A5020639290- Geology and Paleoclimatology Research
- Geological and Geophysical Studies
- Geological Studies and Exploration
- Hydrocarbon exploration and reservoir analysis
- Geological formations and processes
- Methane Hydrates and Related Phenomena
- Archaeology and ancient environmental studies
- Isotope Analysis in Ecology
- Pleistocene-Era Hominins and Archaeology
- Geochemistry and Elemental Analysis
- Coral and Marine Ecosystems Studies
- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Paleontology and Stratigraphy of Fossils
- Groundwater and Isotope Geochemistry
- Forensic Anthropology and Bioarchaeology Studies
- Pacific and Southeast Asian Studies
- Ocean Acidification Effects and Responses
- Soil erosion and sediment transport
- Geological and Geochemical Analysis
- Marine Bivalve and Aquaculture Studies
- Heavy metals in environment
- earthquake and tectonic studies
- Archaeological and Geological Studies
- Diverse Musicological Studies
Laboratoire des Sciences du Climat et de l'Environnement
2015-2024
CEA Paris-Saclay
2013-2023
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2013-2023
Université de Versailles Saint-Quentin-en-Yvelines
2014-2023
Université Paris-Saclay
2016-2023
Centre National de la Recherche Scientifique
2013-2023
Archéologie et Archéométrie
2014-2023
Abstract Rapid changes in ocean circulation and climate have been observed marine-sediment ice cores over the last glacial period deglaciation, highlighting non-linear character of system underlining possibility rapid shifts response to anthropogenic greenhouse gas forcing. To date, these are still not fully explained. One obstacle hindering progress our understanding interactions between past is difficulty accurately dating marine cores. Here, we present a set 92 sediment from Atlantic...
Abstract This work presents iron isotope data in the western equatorial Pacific. Marine aerosols and top core margin sediments display a slightly heavy Fe isotopic composition ( δ 56 Fe) of 0.33 ± 0.11‰ (2SD) 0.14 0.07‰, respectively. Samples reflecting influence Papua New Guinea runoff (Sepik River Rabaul volcano water) are characterized by crustal values. In seawater, is mainly supplied particulate form found with between −0.49 0.34 0.07‰. The seems to be brought transported across...
Abstract During the last glacial period, Greenland's climate shifted between cold (stadial) and warm (interstadial) phases that were accompanied by ocean circulation changes characterized reduced Atlantic Meridional Overturning Circulation (AMOC) during stadials. Here we present new data from western tropical demonstrating AMOC slowdowns preceded some of large South American rainfall events took place Based on 231 Pa/ 230 Th Ti/Ca measurements in same sediment core, determine started to...
Boron isotopes in marine carbonates are increasingly used to reconstruct seawater pH and atmospheric pCO 2 through Earth’s history. While isotope ratio measurements from individual laboratories often of high quality, it is important that records generated different can equally be compared. Within this Isotope Intercomparison Project (BIIP), we characterised the boron isotopic composition (commonly expressed δ 11 B) two carbonates: Geological Survey Japan carbonate reference materials JCp‐1...
Abstract This paper aims to define the first chrono-cultural framework on domestication and early diffusion of opium poppy using small-sized botanical remains from archaeological sites, opening way directly date minute short-lived samples. We produced initial set radiocarbon dates eleven Neolithic sites (5900–3500 cal BCE) in central western Mediterranean, northwestern temperate Europe, Alps. When possible, we also dated macrobotanical originating same sediment sample. In total, 22 samples...
The first inter-calibration study of the stable silicon isotope composition dissolved silicic acid in seawater,<italic>δ</italic><sup>30</sup>Si(OH)<sub>4</sub>, is presented as a contribution to international GEOTRACES program.
Abstract The Southern Ocean plays a pivotal role in the control of atmospheric CO 2 levels, via both physical and biological sequestration processes. carbon transfer to ocean interior is tightly coupled availability other elements, especially iron as trace‐limiting nutrient dissolved silicon mineral substrate that allows diatoms dominate primary production. Importantly, variations cycling are large but not well understood. Here we use δ 30 Si measurements track seasonal flows silica deep...
Abstract. Thanks to its optimal location on the northern Brazilian margin, core MD09-3257 records both ocean circulation and atmospheric changes. The latter occur locally in form of increased rainfall adjacent continent during cold intervals recorded Greenland ice North Atlantic sediment cores (i.e., stadials). These events are as peaks ln(Ti ∕ Ca). New sedimentary Pa Th data indicate that mid-depth western equatorial water mass transport decreased all stadials last 40 kyr. Using...
Pastoral nomadism is of great cultural and economic importance in several regions the world today. However, documenting ancient patterns mobility societies where pastoralism was central challenging requires tailored approaches methodologies. Here we use strontium, oxygen carbon isotopic analyses dental enamel, together with a local strontium isoscape, to reconstruct seven domestic horses deposited Late Bronze Age grave from western Mongolia. Radiocarbon indicates that animals were within...
Because hard tissues can be radiocarbon dated, they are key to establishing the archaeological chronologies, palaeoenvironmental reconstructions and historical-biogeographical processes of last 50,000 years. The advent accelerator mass spectrometers (AMS) has revolutionized field archaeology but routine AMS dating still requires 60-200 mg bone, which far exceeds that small vertebrates or remains hold a patrimonial value (e.g. hominid worked bone artefacts). Here, we present first dates...
Abstract. We reconstruct the geometry and strength of Atlantic meridional overturning circulation during Heinrich stadial 2 three Greenland interstadials 20–50 ka period based on comparison new published sedimentary 231Pa / 230Th data with simulated 230Th. show that deep these was very different from Holocene. Northern-sourced waters likely circulated above 2500 m depth, a flow rate lower than present-day North water (NADW). Southern-sourced most probably flowed northwards below 4000 depth...
Most oceanic islands are due to excess volcanism caused by thermal and/or compositional mantle melting anomalies. We call attention here another class of islands, not but vertical motions blocks lithosphere related transform tectonics. Sunken tectonic capped carbonate platforms have been previously identified along the Vema and Romanche transforms in equatorial Atlantic. reprocessed seismic reflection lines, did new facies analyses 87 Sr/ 86 Sr dating samples from platforms. A 50 km long...
The question of when the first humans arrived in New World has been a bone contention for several decades. Similarly, age rock paintings heatedly debated. Settlements Serra da Capivara National Park have dated to between 5 kyr and >50 kyr, which is far older than Clovis barrier. Moreover, calcite formation on rock-wall painting rockshelter yielded thermoluminescence (TL) electron paramagnetic resonance (EPR) ages 35 BP (Watanabe et al. 2003). In an attempt contribute this ongoing debate,...
Abstract εNd and normalized Rare Earth Elements (REE) patterns of benthic planktonic foraminifera Fe‐Mn coatings precipitated on sediments have been investigated for the South China Sea (SCS) to (1) assess reliability extraction past seawater in SCS (2) reconstruct hydrological changes during last 25 kyr. Reductively cleaned mono‐specific ( Globigerinoides ruber ) mixed core‐top from 1500 2400 m display similar values those modern Pacific Deep Water (PDW) (εNd −3.9 −4.4). Furthermore,...
Rationale Laser Ablation coupled to Multi‐Collector Inductively Coupled Plasma Mass Spectrometry (LA‐MC‐ICPMS) is a powerful tool for the high‐precision measurement of isotopic ratios many elements in geological samples, with isotope ratio ( 11 B/ 10 B) boron being used as an indicator pH oceanic waters. Most samples or standards are polished and ablation occurs on flat surfaces. However, shape irregularities marine biocarbonates (e.g., corals, foraminifera) can make precise measurements...
Abstract Excess 231 Pa and 230 Th ( xs ) can be used to reconstruct past oceanic sedimentation Th‐normalized flux) circulation changes (( Pa/ Th) xs,0 , hereafter Pa/Th). These quantities are determined by computing the detrital authigenic contributions from bulk sediment measurement. The method relies on use of a chosen constant value 238 U/ 232 activity ratio (hereafter (U/Th) det ). In this study, we have extracted fraction sediments North Atlantic deep‐sea core SU90‐08 (43°03′1N,...