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drapeau

Faits marquants 2017

Mars 2017

The chronology of human and animal presence in the decorated and sepulchral cave of Cussac (France)
23 mars 2017
  In this article, we present a first synthesis of the chronology of Cussac Cave (Dordogne, SW France). This deep cavern (1.6 km), discovered in 2000, is very well preserved (e.g. intact floors) and thus favorable to research, especially given its rare association of parietal art and ... Lire la suite »
Early Neanderthal constructions deep in Bruniquel Cave in southwestern France
23 mars 2017
  Very little is known about Neanderthal cultures, particularly early ones. Other than lithic implements and exceptional bone tools, very few artefacts have been preserved. While those that do remain include red and black pigments and burial sites, these indications of modernity are ... Lire la suite »
Quantification of vertical solid matter transfers in soils during pedogenesis by a multi-tracer approach
23 mars 2017
Vertical transfer of solid matter in soils (bioturbation and translocation) is responsible for changes in soil properties over time through the redistribution of most of the soil constituents with depth. Such transfers are, however, still poorly quantified. In this study, we examine matter ... Lire la suite »
Unprecedented coring performance with the upgraded Research Vessel Marion Dufresne
20 mars 2017
The MD203 ACCLIMATE expedition was the first coring cruise onboard the Research Vessel Marion Dufresne since her midlife refit in 2015 (Rousseau et al. 2016). Taking place in March 2016 in the South Atlantic Roaring Forties and Howling Fifties, this cruise provided a full-scale exercise to test, in ... Lire la suite »
Carbon isotope offsets between benthic foraminifer species of the genus Cibicides (Cibicidoides) in the glacial sub-Antarctic Atlantic
20 mars 2017
Epibenthic foraminifer δ13C measurements are valuable for reconstructing past bottom water dissolved inorganic carbon δ13C (δ13CDIC), which are used to infer global ocean circulation patterns. Epibenthic δ13C may also reflect the influence of 13C-depleted phytodetritus, ... Lire la suite »
Temporal and spatial variations of freshwater reservoir ages in the Loire river watershed
20 mars 2017

In order to map the freshwater reservoir effect (FRE) variability of the Loire River and its tributaries, spatial and temporal carbon isotope (13C and 14C) analyses of the dissolved inorganic Carbon (DIC) were conducted.

 

Additional correction for interstitial water changes in XRF core-scanning data from long sedimentary cores
20 mars 2017
Fast and nondestructive X-ray fluorescence (XRF) core scanning provides high-resolution element data that are widely used in paleoclimate studies. However, various matrix and specimen effects prevent the direct use of semi-quantitative raw XRF core-scanning intensities for robust paleoenvironmental ... Lire la suite »
Magnetic fabric in weakly deformed sediments from Northern Apennine orogenic belt (Italy)
16 mars 2017
The anisotropy of magnetic susceptibility (AMS) gives access to the preferential alignment of elongated magnetic grains in sediments. This alignment arises from hydrodynamic forces at the time of deposition. When sediments are emerged and involved in an orogeny, they may be remobilized by the ... Lire la suite »
An interactive tool for navigation within a database of water and carbon stable isotope records from natural archives.
16 mars 2017
Past climate is an important benchmark to assess the ability of climate models to simulate key processes and feedback. Model–data comparisons can help to constrain the uncertainties associated with transfer functions. We have put together a global database of proxy records of oxygen (d18O), ... Lire la suite »
Vers une Physique Statistique des  Événements Extrêmes Climatiques
15 mars 2017
Pour l’instant, l’application de la théorie des valeurs extrêmes était limitée aux systèmes qui décrivent la dynamique d’un point dans le temps. Ce cadre est utile pour étudier des phénomènes physiques localisés ... Lire la suite »
Interglacials of the last 800,000 years
14 mars 2017
Interglacials, including the present (Holocene) period, are warm, low land ice extent (high sea level), end-members of glacial cycles. Based on a sea level definition, we identify eleven interglacials in the last 800,000 years. Data compilations suggest that despite spatial heterogeneity, Marine ... Lire la suite »
Evaluation of the warm marine air intrusion at the French Antarctic station Dumont d’Urville using water stable isotopes as an atmospheric tracer
07 mars 2017
During the austral summer 2016-17, an infrared spectrometer monitoring water stable isotopes in the vapour has been deployed by Camille Bréant from LSCE (Laboratoire des Sciences du Climat et de l’Environnement, Paris, France) at the coastal station of Dumont d’Urville in East ... Lire la suite »

Février 2017

Linking environmental changes with human occupations between 900 and 400 ka in Western Europe
02 février 2017
  Human occupation in Europe strongly fluctuated over the Quaternary. Archaeological records suggest an intermittent human occupation in Western Europe between 900 and 500 ka, especially in the north of Europe at latitude higher than 45°N. On the opposite, southern Europe, more stable ... Lire la suite »
Early Neanderthal constructions deep in Bruniquel Cave in southwestern France
02 février 2017
  Very little is known about Neanderthal cultures1, particularly early ones. Other than lithic implements and exceptional bone tools2, very few artefacts have been preserved. While those that do remain include red and black pigments3 and burial sites4, these indications of modernity are ... Lire la suite »
Extreme storms during the last 6500 years from lagoonal sedimentary archives in the Mar Menor (SE Spain)
02 février 2017
Storms and tsunamis, which may seriously endanger  human  society,  are  amongst  the  most  devastating  marine catastrophes that can occur in coastal areas. Many such events are known  and have been reported  for the Mediterranean, a region where ... Lire la suite »
 

Janvier 2017

Labelled microbial culture as a calibration medium for 13C-isotope measurement of derivatized compounds: application to tert-butyldimethylsilyl amino acids
26 janvier 2017
  RATIONALE: Compound-specific stable carbon isotope analysis by GC/C/IRMS is widely used in studies of environmental or biological functioning. In the case of derivatized molecules, a calibration might be required due to added non-analyte carbon and in some cases non-stoichiometric ... Lire la suite »
Fossil redox-conditions influence organic matter composition in loess paleosols
26 janvier 2017
  Abstract The soil memory recorded in paleosols of loess-paleosol sequences is an important contributor to our understanding of past climatic conditions. Molecular proxies based on the organic matter preserved in paleosols form an essential part of this record, but the long-term ... Lire la suite »
Quantification of vertical solid matter transfers in soils during pedogenesis by a multi-tracer approach
26 janvier 2017
PURPOSE Vertical transfer of solid matter in soils (bioturbation and translocation) is responsible for changes in soil properties over time through the redistribution of most of the soil constituents with depth. Such transfers are, however, still poorly quantified. MATERIALS AND METHODS In this ... Lire la suite »
 Palaeotemperature reconstruction during the Last Glacial from d18O of earthworm calcite granules from Nussloch loess sequence, Germany
26 janvier 2017
The Nussloch loess–palaeosol sequence (Rhine Valley, Germany) is considered to be one of the most complete records of the last glacial period in Western Europe due to its very high sedimentation rate and its good chronological control. This sequence is therefore a good framework in which to ... Lire la suite »
Late Pleistocene climate evolution in Southeastern Europe recorded by soil bacterial membrane lipids in Serbian loess
26 janvier 2017
Loess–paleosol sequences in the Vojvodina region in the southeastern Carpathian Basin have been intensively studied to obtain a high-resolution stratigraphical framework for the Upper Pleistocene in this part of Europe. In these studies, millennial-scale sedimentation variations in the Upper ... Lire la suite »
Vertical distribution of helium and 40Ar/36Ar in porewaters of the Eastern Paris Basin (Bure/Haute Marne): constraints on transport processes through the sedimentary sequence
26 janvier 2017
  As part of its ongoing project on repositories for high-activity, long-lived radioactive waste, a 2000 m deep borehole was drilled by the French Nuclear Waste Agency (ANDRA) in the layered structure of alternating aquifers and aquitards of the Eastern Paris Basin. Among the information ... Lire la suite »
Continuous measurements of isotopic composition of water vapour on the East Antarctic Plateau
16 janvier 2017
  Water stable isotopes in central Antarctic ice cores are critical to quantify past temperature changes. Accurate temperature reconstructions require to understand the processes controlling surface snow isotopic composition. Isotopic fractionation processes occurring in the atmosphere and ... Lire la suite »
Experimental determination and theoretical framework of kinetic fractionation at the water vapour–ice interface at low temperature
16 janvier 2017
  Water isotopes are commonly used for climate reconstruction from ice cores. The different heavy isotopes of water such as H218O, H217O or HDO give information about local temperature but also temperature and humidity of water vapour sources. Quantification of these parameters relies on ... Lire la suite »
Reconstruction du climat et de l’environnement des derniers 800 000 ans a partir des carottes de glace – variabilité orbitale et millénaire.
13 janvier 2017
  Abstract: Au cours des 40 dernières années, la recherche sur les carottes de glace a produit des résultats de référence pour l’évolution de la température polaire et de la composition atmosphérique au cours des 800 000 ... Lire la suite »
Acquisition of isotopic composition for surface snow in East Antarctica and the links to climatic parameters
12 janvier 2017
  Abstract: The isotopic compositions of oxygen and hydrogen in ice cores are invaluable tools for the reconstruction of past climate variations. Used alone, they give insights into the variations of the local temperature, whereas taken together they can provide information on the climatic ... Lire la suite »
Phase relationships between orbital forcing and the composition of air trapped in Antarctic ice cores
12 janvier 2017
Abstract: Orbital tuning is central for ice core chronologies beyond annual layer counting, available back to 60 ka (i.e. thousands of years before 1950) for Greenland ice cores. While several complementary orbital tuning tools have recently been developed using δ18Oatm, δO2⁄N2 ... Lire la suite »
 
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