Updated calibration of the clumped isotope thermometer in planktonic and benthic foraminifera
Accurate reconstruction of past ocean temperatures is of critical importance to paleoclimatology. Carbonate clumped isotope thermometry (“Δ47 ”) is a relatively recent technique based on the strong relationship between calcification temperature and the statistical excess of 13C–18O bonds in carbonates. Its application to foraminifera holds great scientific potential, particularly because Δ47 paleotemperature reconstructions do not require assumptions regarding the 18O composition of seawater. However there are still relatively few published observations investigating the potential influence of parameters such as salinity or foraminiferal size and species. We present a new calibration data set based on 234 replicate analyses of 9 planktonic and 2 benthic species of foraminifera collected from recent core-top sediments, with calcification temperatures ranging from −2 to 25 °C. We observe a strong relationship between Δ47 values and independent, oxygen-18 estimates of calcification temperatures:
Δ47 = 41.63 × 103/T2 + 0.2056
The formal precision of this regression (± 0.7–1.0 °C at 95 % confidence level) is much smaller than typical analytical errors. Our observations confirm the absence of significant species-specific biases or salinity effects. We also investigate potential foraminifer size effects between 200 and > 560 μm in 6 species, and conclude that all size fractions from a given core-top location and species display statistically undistinguishable Δ47 values. These findings provide a robust foundation for future inter-laboratories comparisons and paleoceanographic applications.
(Geochimica et Cosmochimica Acta. vol. 239, n° 0016-7037, pp. 1-16, 01/09/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPG-ANGERS, LPG, UA, UN UFR ST, UN, INSU - CNRS, CNRS, CLIMAG, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA
FAME (v1.0): a simple module to simulate the effect of planktonic foraminifer species-specific habitat on their oxygen isotopic content
The oxygen-18 to oxygen-16 ratio recorded in fossil planktonic foraminifer shells has been used for over 50 years in many geoscience applications. However, different planktonic foraminifer species generally yield distinct signals, as a consequence of their specific living habitats in the water column and along the year. This complexity is usually not taken into account in model-data integration studies. To overcome this shortcoming, we developed the Foraminifers As Modeled Entities (FAME) module. The module predicts the presence or absence of commonly used planktonic foraminifers and their oxygen-18 values. It is only forced by hydrographic data and uses a very limited number of parameters, almost all derived from culture experiments. FAME performance is evaluated using the Multiproxy Approach for the Reconstruction of the Glacial Ocean surface (MARGO) Late Holocene planktonic foraminifer cal-cite oxygen-18 and abundance datasets. The application of FAME to a simple cooling scenario demonstrates its utility to predict changes in planktonic foraminifer oxygen-18 to oxygen-16 ratio in response to changing climatic conditions.
(Geoscientific Model Development. vol. 11, n° 1991-9603, pp. 3587-3603, 01/09/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, CLIM, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Gestion et valorisation des carottes sédimentaires à but scientifique en France : vers un système intégré
Les carottes sédimentaires font l'objet d'un intérêt grandissant de la part des paléo-environnementalistes mais également d’écologues qui s'intéressent à la trajectoire des écosystèmes (Pansu et al., 2015; Perga et al., 2015). Les carottes marines ou continentales prélevées dans le cadre de consortiums internationaux (IODP, ICDP) donnent l’exemple depuis des décennies en terme de partage d’échantillons pour ce type d’étude ; plus récemment l’augmentation de ré-études massives de données publiées (Bolliet et al., 2016; Cartapan is et al., 2016) démontrent la valeur de ces échantillons et des données associées. De leur côté depuis quelques années, les législateurs et financeurs poussent à l’ouverture, au partage et à la traçabilité des données : on peut citer l’OCDE, l’UE, l’ERC... Comment notre communauté peut-elle s’inscrire au quotidien dans ces processus qui demandent de profonds changements culturels dans nos pratiques de recherche ? C’est pour tenter d’apporter une réponse à cette question que nous avons cherché à développer un système intégré de captation et de gestion des métadonnées des échantillons issus de forages scientifiques, qui puisse être implémenté au niveau national et connecté à des initiatives internationales, sur lequel pourront venir s’appuyer les futurs Plans de Gestion de Données. Par une approche bottom-up, pragmatique et au plus près des pratiques des équipes de recherche, nombreuses, dispersées, aux moyens inégaux, et en s’appuyant sur des initiatives existantes, nous tentons de répondre petit à petit à différents niveaux - de la mission de prélèvement jusqu'à leur stockage, en passant par la mise à disposition, le suivi et la valorisation des échantillons et des métadonnées qui leur sont associées. Des avancées rapides ont pu être obtenues par la rencontre entre une communauté de paléoécologues et des équipes techniques novatrices dans le domaine du partage et de l’interopérabilité mêlant des informaticiens, géomaticiens, curateurs d’échantillons et de données. Cette dynamique s’appuie sur 3 projets nationaux (Cyber-Carothèque nationale s/c Equipex CLIMCOR ANR-11-EQPX-0009 ; QR-Code LTSER- France ; ROZA LTSER-France) et s’inscrit dans le cadre du Centre de Carottage et de Forage National (C2FN), une cellule de la division technique de l’INSU. Nous présenterons dans cette intervention 4 outils qui seront à court terme interconnectés : i)CoreBOOK, une application mobile de terrain dédiée à la captation des métadonnées de forage ; ii) le portail de la cyber-carothèque national, un hub accueillant les données nouvellement acquises et les inventaires de carothèques ; iii) Collec-Science, outil générique de gestion de collections d’échantillons naturels adapté à nos besoins (s/c projet QrCODE); enfin iv) ROZA (Rétro-Observatoire des Zones Ateliers), un prototype de découvreur et visualiseur de données destiné à favoriser la réutilisation des échantillons et des données paléoenvironnementales en mettant à disposition les données essentielles à la capitalisation des connaissances d’études successives sur un même site. Les perspectives aujourd'hui sont grandes, le système modulaire qui commence à se dessiner doit permettre à chacun de trouver son compte, à son rythme, où opérationnel peut enfin rimer avec standardisation, traçabilité et interopérabilité tout en conservant une utilisabilité au plus proche des activités et besoins quotidiens des chercheurs et personnels d’accompagnement, afin d’opérer un virage en douceur vers des pratiques de la science dite « ouverte
(01/09/2026)
EDYTEM, USMB [Université de Savoie] [Université de Chambéry], CNRS, Fédération OSUG, DTI, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMD, INSU - CNRS, X, IP Paris, ENPC, SU, CNRS, ENS-PSL, PSL, OASU, UB, INSU - CNRS, ULR, CNRS, INRAE, LCE, CNRS, UMLP, UBFC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEDI, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GRESE, UNILIM, DYNAFOR, INRA, ENSAT, INP-ENSAT, AgroToulouse, INP-AgroToulouse, Toulouse INP, Comue de Toulouse, Toulouse INP, Comue de Toulouse, LEHNA IPE, LEHNA, UCBL, ENTPE, CNRS, LIENSs, INSU - CNRS, ULR, CNRS, UR EABX, IRSTEA, LETG - Brest, LETG, UNICAEN, NU, UA, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN, GEOTRAC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GLACCIOS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA
A Bayesian approach to estimate biodynamic model parameters: bioaccumulation of PCB 153 by the freshwater crustacean Gammarus fossarum
The first step to evaluate the effects of contamination on organisms is to study toxicokinetics. The bioaccumulation of contaminants by aquatic species is a variable phenomenon, since it depends on the characteristics of the environment, the properties of the contaminants and the species. Different toxicokinetic models have been developed to describe the accumulation of contaminants in aquatic food webs. In these models, the organism is often considered as a single compartment: the bioaccumulation is then described as the balance between uptake and elimination processes. The absorption process can involve both dissolved or trophic route. The diet of aquatic organisms is known to be an important route of bioaccumulation of contaminants. The elimination process includes excretion, metabolism and dilution by growth. To date, there are few models focusing on persistent organic contaminants. Furthermore, estimating models' parameters is generally done through a frequentist approach in two steps: first by estimating parameter(s) related to depuration and then estimating parameter(s) related to accucumulation. The problem by doing this is that depuration during the accumulation phase is neglected, while this process occurs in the two phases. The aim of our study is to propose a Bayesian framework to estimate the parameters of a biodynamic model together by considering simultaneously accumulation and depuration data. The posterior distribution obtained for all parameter will enable a more accurate assessment of bioaccumulation uncertainty. We illustrate our approach with the freshwater benthic invertebrate Gammarus fossarum exposed for 7 days to a sediment spiked with PCB153 and transferred to a clean media for 7 more days. The PCB153 concentrations in Gammarus fossarum increased from an initial concentration of 0.32 to 12.36 ng.g-1 ww (wet weight) at the end of accumulation step. When gammarids were transferred into a clean media, the PCB153 concentration in organisms decreased to 6.41 ng.g-1 ww at day 14. The bioaccumulation model assuming first-order kinetics was fitted to the data using Bayesian inference. The inference process quickly converged and thin posterior distributions were obtained for each parameter, meaning that data brough enough information to estimate preciselly each parameter. The median model predictions and their 95% credibility intervals showed a good fit of the model to the data.
(pp. 1, 01/09/2026)
IRSTEA, LBBE, UCBL, VAS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Seasonal variations of contamination and exoskeletal malformations in the white shrimps Palaemon longirostris in the Gironde estuary, France
Since the end of the 1980s, white shrimps (Palaemon longirostris) from the Gironde estuary have exhibited exoskeletal malformations, mainly involving cephalothorax, rostrum, scaphocerites and uropods. An 8-month study was carried out in 2015. Each month, 200 individuals were sampled and examined for exoskeletal malformations. Temporal variations in malformationfrequency were noted,particularlyduringthebreedingperiod, along withdecreases in the sizeof non-deformedshrimps related to the appearance of juveniles in breeding sites, and high mortality among deformed shrimps. A significant increase in proportions of deformed shrimp was observed, relating particularly to the size (and therefore the age) of individuals. No significant difference was found between shrimp proportions with different numbers of malformations (one to four) for a fixed size class, nor was there any variation in proportions within different size classes for a fixed number of malformations. This would appear toindicate thatthe number ofmalformations isacquiredand new malformations donot seemto appearduringthe lifecycle,exceptforthesmallest(youngest)shrimps.Themalformationspectrumshowednosignificantdifferencesbetweenthe biggest and smallest individuals for the different malformation associations, except for those involving cephalothorax, rostrum and uropods. This would suggest that some malformation associations lead to a higher mortality rate in shrimps subjected to them, due to greater impairment of feeding and/or swimming behaviour. Multiple component analysis of the different types of malformation showed correlations between exoskeletal pieces (rostrum and cephalothorax) and appendixes (scaphocerites and uropods). Regarding metal contamination in shrimp, no significant difference was highlighted between deformed and nondeformed shrimps. Organic pollutants were not measured in tissues. Certain herbicides such as metolachlore and chlortoluron.
(Environmental Science and Pollution Research. vol. 25, n° 0944-1344, pp. 22689-22701, 01/09/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Modifications physiques du littoral
(pp. 305-329, 01/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SIAME, UPPA, LIENSs, INSU - CNRS, ULR, CNRS, UR ETBX, IRSTEA
Quantitative biostratigraphical ranges of some late Cenozoic species of the dinoflagellate genusSpiniferitesand taxonomic considerations
A new quantitative biostratigraphical method, based on an ‘index of stratigraphical abundance’ (ISA), has been used to refine the stratigraphical range of 50 dinoflagellate cyst taxa. Most of these correspond to Quaternary representatives of Achomosphaera or Spiniferites. Some extinct taxa are also discussed when their morphology is close to that of recent species (e.g. Spiniferites lenzii, S. twistringiensis and S. pseudofurcatus), as well as some species possibly related to the motile Gonyaulax spinifera complex. The ISAs of S. mirabilis and S. hyperacanthus are similar, as well as for S. elongatus and S. sphaericum. Although initially presumed as indicating morphotypes of a same taxon, it seems rather that the ISAs similarites must be interpreted as an indication of close ecological preferences. The emergence of forms of Spiniferites with low to absent septa appears relatively late (compared to the range of the genus), but the first occurrence of intergonal processes is relatively early, indicating that it is probably a character deeply rooted into the generic genome. The previously calculated phylogeny of some Gonyaulax motile cells shows a different tree pattern than the stratigraphical first appearance succession of their presumed cyst equivalents.
(Palynology. vol. 42, n° 0191-6122, pp. 203-220, 01/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Contamination of soils by metals and organic micropollutants: case study of the Parisian conurbation
Soils are playing a central role in the transfer and accumulation of anthropogenic pollutants in urbanized regions. Hence, this study aimed at examining the contamination levels of selected soils collected within and around the Paris conurbation (France). This also evaluated factors controlling contamination. Twenty-three trace and major elements as well as 82 organic micropollutants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), phthalates (PAEs), polybrominated diphenyl ethers (PBDEs), alkylphenols (APs), and perfluoroalkylated substances (PFASs) were analyzed. Results reinforced the concern raised by the occurrence and levels of metals such as Zn, Pb, Cu, and Hg, identified as metallic markers of anthropogenic activities, but also pointed out the ubiquitous contamination of soils by organic micropollutants in the 0.2–55,000-μg/kg dw range. For well-documented compounds like PAHs, PCBs, and to a lesser extent PBDEs, contents were in the range of background levels worldwide. The pollutant stock in tested soil was compared to the annual atmospheric input. For PAHs; Pb; and to a lesser extent Zn, Cu, Cd, Hg, Sb, PAEs, and APs, a significant stock was observed, far more important than the recent annual atmospheric fluxes. This resulted from both (i) the persistence of a fraction of pollutants in surface soils and (ii) the cumulative atmospheric inputs over several decades. Regarding PBDEs and PFASs, stronger atmospheric input contributions were observed, thereby highlighting their recent dispersal into the environment.
(Environmental Science and Pollution Research. vol. 25, n° 0944-1344, pp. 23559–23573, 01/09/2026)
LEESU, ENPC, UPEC UP12, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEDI, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, METIS, UPMC, EPHE, PSL, CNRS, EPHE, PSL, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Migrations néandertaliennes et variations climatiques pendant le Saalien supérieur. Apport des modélisations analogiques en enceintes thermo-regulées
(pp. 23-24, 01/09/2026)
CReAAH, UM, UR, UR2, CNRS, UFR HHAA, UN, MC, NSU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Multi-decadal to centennial hydro-climate variability and linkage to solar forcing in the Western Mediterranean during the last 1000 years
Here we present a new composite record from two well-dated speleothem records from two caves in Northern Morocco. The high-resolution record covers the last millennium allowing to detect multi-decadal to centennial periodicities. Over the industrial period, δ18O values of our speleothems are shown to be dominated by the main mode of decadal variability in the North Atlantic region: the North Atlantic Oscillation (NAO). Statistical analyses confirm the previously reported multi-decadal variability related to the influence of the Atlantic Multidecadal Oscillation (AMO) in the region. High power and persistent centennial-scale periodicities, similar to the Vries-Suess 200-year solar cycle, are observed as well. Indeed, comparison between solar activity reconstructions and our record confirms the in-phase relationship on centennial time-scales. Low δ18O values, and hence negative phases of NAO that bring precipitation towards the Western Mediterranean, are observed during well-known solar minima periods. The results are consistent with previous models which describe low irradiance as a trigger for southward shifts of precipitation-bearing westerlies during winter.
(Scientific Reports. vol. 8, n° 2045-2322, pp. 17446, 01/09/2026)
Xjtu, MPIC, USP, LOCEAN-VALCO, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, JGU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMN, UMN