Distribution of the organic matter in the channel-levees systems of the Congo mud-rich deep-sea fan (West Africa). Implication for deep offshore petroleum source rocks and global carbon cycle
The Corinth Rift is superimposed on the Hellenic nappe stack that formed at the expense of the Apulian continental crust above the subducting African slab. Extension started in the Pliocene and the major steep normal faults that control the geometry of the present-day rift were born very recently, some 600 kyr ago only. They root into a shallow-dipping zone of microseismicity recorded near the base of the upper crust. The significance of this seismogenic zone is debated. Considering the northward dip of the zone of microseismicity, the depth of microearthquakes and their focal mechanisms, we observe a strong similarity with the northern Cycladic detachments in terms of expected pressure, temperature conditions and kinematics. We herein show (1) that the formation of the Corinth Rift can be considered a part of a continuum of extension that started some 30–35 Ma in the Aegean and that was recently localised in a more restricted area, (2) that the present-day structure and kinematics of the Corinth Rift can be explained with a series of decollements relayed by steeper ramps that altogether formed a mechanically weak, crustal-scale detachment, and (3) that the deformation, fluid behaviour and metamorphic features seen in the northern Cycladic metamorphic core complexes can be good analogues of the processes at work below the Corinth Rift.
(Marine and Petroleum Geology. vol. 27, n° 0264-8172, pp. 995–1010, 24/02/2026)
iSTeP, UPMC, CNRS, ISTO, INSU - CNRS, UO, UT, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GM, IFREMER
Modélisation physique de la morphodynamique d'une plage barrée tridimensionnelle
Des expériences dans un bassin de 30 m x 30 m ont été réalisées dans l'objectif de caractériser la dynamique d'un courant d'arrachement et les évolutions morphologiques associées. La plage de sable fin (diamètre médian 166 microns) couvrait la largeur du bassin (30 m en longshore ) pour un profil total de 20 m cross-shore . La formation de courants sagittaux a été forcée par une houle frontale (spectre de Jonswap) avec un déficit d'énergie au centre du bassin. Une séquence accrétive complète de plage intermédiaire à simple barre (selon classification de WRIGHT & SHORT, 1984) a été reproduite. La barre s'est progressivement tridimensionnalisée en forme de croissant puis s'est connectée au haut de plage avec la présence de deux chenaux profonds qui se sont ensuite comblés pour obtenir une plage à terrasse au bout de plusieurs dizaines d'heures. L'association des mesures hydrodynamiques et morphodynamiques montre que le comblement des chenaux est alimenté par le haut de plage.
(pp. 45, 24/02/2026)
LEGI, UJF, Grenoble INP, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UAG, INSU - CNRS, UM, CNRS, UQAR, LSEET, INSU - CNRS, UTLN, CNRS
Effect of dietary cadmium on lipid metabolism and storage of aquatic bird Carina moschata
In environment, birds often fast in connection with breeding, migration or drastic climatic conditions and need to mobilize lipid reserves during these periods. The impairment of lipid metabolism by cadmium (Cd; 1 mg kg(-1) added in diet) was investigated on palmiped Cairina moschata. Expression levels of genes involved in lipid metabolism, mitochondrial metabolism and detoxification were investigated in liver and muscle of ducks. Lipid content in muscle and liver were analysed and plasma triglycerides were quantified. After 20 days, ducks exposed to Cd displayed a lower body weight and lower lipid content in liver than controls. In muscle, the increase of lipid content was only significant for control ducks but not for exposed ducks. Exposed ducks appeared unable to sufficiently transport and store lipids into peripheral tissues. Cd impairs lipid metabolism by several ways. First, Cd triggered the down-regulation of fatty acids synthesis in liver even if the NADPH production and the mitochondrial metabolism are enhanced, suggesting a stronger energy needs. Secondly, the associated decrease of plasma triglycerides and lipoprotein lipase activity with Cd are consistent with impairment of lipids storage in peripheral tissues.
(Ecotoxicology, n° 0963-9292, pp. 163-170, 24/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UEPFG, INRA, IPREM, UPPA, INC-CNRS, CNRS
Recovery potential of periphytic biofilm exposed to industrial contamination: field and experimental studies
This study was conducted in a context of impacted hydrosystem remediation in France. The Gironde fluvio-estuarine system has been subjected to polymetallic pollution (Cadmium and Zinc) for over a century, coming from an industrial site specialized in zinc ore treatment carrying contaminated wastes into a small tributary, located about 400 km upstream from the estuary. Since 2007 a major remediation phase has been initiated in the industrial site. This study aims to assess first biological modifications due to remediation procedure on periphytic diatoms biofilms, dominant primary producers in freshwaters. Therefore a yearly biomonitoring of the contamination was conducted in situ through 24 days colonizations cycles along the pollution gradient. The experiments were renewed every 48 days during a year. Glass slides were exposed in three stations located upstream the industrial site and one station dowstream the factory (Joany). After 24 days of colonization the glass slides were scraped to collect biofilm. Different tests were then performed: analyses of metal bioaccumulation, taxonomic investigations, numerations of diatom densities and biomass, and Chlorophyll a concentrations, completed by physicochemical measurements in water. Cadmium and zinc bioaccumulation concentrations were discriminating factors for biofilms from Joany, reaching maximum concentrations in dry weights (DW) of 861 ± 387 μg Cd.g-1 and 21 256 ± 5 701 μg Zn.g-1. Joany biofilms presented high densities too and low BDI values in comparison with the three other stations of colonization, located upstream the industrial site probably in relation with the important nutrients concentrations at this station due to urban wastewaters. Moreover, special attention was devoted to abnormal forms in the taxonomic investigations as it is established in the literature that contaminants promote abnormal forms frequencies. Maximum abnormality rate was observed in biofilms from Joany with 12, value significantly higher compared to biofilm from the 3 other stations below 5. Consequently, initial results show yet a persistence of metallic contamination in situ and high bioaccumulation in biofilms located dowstream industrial site. However, remediation is already perceivable in comparison with previous studies in which bioaccumulation (DW) reached 1809 ± 200 μg Cd.g-1 and 23 750 ± 2 469μg Zn.g-1 after 24 days of colonization at Joany in August 2004. Regarding the frequency of abnormal forms, it remains in the same order of magnitude of 10 to 20 at Joany according to this previous study . To understand in a detailed and integrated way whether the periphytic biofilm can initiate total or partial recovery, laboratory decontamination experiments free of environmental variations have thus been developped. The aim was to characterize the kinetics of biofilm recovery under controlled conditions after in situ and artificial expositions to Cd and Zn following the same analysis criteria than used for in situ experiments. Firsts results have shown a rapid decrease of metallic bioaccumulation with a return to control concentrations after 14 days under recovery conditions. This kind of results suggests the resurgence of sensitive species and the decrease of abnormal forms frequencies and put out diatom biofilm as an appropriate model to reveal effective recovery of polluted freshwater ecosystems.
(pp. 2, 24/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR REBX, CEMAGREF
Abrupt climate changes of the last deglaciation detected in a Western Mediterranean forest record
Abrupt changes in Western Mediterranean climate during the last deglaciation (20 to 6 cal ka BP) are detected in marine core MD95-2043 (Alboran Sea) through the investigation of high-resolution pollen data and pollen-based climate reconstructions by the modern analogue technique (MAT) for annual precipitation (Pann) and mean temperatures of the coldest and warmest months (MTCO and MTWA). Changes in temperate Mediterranean forest development and composition and MAT reconstructions indicate major climatic shifts with parallel temperature and precipitation changes at the onsets of Heinrich stadial 1 (equivalent to the Oldest Dryas), the Bölling-Allerød (BA), and the Younger Dryas (YD). Multi-centennial-scale oscillations in forest development occurred throughout the BA, YD, and early Holocene. Shifts in vegetation composition and (Pann reconstructions indicate that forest declines occurred during dry, and generally cool, episodes centred at 14.0, 13.3, 12.9, 11.8, 10.7, 10.1, 9.2, 8.3 and 7.4 cal ka BP. The forest record also suggests multiple, low-amplitude Preboreal (PB) climate oscillations, and a marked increase in moisture availability for forest development at the end of the PB at 10.6 cal ka BP. Dry atmospheric conditions in the Western Mediterranean occurred in phase with Lateglacial events of high-latitude cooling including GI-1d (Older Dryas), GI-1b (Intra-Allerød Cold Period) and GS-1 (YD), and during Holocene events associated with high-latitude cooling, meltwater pulses and N. Atlantic ice-rafting. A possible climatic mechanism for the recurrence of dry intervals and an opposed regional precipitation pattern with respect to Western-central Europe relates to the dynamics of the westerlies and the prevalence of atmospheric blocking highs. Comparison of radiocarbon and ice-core ages for well-defined climatic transitions in the forest record suggests possible enhancement of marine reservoir ages in the Alboran Sea by 200 years (surface water age 600 years) during the Lateglacial.
(Climate of the Past. vol. 6, n° 1814-9324, pp. 245-264, 24/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EPHE, PSL, LCE, CNRS, UFC, UBFC
Deciphering of six blocks of Gondwanan origin within Eastern Indonesia (South East Asia)
The French Indonesian research programs, both conducted on land and offshore in the Banda Sea basins area, have led us to formulate a new interpretation of the East Indonesian geological components. In this area we distinguish, within the three main tectonic plates (Eurasian, Indo-Australian and Philippine-Pacific), seven blocks. Six blocks are deciphered as issued from the north-eastern Gondwanan margin and only one (the Halmahera block) issued from the Pacific plate. Among the Gondwanan blocks, two of them, namely Timor (probably originates from "Greater India") and Kolonodale (or the Argo block) came from the north-west Australian margin. The Lucipara, Seram and Banggai-Sula blocks originated from the western extension of the Papua-New Guinea Island while the Irian Jaya block is still linked to the North Australian margin. The last one, the Halmahera block, originated from the Pacific plate, moved westward along the North Papua-New-Guinea margin up to its present position in the northern part of the Banda Sea area. Our interpretation is mainly based on the lithostratigraphic succession, the geological evolution and the Early Mesozoic paleoposition of these blocks with respect to the climatic environment deduced from micropaleontological studies. According to previous studies, the Timor and Kolonodale blocks were detached from Gondwana during the Jurassic whereas the Lucipara, Seram and Banggai-Sula blocks were detached from Papua-New Guinea Island during the Neogene period. All these Gondwanan blocks collided with the Eurasian active margin, in the vicinity of Sulawesi Island: Timor and Kolonodale had joined the Eurasian margin by the end of the Paleogene, while Lucipara, Seram and Banggai-Sula collided with Sulawesi Island between the Middle Miocene to Middle Pliocene. After the collisions the last three blocks together with the Kolonodale block did not move again but suffered the opening of North and South Banda back-arc basins, by the Late Miocene. On the contrary, part of the Timor block moved south together with the southern margin of the south Banda basin and, later on during the middle Pliocene, collided with the northern Australian margin. The detachment of these blocks from the Gondwana margin, and their amalgamation with the Eurasian margin, are discussed and illustrated through palaeogeographic maps.
(Gondwana Research. vol. 18, n° 1342-937X, pp. 420-437, 24/02/2026)
FRE 2761, CNRS, UNIGE, LDO, INSU - CNRS, UBO EPE, CNRS, PEPS, UCBL, INSU - CNRS, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, Unhas, ISTO, INSU - CNRS, UO, UT, CNRS, iSTeP, UPMC, CNRS, LPGN, UN, CNRS
How life history contributes to stress response in the Manila clam Ruditapes philippinarum
Introduction Within the last decade, numerous studies have investigated the role of environmental history on tolerance to stress of many organisms. This study aims to assess if Manila clams Ruditapes philippinarum may react differently to cadmium exposure and trematode parasite infection (Himasthla elongata) depending on their origin and environmental history in Arcachon Bay (France). Materials and methods Clams were exposed to Cd (15 µg L−1) and parasites (25 cercariae per clam), alone or in combination, at 15°C under controlled laboratory conditions for 7 days. Metal accumulation and success of parasite infestation were examined, also physiological parameters such as metallothionein response and hemocyte counts and activities (phagocytosis, oxidative burst, viability, and adhesion). Results and Discussion Sensitivity of Manila clams to both stressors differed from one site to another, suggesting local adaptation of populations. Clams from the more parasitized site presented better resistance to trematodes than the others in terms of first line defense, i.e., avoidance of infection. On the other hand, clams that adapted to chronic Cd contamination showed better detoxification mechanisms, both in a faster transfer of metal from gills to visceral mass and in a higher metallothionein baseline, than clams which had never experienced Cd contamination. Finally, hemocyte concentration and viability differed between clam origin site, highlighting the fact that populations living in different environments may adapt their physiological and biochemical responses to environmental stressors. Conclusion It is therefore important to be cautious when extrapolating results from field studies of one species and one site, if the life history of the organisms is not taken into account.
(Environmental Science and Pollution Research. vol. 17, n° 0944-1344, pp. 987-998, 24/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEMAR, IRD, IFREMER, UBO EPE, CNRS
THE EXTENSION OF ID11 FOR NANOSCALE AND HIERARCHICAL CHARACTERIZATION
Beamline ID11 at the ESRF has been recently upgraded by the complete redesign of the optics and by the extension of the beamline to 100 m in length. This has been coupled with the construction of a dedicated endstation for micro- and nano-focusing applications for diffraction and microscopy experiments in solid state chemistry, physics and materials science. Parallel detector schemes allow simultaneous characterization of samples over many length scales and throughout a multi-dimensional parameter space. We report the current ID11 scientific and technical status and the ongoing evolution.
(pp. 457-476, 24/02/2026)
ESRF, CEMHTI, UO, INC-CNRS, CNRS, LCND, LMA, AMU, ECM, CNRS, MATEIS, UCBL, INSA Lyon, INSA, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, DTU
Holocene Antarctic climate variability from ice and marine sediment cores: Insights on ocean–atmosphere interaction
Holocene climate variability in the southeast Atlantic sector of the Southern Ocean and Antarctic is assessed and quantified through integration of available marine sediment core and Antarctic ice core data. We use summer sea surface temperature (SSST) and sea ice presence (SIP) reconstructions from two marine sediment cores recovered north (50 S) and south (53.2 S) of the present day Antarctic Polar Front (APF), as well as an atmospheric temperature and sea ice proxy from the EPICA ice core from Dronning Maud Land (EDML). We find reasonably good agreement in the timing of climate evolution in the analyzed series. Almost all records show a gradual glacial-to-Holocene climate transition, interrupted by the Antarctic cold reversal around 13 000 cal yr BP, and early Holocene climatic optimum (HCO) at about 11 000 cal yr BP. During the early HCO, the seasonal ice cover retreats to south of 53 S; it then readvances in the course of the mid-to late Holocene. The maximum winter sea ice edge position during the recent 10 000 years varied mainly within 51-53 S, with sporadic growth to north of 50 S, a position similar to that during the last glacial. The onset of the Neoglacial period after ca 4000 yr BP is associated with a steepening of the SSST gradient between the marine core sites, strengthening of the westerlies and cooling in the inland ice sheet. The agreement in timing between elevated SSST during the early HCO and decreased deuterium excess in EDML and other ice cores from different locations in the East Antarctic suggests that the retreat of sea ice during the early HCO and weakening of the APF was a general feature of the East Antarctic climate during that time.
(Quaternary Science Reviews. vol. 29, n° 0277-3791, pp. 303-312, 24/02/2026)
UiT, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Behavioral responses of Crassostrea gigas exposed to the harmful algae Alexandrium minutum
We describe the valve-activity behavior of oysters, Crassostrea gigas, exposed experimentally to the harmful alga Alexandrium minutum (≈ 3500 cell ml− 1) for 7-day periods under laboratory conditions. Our aim was to assess behavioral responses of oyster species during a mimicked bloom exposure. We determined different characteristic parameters of valve activity, such as daily valve opening duration, daily number of micro-closures, and valve-opening amplitude using a High Frequency-Non Invasive valvometer. In comparison with oysters exposed to non-toxic algae, T-Isochrysis or Heterocapsa triquetra, the valve activity of C. gigas is measurably different when exposed to toxic algae A. minutum. Surprisingly, daily valve-opening duration increased, as well as micro-closure activity, while valve-opening amplitude decreased. The response to A. minutum is fast, within 1 h after algae exposure. Following A. minutum exposure, recovery to control patterns was observed within 4-5 days. The behavioral alterations upon exposure to A. minutum can be thus used as a complementary physiological variable to other well-established physiological and biochemical measurements.
(Aquaculture. vol. 298, n° 0044-8486, pp. 338-345, 24/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEMAR, IRD, IFREMER, UBO EPE, CNRS