Ist vs. IInd Mesolithic in southern France. Functional approach of techno-economic behavior through the Castelnovian of Montclus rock shelter (Gard): First results

2016 ◽  
Vol 423 ◽  
pp. 242-251 ◽  
Author(s):  
Sylvie Philibert
2021 ◽  
Author(s):  
Annette Kadereit ◽  
Nora Pfaffner ◽  
Sebastian Kreutzer ◽  
Tianhao Wang ◽  
Sophie Cornu ◽  
...  

<p>Loess-palaeosol sequences are most important archives for reconstructing terrestrial palaeoenvironments. However, in the European Mediterranean, these archives are surprisingly scarcely investigated. In southern France, respective sediment-soil archives were last investigated in more detail in the middle of the last century, when major construction works in the region provided access to numerous loess exposures. However, this was before the breakthrough of luminescence-dating as a major chronometric method for the Later Pleistocene. Thus, the loess was poorly dated. Later, Mediterranean loess archives attracted fewer researchers than their central-European counterparts. Reasons for this may be that, compared to the loess belt of temperate Europe, Mediterranean loess deposits are often reworked and mixed with slope deposits. Moreover, palaeosols that developed during climate ameliorations of the last glacial period seem to reflect less pronounced temperature and humidity shifts than those in temperate regions. The most prominent palaeosol developed within the last-glacial loess in the Rhône Valley is a brown palaeosol with large carbonate concretions at its base. However, it is usually severely truncated.</p><p>We allocated joint research efforts from groups in Germany and France to track last-glacial sedimentation and climate shifts in loess-palaeosol sections along the Rhône Valley, south of the confluence of the River Saone at Lyon. Thereby, optically stimulated luminescence (OSL) dating serves as a vital tool for establishing chronometries for the loess-palaeosol sections in southern France, with first results from the Rhône Valley in Bosq et al. (2018, 2020). We summarize results from two sites that are regarded as key sections for palaeoenvironmental reconstruction along the Rhône Valley as evaluated from inspections during fieldwork, complemented by several smaller sections. Our presentation focusses on challenges met with OSL dating attempts of these Mediterranean archives and first achievements in backing the stratigraphies established by sediment-soil analyses in the field and laboratory by chronometric data.</p><p><strong>References</strong></p><p>Bosq, M., Bertran, P., Degeai, J.-P., Kreutzer, S., Queffelec, A., Moine, O., Morin, E., 2018. Last Glacial aeolian landforms and deposits in the Rhône Valley (SE France): Spatial distribution and grain-size characterization. Geomorphology 318, 1–20. doi:10.1016/j.geomorph.2018.06.010</p><p>Bosq, M., Kreutzer, S., Bertran, P., Degeai, J.-P., Dugas, P., Kadereit, A., Lanos, P., Moine, O., Pfaffner, N., Queffelec, A., Sauer, D., 2020. Chronostratigraphy of two Late Pleistocene loess-palaeosol sequences in the Rhône Valley (southeast France). Quaternary Science Reviews 245, 106473. doi:10.1016/j.quascirev.2020.106473</p>


2016 ◽  
Vol 7 ◽  
pp. 06001 ◽  
Author(s):  
Freddy Vinet ◽  
Laurent Boissier ◽  
Clotilde Saint-Martin

1998 ◽  
Vol 19 (3) ◽  
pp. 285-293 ◽  
Author(s):  
Edouard Le Floc'h ◽  
James Aronson ◽  
Shivcharn Dhillion ◽  
Jean-Louis Guillerm ◽  
Anna Grossmann ◽  
...  

AmS-Skrifter ◽  
2019 ◽  
pp. 21-34
Author(s):  
Melie Le Roy ◽  
Stéphane Rottier ◽  
Frédéric Santos ◽  
Anne-Marie Tillier

In France, collective burial sites of the Late Neolithic period (3600-2100 BC) include a variety of structures ranging from simple pits and natural caves to hypogea and megalithic structures. The management of these graves raises questions about their representativeness and about burial practices involving non-adult individuals. This study of funerary selection based on age-at-death compares the results obtained for different sites and offers several potential interpretations concerning the integration of immature individuals in these collective tombs based on their age. The study highlights a particular selection observed in various funerary structures and a chronological difference between northern and southern France. These first results lead to a discussion of distinct cultural choices among different geographical areas.


1976 ◽  
Vol 32 ◽  
pp. 577-588
Author(s):  
C. Mégessier ◽  
V. Khokhlova ◽  
T. Ryabchikova

My talk will be on the oblique rotator model which was first proposed by Stibbs (1950), and since received success and further developments. I shall present two different attempts at describing a star according to this model and the first results obtained in the framework of a Russian-French collaboration in order to test the precision of the two methods. The aim is to give the best possible representation of the element distributions on the Ap stellar surfaces. The first method is the mathematical formulation proposed by Deutsch (1958-1970) and applied by Deutsch (1958) to HD 125248, by Pyper (1969) to α2CVn and by Mégessier (1975) to 108 Aqr. The other one was proposed by Khokhlova (1974) and used by her group.


1976 ◽  
Vol 32 ◽  
pp. 109-116 ◽  
Author(s):  
S. Vauclair

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.


Author(s):  
H. Seiler ◽  
U. Haas ◽  
K.H. Körtje

The physical properties of small metal particles reveal an intermediate position between atomic and bulk material. Especially Ag has shown pronounced size effects. We compared silver layers evaporated in high vacuum with cluster layers of small silver particles, evaporated in N2 at a pressure of about 102 Pa. The investigations were performed by electron optical methods (TEM, SEM, EELS) and by Photoacoustic (PA) Spectroscopy (gas-microphone detection).The observation of cluster layers with TEM and high resolution SEM show small silver particles with diameters of about 50 nm (Fig. 1 and Figure 2, respectively). The electron diffraction patterns of homogeneous Ag layers and of cluster layers are similar, whereas the low loss EELS spectra due to plasmon excitation are quite different. Fig. 3 and Figure 4 show first results of EELS spectra of a cluster layer of small silver particles on carbon foil and of a homogeneous Ag layer, respectively.


Author(s):  
H.S. von Harrach ◽  
D.E. Jesson ◽  
S.J. Pennycook

Phase contrast TEM has been the leading technique for high resolution imaging of materials for many years, whilst STEM has been the principal method for high-resolution microanalysis. However, it was demonstrated many years ago that low angle dark-field STEM imaging is a priori capable of almost 50% higher point resolution than coherent bright-field imaging (i.e. phase contrast TEM or STEM). This advantage was not exploited until Pennycook developed the high-angle annular dark-field (ADF) technique which can provide an incoherent image showing both high image resolution and atomic number contrast.This paper describes the design and first results of a 300kV field-emission STEM (VG Microscopes HB603U) which has improved ADF STEM image resolution towards the 1 angstrom target. The instrument uses a cold field-emission gun, generating a 300 kV beam of up to 1 μA from an 11-stage accelerator. The beam is focussed on to the specimen by two condensers and a condenser-objective lens with a spherical aberration coefficient of 1.0 mm.


Author(s):  
W.W. Adams ◽  
G. Price ◽  
A. Krause

It has been shown that there are numerous advantages in imaging both coated and uncoated polymers in scanning electron microscopy (SEM) at low voltages (LV) from 0.5 to 2.0 keV compared to imaging at conventional voltages of 10 to 20 keV. The disadvantages of LVSEM of degraded resolution and decreased beam current have been overcome with the new generation of field emission gun SEMs. In imaging metal coated polymers in LVSEM beam damage is reduced, contrast is improved, and charging from irregularly shaped features (which may be unevenly coated) is reduced or eliminated. Imaging uncoated polymers in LVSEM allows direct observation of the surface with little or no charging and with no alterations of surface features from the metal coating process required for higher voltage imaging. This is particularly important for high resolution (HR) studies of polymers where it is desired to image features 1 to 10 nm in size. Metal sputter coating techniques produce a 10 - 20 nm film that has its own texture which can obscure topographical features of the original polymer surface. In examining thin, uncoated insulating samples on a conducting substrate at low voltages the effect of sample-beam interactions on image formation and resolution will differ significantly from the effect at higher accelerating voltages. We discuss here sample-beam interactions in single crystals on conducting substrates at low voltages and also present the first results on HRSEM of single crystal morphologies which show some of these effects.


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