During the SARDINIA experiment, three coincident MCS reflection and wide-angle seismic profiles, sub-bottom high resolution (CHIRP) profiles, and bathymetry data were collected on the Gulf of Lion margin. The seismic reflection data were acquired using a 4.5 km, 360 trace digital streamer and a tuned airgun array of 8260 in3, towed at a depth of 18-28 m. A total of 57 ocean bottom seismometer/ hydrophones (OBS/OBH) from Ifremer, University of Brest, and Geomar Kiel were deployed in the Gulf of Lion, spaced every 7 Nm (~13 km). The airgun array consists of 16 airguns ranging from 100 in3 G-guns to 16 L Bolt airguns, with main frequencies centered around 10-15 Hz. The airguns were tuned to the first bubble to enhance low frequencies and ensure a good penetration. The shot interval was 60 s at an average speed of 5 knots, which translates to a trace spacing of about 140-150 m. The sample rate was 8 ms for the micrOBS, 5 ms for the Geomar’s OBS and 4 ms for the OldOBS. A total of 6160 shots (profile AB: 3032, profile CD: 1730, profile EF: 1398) were fired by the air gun array. Profile AB crosses the Gulf of Lion’s margin, parallel to the ECORS profile, from the continental shelf to Domain III. Twenty-five ocean bottom seismometers (OBS) were deployed on this profile, of 467 km in length. Twenty-two instruments were used in the wide-angle modelling, since three instruments (OBS 45, 49 and 52) did not properly record. The shots on this profile were additionally recorded by 9 land seismic stations (OSIRIS stations from the University of Brest and Geosciences Azur) that have extended the marine profile ~120 km onshore. Profiles CD and EF are 250 and 210 km long transects parallel to the margin. Profile CD was acquired using 19 OBS of which 18 yielded usable data. Profile EF was acquired using 15 OBS of which 12 yielded usable data. These two profiles cross the profile AB, respectivelyat OBS 26  and OBS 8.

210Pb, 226Ra and 137Cs were measured by non-destructive gamma spectrometry on marine sediment cores, collected during RIKEAU 2002 cruise on board r/v Thalia, on the shelf of the Bay of Biscay

Marine microfossils (dinoflagellate cysts and planktonic foraminifera) and geochemical (XRF-Ti/Ca)-based climatic records from a core located off the Fleuve Manche (FM) paleo-mouth (MD13-3438) have revealed that sustained warm summer sea surface temperatures (SSTs) during sub-millennial climate changes within HS1 (~18–14.7 ka) may have played a key role in the FM regime related to the European Ice Sheet (EIS) melting rate. In this study, we have analyzed the MD13-3438 pollen content over the HS1 at a mean resolution of ~50 years to test whether vegetation-based air temperatures were coupled to SSTs face to this rapid climate variability. First, our results highlight two major phases of pollen sources at site MD13-3438, preventing the pollen record to be interpreted as a continuous record of the evolution of vegetation and climate occupying a single watershed across HS1. The first phase, i.e. the HS1-a interval (~18–16.8 ka), is marked by strong occurrences of boreal pollen taxa (especially Picea-Abies). Considering their spatial distribution and the coalescence of the British and Scandinavian ice sheets into the North Sea during the Last Glacial Maximum, these taxa probably originated from the North European Plain, i.e., eastern FM tributaries (east of the Rhine River), where cool-humid conditions generally prevailed. Then, the second phase, i.e. the HS1-b interval (~16.8–14.7 ka BP), is characterized by a deceleration of the EIS retreat and the drop of boreal pollen values at site MD13-3438 further signing a less influence of the upstream FM drainage system and thus a better characterization of pollen sources related with western FM tributaries. Superimposed to these two HS1 main phases, pollen fluctuations are concomitant with sub-millennial variability in the EIS deglaciation intensity. During the early HS1 (HS1-a), we discussed two short-term increases in the ratio between deciduous trees (Quercus-Corylus-Alnus) and herbaceous plants (Plantago-Amaranthaceae-Artemisia). These events were coeval with phases of increasing FM meltwater runoff and SST seasonality (i.e., dinocyst-based summer SST amplification). We associated these events with lower contribution of the upstream FM catchment as well as, possibly, atmospheric warming and regional sea-level positive oscillations. The HS1-b is composed of three main phases that appear more influenced by the downstream FM drainage system. HS1-b1 (16.8–16.3 ka BP) corresponds to the driest and coldest conditions west of the Rhine River. HS1-b2 (16.3–15.6 ka BP) is coeval with large arrivals of iceberg from the Hudson strait in the Bay of Biscay and thus likely to a major sea-level positive oscillation associated with a phase of FM valley reworking. HS1-b3 (15.6–14.7 ka BP) corresponds to persistent arid conditions that preceded the subsequent more humid conditions recorded from 14.7 ka BP at the start of the Bölling-Alleröd.

This dataset gathers isotopic ratios (carbon and nitrogen) and concentrations of both priority (mercury species and polychlorinated biphenyls congeners) and emerging (musks and sunscreens) micropollutants measured in a host-parasite couple (hake Merluccius merluccius muscle and in its parasite Anisakis sp) from the south of Bay of Biscay in 2018. In addition, the hake infection degree measured as the number of Anisakis sp. larvae was added for each hake collected.

The precise location and geometry of oceanic spreading centers and associated transform faults or discontinuities' boundary has fundamental implications in our understanding of oceanic accretion, the accommodation of deformation around rigid lithospheric blocks, and the distribution of magmatic and volcanic processes. The now widely used location of mid oceanic ridges worldwide, published by P. Bird in 2003, can be updated based on recent publicly available and published ship-based multibeam swath bathymetry data (100-m resolution or better), now available to ~25% of the ocean seafloor, but covering a significant proportion of the mid-ocean ridge system (>70%). Here we publish the MAPRIDGES database built under the coordination of CGMW (Commission for the Geological Map of the World), with a first version V1.0 (06/2024) that provides high resolution and up-to-date datasets of mid-ocean ridge segments and associated transform faults, and follow-up updates that will also include non-transform offsets. The detailed mapping of individual mid oceanic ridge segments was conducted using GMRT (Ryan et al., 2009) (version 4.2 for MAPRIDGES V1.0), other publicly available datasets (e.g., NCEI, Pangaea, AWI), and existing literature. MAPRIDGES will be revised with the acquisition of additional datasets, new publications, and correction of any errors in the database. The MAPRIDGE database was built in a GIS environment, where each feature holds several attributes specific to the dataset. We include three different georeferenced shapefile layers: 1) Ridge Segments, 2) Transform Faults, and 3) Transform Zones. The latest corresponds to zones of distributed strike-slip deformation that lack a well-defined fault localizing strain, but that are often treated as transform faults. 1) The Ridge Segments Layer contains 1461 segments with 9 attributes: - AREA_LOCA: The Name of the Ridge System - LOC_SHORT: The short form of the Ridge System using 3 characters - LAT: The maximum latitude of the ridge segment - LONG: the maximum longitude of the ridge segment - LENGTH: the length of the ridge segment in meters - CONFIDENCE: the degree of confidence on digitization based on the availability of high-resolution bathymetry data: 1 = low to medium confidence, 2 = high confidence - REFERENCES: supporting references used for the digitization - NAME_CODE: unique segment code constructed from the LOC_SHORT and LAT attributes in degree, minute, second coordinate format - NAME_LIT: name of the segment from the literature if it exists 2) The Transform Fault Layer contains 260 segments with 4 attributes: - NAME_TF: Name of the transform fault according to the literature - LENGTH: length of the transform fault in meters - LAT: The maximum latitude of the fault segment - LONG: the maximum longitude of the fault segment 3) The Transform Zone layer contains 10 segments with 4 attributes: - NAME_TF: Name of the transform zone according to the literature - LENGTH: length of the transform fault in meters - LAT: The maximum latitude of the fault segment - LONG: the maximum longitude of the fault segment To facilitate revisions and updates of the database, relevant information, corrections, or data could be sent to B. Sautter (benjamin.sautter@univ-ubs.fr) and J. Escartín (escartin@geologie.ens.fr).

The Western Mediterranean Sea is a natural laboratory to address questions about the formation and evolution of continental margins and the relationship between surface and deep processes. The evaporites deposited during the late Miocene’s Messinian Salinity Crisis (MSC) strongly impact its sedimentological and geomorphological evolution. Hereafter, we present a compilation of some of the main regional seismic stratigraphic markers throughout the Western Mediterranean Sea. We provide in xyz format (z in second twt) the original, not interpolated, points interpretation of the following horizons: i) Acoustic basement, ii) Base and Top of the MSC salt, also known as Mobile Unit (MU), iii) base Pliocene and iv) Seafloor. The available reflection seismic dataset, coming from a collaboration between French, Spanish, Algerian and Italian research institutes, covers most of the Western Mediterranean sub-basins with the exception of the Ligurian Basin. This compilation is currently the most comprehensive and updated available in literature and provides a useful contribution to the scientific community working in sedimentary, tectonics and geodynamics studies in the Western Mediterranean Sea.

The West Gironde Mud Patch (WGMP) is a 420-km2 mud belt in the Bay of Biscay, located 25 km off the mouth of the Gironde estuary. This clay-silt feature of 4 m in thickness extends between 30 and 75m water depth, surrounded by the sands and gravels that cover the North Aquitaine continental shelf. Interface cores were collected during JERICOBent-1 cruise (October 2016; Deflandre (2016) doi.org/10.17600/16010400) along two cross-shelf transects for a total of 9 sites. Each sediment core was carefully extruded every 0.5 cm from the top core to 4 cm and every 1 cm below until the core bottom. The sediment layers were used to determine dry bulk density, grain size and selected radioisotope activities (210Pb, 226Ra, 137Cs, 228Th, K).

In the mid-latitudes of the northeast Atlantic, the study of the upper branch of the AMOC is poorly documented. This study provides a complete record of the glacial, deglacial and Holocene dynamics of the easternmost portion of the upper branch of the AMOC, namely the European Slope Current and its glacial equivalent know as the Glacial Eastern Boundary Current (GEBC). To do so, we use core SU81-44 (~1000 m water depth) from the of southern Bay of Biscay (BoB)  upper slope, .The aim of this study is to reconstruct paleoenvironmental and hydrodynamic changes using a multiproxy approach (i.e. benthic foraminiferal assemblage, grain size proxies, oxygen and carbon stable isotopes, and foraminiferal εNd). During the glacial period and the onset of the deglaciation, our results show that the grain size proxies together with the relative densities of the high-energy indicator species Trifarina angulosa and the low oxygen tolerant Globobulimina spp. showed significant fluctuations. These were concomitant with the main climate changes recognized over this period and with the glacial slope paleoflow reconstruction from the northern BoB. This highlights a strong climatic/oceanographic forcing on the sedimentary characteristics of the region and a prominent forcing by changes in near-bottom flow speed. Our data also provide a new constraint on the strength of the slope current in the region during the late deglaciation and Holocene periods. We observe a reinvigoration of the upper branch of the AMOC during the Bølling-Allerød warming, preceding the abrupt resumption of the deeper branch of the AMOC in the western North Atlantic. This seems to confirm the crucial role of the European Slope Current in deep water formation, as it is the case today. Finally, our data show a progressive weakening of the ESC during the Holocene and we hypothesize a link with the long-term dynamics of the subpolar gyre.

New results acquired in south-Brittany (MD08-3204 CQ core: Bay of Quiberon and VK03-58bis core: south Glénan islands) allow depicting Holocene paleoenvironmental changes from 8.5 ka BP to present through a multi-proxy dataset including sedimentological and palynological data. First, grain-size analyses and AMS-14C dates highlight a common sedimentary history for both study cores. The relative sea level (RSL) slowdown was accompanied by a significant drop of the sedimentation rates between ca. 8.3 and 5.7 ka BP, after being relatively higher at the onset of the Holocene. This interval led to the establishment of a shell-condensed level, identified in core VK03-58bis by the “Turritella layer” and interpreted as a marker for the maximum flooding surface. Palynological data (pollen grains and dinoflagellate cyst assemblages) acquired in core MD08-3204 CQ argue for an amplification of the fluvial influence since 5.7 ka BP; the establishment of the highstand system tract (i.e., mixed marine and fluviatile influences on the platform) then accompanying the slowdown of the RSL rise-rates. On the shelf, the amplification of Anthropogenic Pollen Indicators (API) is then better detected since 4.2 ka BP, not only due to human impact increase but also due to a stronger fluvial influence on the shelf during the Late Holocene. Palynological data, recorded on the 8.5–8.3 ka BP interval along an inshore-offshore gradient, also demonstrate the complexity of the palynological signal such as i) the fluvial influence that promotes some pollinic taxa (i.e., Corylus, Alnus) from proximal areas and ii) the macro-regionalization of palynomorph sources in distal cores. In addition, the comparison of palynological tracers, including API, over the last 7 kyrs, with south-Brittany coastal and mid-shelf sites subjected to northern vs. southern Loire catchment areas, allowed discussing a major hydro-climatic effect on the reconstructed palynological signals. Strengthened subpolar gyre dynamics (SPG), combined with recurrent positive North Atlantic Oscillation (NAO) configurations, appear responsible for increased winter precipitations and fluvial discharges over northern Europe, such as in Brittany. Conversely, weakened SPG intervals, associated with negative NAO-like modes, are characterized by intensified winter fluvial discharges over southern Europe. Interestingly, we record, at an infra-orbital timescale, major peaks of API during periods of strengthened (/weakened) SPG dynamics in sites subjects to Brittany watersheds (/Loire watersheds) inputs.

The Mediterranean Sea is generally described as an oligotrophic area where primary productivity is limited to a few coastal environments with nutrient-enriched fluvial input. However, several studies have revealed that the hydrology of the western Mediterranean has major seasonal productive patterns linked either to significant riverine input or to seasonal upwelling cells. This study aims to: i) discuss organic microfossils (i.e. pollen and dinoflagellate cyst assemblages, as well as other non-pollen palynomorphs) from two different productive areas of the western Mediterranean Sea, and ii) examine the importance of the interconnections between marine and continental influences responsible for modern palynomorph distributions. Based on 25 samples from the Gulf of Lion (GoL) and Algerian Margin, this study key findings are: i) that GoL marine productivity is driven by the combination of discharges from the Rhône River and seasonal upwelling mechanisms, ii) that the strong productive pattern of the northern African coast is driven by water density front mixings and related upwellings. These two patterns are discussed in the light of major links that provide a better understanding of the signatures of marine and continental bio-indicators. The dinocyst Lingulodinium machaerophorum can be considered as a tracer of Rhône River plume influence in the GoL. Brigantedinium taxa are shown to be upwelling-sensitive in both studied areas. Typical differences in vegetation across the north–south climate gradient in the western Mediterranean Basin are highlighted by the larger ratio of Euro-Siberian to Mediterranean pollen taxa in the northern sector. Synoptic maps also illustrate the complex interactions of environmental drivers determining the distributions of continental and marine palynomorphs in the western Mediterranean Sea.