESR centers in aeolian sands. This partial bleaching was also observed by OSL. Laminated loess seemed to be sufficiently bleached but showed a large scatter of the doses, which we ascribed to heterogeneous responses of the luminescent grains to the SAR protocol. Ages could nevertheless be calculated for the three samples and were found to be somewhat older than the IRSL and ¹⁴C ages obtained for the same layers of the laminated loess.  相似文献   

ESR dating of Pleistocene archaeological localities of the Nihewan Basin,North China – Preliminary results     

Chun-Ru Liu  Gong-Ming Yin  Lu Gao  Jean-Jacques Bahain  Jian-Ping Li  Min Lin  Shi-Ming Chen 《Quaternary Geochronology》2010,5(2-3):385-390

The well-developed, late Cenozoic Nihewan Beds in northern China are amongst the most famous and well-preserved Quaternary strata in East Asia. The Nihewan Basin is also well-known for its mammalian fossils and stone artifacts, which document early human settlements in high northern latitudes (around 40°N). It is a key geological place to study palaeoenvironments and ancient human activities due to the excellent age-control of the formation by palaeomagnetism. In the present paper, the sediments of two Paleolithic sites were dated using the ESR signals of the titanium center in quartz. In order to check the reliability of our analytical procedures, a reference sample collected near the Brunhes/Matuyama (B/M) boundary at the Donggutuo site was firstly analyzed, yielding an age of 750 ± 88 ka. Then, three samples collected from the Dongpo site were analyzed by the same procedures. Our ESR results indicate that the age of the Dongpo cultural layer ranges between 304 ± 12 ka and 333 ± 23 ka, with an average of approximately 321 ± 15 ka.  相似文献   

ESR chronology of the Somme River Terrace system and first human settlements in Northern France   总被引：1，自引：0，他引：1  

Jean-Jacques Bahain  Christophe Falgures  Michel Laurent  Pierre Voinchet  Jean-Michel Dolo  Pierre Antoine  Alain Tuffreau 《Quaternary Geochronology》2007,2(1-4):356-362

The Somme Valley, Northern France, is famous for its archaeological sequence, where numerous rich Palaeolithic sites, such as Saint-Acheul, the type site of the Acheulian, have been discovered. The archaeological levels are often directly associated with fossil alluvial sediments of the River Somme or with slope deposits, including loess and palaeosols. In the middle reaches of the valley, near Amiens, the system of fossil-stepped fluvial terraces is particularly well developed and preserved, and occurs on 10 alluvial formations. These terraces, from +5 to +55 m above the present-day valley bedrock, allow the study of the environmental changes and the human settlement of this area through the Pleistocene.

Since 1988, ESR dating was systematically applied on bleached quartz extracted from the fossil fluvial deposits, in order to better describe the geological evolution of the stepped system. More recently, U-series/ESR dating has also been performed on teeth collected from the different terrace deposits. Here we present a synthetic review of the main ESR results, and propose an ESR chronology for the geological evolution of the Somme fluvial system and for the Middle Pleistocene human settlement of northern France.  相似文献   

Apport des marqueurs isotopiques et biogéochimiques dans la reconstitution du paléoenvironnement de la grotte du Lazaret (Nice,Alpes-Maritimes) au cours du Pléistocène supérieur (stade isotopique 5)     

Louis Rousseau  Jacques Beauchamp  Christophe Falguères  Christophe Emblanch  Dominique Genty  Jean-Jacques Bahain  Dominique Blamart 《Comptes Rendus Geoscience》2005,337(15):1348-1354

The isotopic composition of calcite from the stalagmitic floor E of the Lazaret Cave is interpreted as proxy of atmospheric circulation and vegetal cover changes during IOS 5. The ${\delta }^{18}\mathrm{O}$ variations could indicate change in precipitation sources, which could originate from the Mediterranean Sea during warm periods and from the Atlantic Ocean during colder periods. The ${\delta }^{13}\mathrm{C}$ variations could be related to vegetal cover and soil type. Tree cover appears to be dominant according to pollen spectra, and organic molecules trapped into calcite (sterols, terpenoids, humic acids). To cite this article: L. Rousseau et al., C. R. Geoscience 337 (2005).  相似文献