The Mediterranean Outflow Water (MOW), modified by paleoceanographic conditions and tectonic processes, played a significant role in the formation of sediments drifts along the Iberian Margin. Using sediment samples from IODP Hole U1387C, we explore the Early Pleistocene history of the upper MOW core above the central Faro Drift in the Gulf of Cadiz. The time series of benthic foraminifer stable isotope and grain size related data have a rigorous stratigraphic framework consisting of nannofossil biostratigraphy and paleomagnetic and delta 18O stratigraphy. The paleoenvironmental records are supplemented by natural gamma ray downhole logging data. Above the hiatus associated with the youngest dolostone, sandy to muddy contourite sedimentation started at 1.946 Ma, i.e., within Marine Isotope Stage (MIS) 74, at IODP Site U1387, slightly younger than at IODP Site U1389. Formation of contourite layers, reflected in the sortable silt and sand percentage records, strongly reacted to precession forcing, including semi- and quarter-precession cycles. The majority of the contourite beds developed during stadial (colder) climate periods, like previous observations from the Early to Late Pleistocene. Formation of contourite layers within MIS 53, MIS 55 and MIS 65, however, appear to be linked to the prevailing atmospheric conditions over North Africa. Periods of poor ventilation in the upper MOW were linked to insolation maxima and reduced ventilation in the Mediterranean Sea. Here, MIS 51 presents a peculiar case as poor ventilation reached from the surface to the lower North Atlantic Deep Water range, reflecting unique interglacial conditions that merit future exploration.

The prediction of offshore sedimentary architectures is a first plan approach to the geological study of continental margins. While such work is commonly led using seismic surveys tied to well-logs, we are interested in land-sea objects for which there is no direct tie between seismic signal and lithology. More precisely, we look at shoreline clinoforms and more continental deposits of which size is below used seismic resolution, and their integration at the shelf-scale. The Roussillon Basin’s Pliocene infill satisfies these criteria. It belongs to a progradational land-sea prism about 100km-long, displaying essentially clinothems and defining the Gulf of Lion modern shelf. It is described with high quality conventional seismic profiles offshore, while outcrops and drill-cores are available onshore. However, there is no data at the transition between the two domains. In order to predict the offshore sedimentary architecture, we establish classical equivalence hypotheses between seismic facies and expected associated sedimentary facies. This work is based on the seismic facies interpretation and on the lithologies known from outcrops and onshore drillings. Nonetheless, without directly tied-in seismic such hypotheses rely essentially on interpretation. This, together with seismic data vertical resolution (~15m in thickness) and the upscaling from direct observations onshore, introduce uncertainties. In order to produce more reliable sedimentary predictions, we test our hypotheses through forward seismic modelling using SeisRoX pro by NORSAR. We create small scale geological/impedance models based on onshore sedimentary observations coupled with well-logs petrophysical data (P-wave velocities). Then we simulate acoustic waves propagation through them and obtain theoretical seismic profiles that are subsequently compared to the seismic data. This method, including a geophysical control, allows for the testing of various geological hypothesis at the outcrop-scale, and for a more objective subsurface description. Among the results, we show that vertical velocity variations at a meter scale eventually get a specific seismic signature in terms of both geometry and amplitude on conventional seismic profiles. More generally, we illustrate different lithological models and their results, which allow for a high-resolution reconstruction of most parts of the Roussillon Basin’s Pliocene offshore prism.

We review scientific ocean drilling of the New Jersey passive continental margin and the success of Integrated Ocean Drilling Program (IODP1) Expedition 313 in addressing long-standing, fundamental issues of sequence stratigraphy, sea-level change, and resources. The New Jersey margin was targeted for study by several gener-ations of ocean drilling because of its thick, prograding Oligocene to Quaternary sequences bounded by un-conformities. Coring and logging on the onshore coastal plain (Ocean Drilling Program [ODP] Legs 150Xh ttp://www-odp.tamu.edu/publications/citations/cite150X.htmland 174AX), outer continental shelf (Leg 174A), and continental slope and rise (Legs 95, 150, and 174A) provided a chronology of sea-level lowerings but did not sample facies needed to evaluate Miocene sea-level amplitudes. Expedition 313 used a Mission Specific Platform (L/B Kayd) to drill on the shallow continental shelf, recover critical Miocene facies, particularly on clinoform foresets, and capture the full amplitudes of relative sea-level changes. Expedition 313 overcame challenging borehole conditions and recovered a total of 1311 m of core at three sites (81 % recovery) that: (1) correlated difficult-to-date nearshore-shelf facies to the time scale with resolution better than +/- 0.5 million years (Myr); (2) tested and confirmed that sequence boundaries are a primary cause of seismic reflections on siliciclastic shelves;(3) tested sequence stratigraphic models with core-log-seismic integration; and. (4) provided a record of paleodepth changes through time that constrained amplitudes of Miocene sea-level change, including the influence of mantle dynamic topography. The New Jersey relative sea-level estimates are similar to those obtained using stable isotopes and Mg/Ca paleothermometry, showing that GMGSL ("eustasy") varied with 10-60 m scale amplitudes on the Myr scale. Drilling beneath the shallow continental shelf also identified groundwater sources, including seawater, deep- sourced brines, and meteoric fresh water, that represent potential resources for future generations. Studies of this margin have implications for future subsurface storage of supercritical CO2 and geotechnical issues relating to the location of offshore wind infrastructure. Expedition 313 demonstrated the feasibility of continuously recovering and logging strata in shallow water, providing constraints on sea level, sequences, hydrogeology, and resources

This study predicts sedimentary architectures and facies distribution within the Pliocene prograding prism of the Roussillon Basin (Gulf of Lion, France), developed along an onshore–offshore continuum. Boreholes and outcrops provide facies-scale observations onshore, while seismic data capture basin-scale structures offshore. Forward seismic modeling bridges spatial and scale gaps between these datasets, yielding characteristic synthetic seismic signatures for the sedimentary facies associations observed onshore, used as analogs for offshore deposits. These signatures are then identified in offshore seismic data, allowing seismic profiles to be populated with sedimentary facies without a well tie. Predicted offshore architectures are consistent with shoreline trajectories and facies successions observed onshore. The Roussillon prism records passive margin reconstruction in the Mediterranean Basin following the Messinian Salinity Crisis, through the following three successive depositional profiles marking the onset of infilling: (1) Gilbert deltas, (2) wave- and storm-reworked fan deltas, and (3) a wave-dominated delta. Offshore, transitions in clinoform type modify sedimentary architectures, influenced by inherited Messinian paleotopography. This autogenic control generates spatial variability in accommodation, driving changes in depositional style. Overall, this multi-scale and integrative approach provides a robust framework for predicting offshore sedimentary architectures and can be applied to other deltaic settings with limited land–sea data continuity.

From 2016 to 2020, Judy McKenzie joined the community of COST Action CA15103 - Uncovering the Mediterranean salt giant (MEDSALT) to verify her hypothesis that an ongoing dolomitization front exists in the pelagic sediments overlying Messinian evaporites below the Messina Abyssal Plain, in ~4000 water depth in the Ionian Sea, central Mediterranean. Legacy scientific ocean drilling data from DSDP Leg 42A, Site 374 reveal a 25 m-thick latest Miocene dolomitic mudstone capped by 8.5 m of earliest Pliocene dolomite above gypsum/dolomitic mudstone cycles and anhydrite and salts. The Pliocene dolomite is made of dolomicrite with an unusual crystal morphology, suggesting diagenetic replacement of the original pelagic calcite ooze. The underlying latest Messinian dolomitic mudstone with minor gypsum layers contains Ca-rich dolomite with white spherules of lüneburgite. DSDP Site 374 shipboard interstitial water geochemical profiles further indicate that saline brine is diffusing upwards into the early Pliocene dolomicrite. A significant decrease in sulfate concentration suggests ongoing bacterial sulfate reduction, whereas the chloride profile remains constant.Following discussion and brainstorming with Judy, a geophysical site investigation cruise on the RV Meteor was organized by the University of Hamburg. Cruise M-144 was conducted in 2018 with a multi-channel reflection seismic survey centered at DSDP Leg 42A, Site 374 using a 6 kjoule sparker source and a digital 144-channel streamer with an active length of 600 m. The objectives of the cruise were to:Obtain a detailed seismic stratigraphy in the surrounding of DSDP Leg 42A, Site 374, which was targeted as re-occupation Site within IODP Proposal 857C - The demise of a salt giant: climatic-environmental transition during the terminal Messinian Salinity Crisis (Claudia Bertoni and co-workers); Estimate the lateral dimensions of the combined dolomite/evaporite lithologic units in the lonian Sea. Objective 1 was achieved, and the drilling proposal supported by the R/V Meteor Site Survey was forwarded by the Science Evaluation Panel to the JR Facility Board for scheduling. Unfortunately scheduling could not happen before the end of IODP.Objective 2 was based on the assumption that the acoustic impedance contrasts induced by the dolomitization front could be detected in relatively high-resolution seismic reflection data. In the M-144 data, the uppermost Messinian dolomite- and gypsum-bearing sediments are characterized by a package of strong and positive reflection amplitudes (High Amplitude Reflection Package, HARP). The lateral continuity of the reflections is very low and the upper boundary is quite irregular. Based on the seismic data, the areal extent of the dolomite deposit beneath the lonian abyssal plain can be estimated in a few tens of thousands km2. This would be the Rosengarten of the Ionian Sea that Judy was looking for.This abstract will present previous and new seismic data, collected with Meteor Cruise M-199 in February-March 2024 with similar acquisition parameters to those of M-144, to further address objective 2. However, crucial sedimentological and geochemical data to validate Judy’s fascinating hypothesis can only be derived from new scientific drilling.

The hyper-extended Eastern Sardinian margin is due to the eastward migration of the Appennine-Calabria subduction zone, creating the Neogene back-arc Tyrrhenian Basin. This area was affected by strong erosion during the Messinian Salinity Crisis (MSC, 5.97 - 5.33 Ma) on the continental shelf and slope leading to a major discontinuity, known as the Messinian Erosion Surface (MES), constituting, therefore, a remarkable stratigraphic marker. It is also a powerful paleo-topographic marker of the MSC times and can be used as a marker of the deformation during Plio-Quaternary times. The end of the rifting phase in the Eastern Sardinian margin is dated during the Tortonian (11.63 - 7.25 Ma) attested by the occurrence of a relatively thick syn- and post-rift sequence pre-dating the MES.The “METYSS 4” cruise led to the acquisition of more than 2,000 km of very high-resolution (VHR) seismic reflection data, following a dense grid, on the Eastern Sardinian continental shelf and slope, which has been little explored until now. Seismic interpretation allowed for mapping the major erosion surface, the MES, across the continental shelf and slope. At the base of the PQ sequence, the MSC paleo-topography highlights a hydrographic paleo-network identical to the current one and a general progradation of the shelf-break toward the east during the Plio-Quaternary. In the southern part of the study area, several east-dipping normal faults, oriented N-S, significantly shift the MES (between 5 and 55 m; assuming sound wave velocity of 1700 m/s in Plio-Quaternary sediments). The MES is tilted toward the fault and is covered by Plio-Quaternary deposits, which display a fan-shaped geometry (eg. 50 m thick on the hanging wall). These NS-trend faults are cross-cut by E-W trending messinian canyon and this fault pattern is also observed on the other flank of the canyon. The along-strike geomorphological analysis of canyons reveals the occurrence of knickpoints (slope breaks) coinciding with the front of the two fault patterns. Moreover, the shifts in water depth of most knickpoints are at the same order of amplitude than fault offsets (ie. 10 to 50 m). These geomorphologic markers reinforce the hypothesis that the fault activity is recent (ie. less than 5 Ma). We interpret these observations as markers of a recent reactivation of the structures inherited from the rift in the western part of the Tyrrhenian Sea.

The Sorbas Basin (Spain) has been a key study area for the understanding of the Late Miocene Messinian Salinity Crisis (MSC) (5.97-5.33 Ma). The MSC deposits of the Sorbas Basin consist of four sedimentary units: (1) the pre-MSC Abad marls topped by (2) the evaporitic Yesares gypsum member, followed by two non-evaporitic units known as the (3) Sorbas and (4) Zorreras members. These deposits have been widely studied almost exclusively in the several outcrops across the basin. In 2021, four ~175m-long boreholes (named SG0, 1, 2 and 3) covering most of the MSC sequence were drilled, cored, and logged in the Marylen gypsum mine in Sorbas. These successions provided for the first time a continuous, non-outcropping succession of the MSC record. In addition to the recovered cores (~75% recovery), downhole geophysical logging data was obtained from the four holes and digital images of the area were collected with a drone. Optical borehole wall images provide mm-scale images of the borehole walls, highlighting the sedimentological and structural characteristics of the deposits. Downhole geophysical measurements included acoustic velocity, electric resistivity and magnetic susceptibility, and natural spectral gamma ray. In addition to the petrophysical logs, a Vertical Seismic Profile, including a walk-away distributed acoustic sensing experiment, was acquired in holes SG2 and SG3. Preliminary results confirmed not only the astronomical precession-driven cyclicity observed elsewhere in the Messinian gypsum, but also potentially higher-frequency cyclicity in the post-evaporitic Sorbas Mb. The Digital Outcrop Model allowed for a detailed correlation between the wells while recognizing various discontinuities and obtaining 3D data of geometry and dimensions of the different geobodies that respond to the interaction of auto and allocyclic processes that conditioned erosion and sedimentation in this western sector of the Mediterranean.

From 2016 to 2020, Judy McKenzie joined the community of COST Action CA15103 - Uncovering the Mediterranean salt giant (MEDSALT) to verify her hypothesis that an ongoing dolomitization front exists in the pelagic sediments overlying Messinian evaporites below the Messina Abyssal Plain, in ~4000 water depth in the Ionian Sea, central Mediterranean. Legacy scientific ocean drilling data from DSDP Leg 42A, Site 374 reveal a 25 m-thick latest Miocene dolomitic mudstone capped by 8.5 m of earliest Pliocene dolomite above gypsum/dolomitic mudstone cycles and anhydrite and salts. The Pliocene dolomite is made of dolomicrite with an unusual crystal morphology, suggesting diagenetic replacement of the original pelagic calcite ooze. The underlying latest Messinian dolomitic mudstone with minor gypsum layers contains Ca-rich dolomite with white spherules of lüneburgite. DSDP Site 374 shipboard interstitial water geochemical profiles further indicate that saline brine is diffusing upwards into the early Pliocene dolomicrite. A significant decrease in sulfate concentration suggests ongoing bacterial sulfate reduction, whereas the chloride profile remains constant. Following discussion and brainstorming with Judy, a geophysical site investigation cruise on the RV Meteor was organized by the University of Hamburg. Cruise M-144 was conducted in 2018 with a multi-channel reflection seismic survey centered at DSDP Leg 42A, Site 374 using a 6 kjoule sparker source and a digital 144-channel streamer with an active length of 600 m. The objectives of the cruise were to: Obtain a detailed seismic stratigraphy in the surrounding of DSDP Leg 42A, Site 374, which was targeted as re-occupation Site within IODP Proposal 857C - The demise of a salt giant: climatic-environmental transition during the terminal Messinian Salinity Crisis (Claudia Bertoni and co-workers); Estimate the lateral dimensions of the combined dolomite/evaporite lithologic units in the lonian Sea. Objective 1 was achieved, and the drilling proposal supported by the R/V Meteor Site Survey was forwarded by the Science Evaluation Panel to the JR Facility Board for scheduling. Unfortunately scheduling could not happen before the end of IODP. Objective 2 was based on the assumption that the acoustic impedance contrasts induced by the dolomitization front could be detected in relatively high-resolution seismic reflection data. In the M-144 data, the uppermost Messinian dolomite- and gypsum-bearing sediments are characterized by a package of strong and positive reflection amplitudes (High Amplitude Reflection Package, HARP). The lateral continuity of the reflections is very low and the upper boundary is quite irregular. Based on the seismic data, the areal extent of the dolomite deposit beneath the lonian abyssal plain can be estimated in a few tens of thousands km2. This would be the Rosengarten of the Ionian Sea that Judy was looking for. This abstract will present previous and new seismic data, collected with Meteor Cruise M-199 in February-March 2024 with similar acquisition parameters to those of M-144, to further address objective 2. However, crucial sedimentological and geochemical data to validate Judy’s fascinating hypothesis can only be derived from new scientific drilling.

<p>The Eastern Sardinian margin consists in a hyper-extended rifted margin, located in the western Tyrrhenian Sea, a recent back-arc basin (late Neogene). This area was affected by strong aerial erosion during the Messinian Salinity Crisis (MSC, 5.96 – 5.33 My) associated with the drop of sea level (> 1500 m) which occurred throughout the whole Mediterranean. The Gulf of Orosei and surrounding offshore areas are characterized by small and diffuse drainage systems input, where the Messinian Erosion Surface (MES) has rarely been studied while it has been in large fluvial systems (Rhone, Ebro). The MES was already found in the Cendrino valley (which flows in the Gulf) and in the East-Sardinia Basin but the link between onshore and offshore was never been studied in the area. The “METYSS 4” cruise (June 2019, R/V “Téthys II”) allowed acquiring more than 2000 km of very high-resolution (VHR) seismic data (Sparker), following a dense grid (1.5 km average profile spacing), on the Eastern Sardinian continental shelf, and especially in the Orosei Gulf area, that has been little explored until now. While the main limitation on seismic data (air-gun) interpretation is often due to the occurrence of sea bottom multiple, the limitation for Sparker data may also be due to very short shot intervals at greater water depth. The seismic trace ends where there still is signal of interest. Thus, we applied a simple method to increase investigation depth for short shot intervals (0.333 - 0.533 ms), which allowed interpretation on the continental slope. This approach consists in copying the raw data and concatenating the copied data under the raw data with a shift of 1 shot point. To constrain the MES depth on the continental slope and shelf we compared air-gun seismic data from previous METYSS surveys, where the MES has already been interpreted by a strong erosional discordance between Plio-Quaternary deposits and pre-MSC units, with the new VHR data. The restoration of the morphological features of the Orosei canyon at Messinian times shows that the former Messinian canyon network is very similar to the present-day one. The present-day canyon and its tributaries show sub-marine erosion in the talwegs. The heads of the canyons present gravitational features, highlighted by chaotic deposits near the talweg of the canyon or in-between the Plio-Quaternary strata. Offshore Arbatax, south Orosei, the seismic profiles show no significant Plio-Quaternary deposits (thickness < 0.1 sTWT), which allows polygenic pre-MSC units to occur at the seafloor. In the Gulf, we observe thick deposits (0.4 - 0.5 sTWT) on the right bank of Orosei Canyon, making it more complicated to image the MES in this area. The sedimentation rate on this margin is very low (<em>c.a.</em> 9 cm/ka in the Gulf of Orosei), which is consistent with previous studies on the East-Sardinian basin (3-20 cm/ka). These preliminary results will allow correlating for the first time the MES distribution from the onshore to the offshore continental slope of the Eastern Sardinian Margin in order to improve the MSC understanding in this key area.</p>

The Central Mallorca Depression (CMD) located in the Balearic Promontory (Western Mediterranean) contains a well-preserved evaporitic sequence belonging to the Messinian Salinity Crisis (MSC) salt giant, densely covered by high- and low-resolution seismic reflection data. It has been proposed recently that the MSC evaporitic sequence in the CMD could be a non-deformed analogue of the key MSC area represented by the Caltanissetta Basin in Sicily. This presumed similarity makes the CMD an interesting system to better understand the MSC events. Physics-based box models of the water mixing between sub-basins, built on conservation of mass of water and salt, help constrain the hydrological conditions under which evaporites formed during the MSC. Those models have been widely used in the literature of the MSC in the past two decades. They have been mostly applied to the Mediterranean Sea as a whole focusing on the Mediterranean-Atlantic connection, or focusing on the influence of the Sicily Sill connecting the Western and Eastern Mediterranean Sea. In this study, we apply a downscaled version of such modelling technique to the CMD. First, we quantify the present-day volumes of the MSC units. We then use a reconstructed pre-MSC paleo-bathymetry to model salinity changes as a function of flux exchanges between the CMD and the Mediterranean. We show that a persistent connection between the CMD and the Mediterranean brine near gypsum saturation can explain volume of Primary Lower Gypsum under a sea level similar to the present. For the halite, on the contrary, we show that the observed halite volume cannot be deposited from a connected CMD-Mediterranean scenario, suggesting a drawdown of at least 850 m (sill depth) is necessary. Comparison between the deep basin halite volume and that of the CMD shows that it is possible to obtain the observed halite volume in both basins from a disconnected Mediterranean basin undergoing drawdown, although determining the average salinity of the Western Mediterranean basin at the onset of drawdown requires further investigation.

A new set of physical property measurements was undertaken on 29 peak‐ring samples from the IODP‐ICDP Expedition 364. Among the studied lithologies, the dominant one recovered in the peak ring consists of shocked granitoid rocks (19 samples). Porosity measurements with two independent methods (triple weight and 14 C‐PMMA porosity mapping) concur and bring new observations on the intensity and distribution of fracturing and porosity in these shocked target rocks. Characterization of the porous network is taken a step further with two other independent methods (electrical and permeability measurements). Electrical properties such as the cementation exponent (1.59 < m < 1.87) and the formation factor (21 < F < 103) do not compare with other granites from the published literature; they point at a type of porosity closer to clastic sedimentary rocks than to crystalline rocks. Permeabilities of the granitoid rocks range from 0.1 to 7.1 mD under an effective pressure of ∼10 MPa. Unlike other fresh to deformed and altered granitoid rocks from the literature compared in this study, this permeability appears to be relatively insensitive to increasing stress (up to ∼40 MPa), with implications for the nature of the porous network, again, behaving more like cemented clastic rocks than fractured crystalline rocks. Other analyzed lithologies include suevite and impact melt rocks. Relatively low permeability (10 −3 mD) measured in melt‐rich facies suggest that, at the matrix scale, these lithologies cutting through more permeable peak‐ring granitoid rocks may have been a barrier to fluid flow, with implications for hydrothermal systems.

Note: ɸ-porosity, ρb-bulk density, ρg-grain density, k-permeability, F-formation factor, m-cementation exponent, τ2-tortuosity, Cs-surface conductivity, Vp-acoustic velocity of compressional waves. Uncertainty for porosity, density, permeability, velocity and conductivity is 5%. Uncertainty for formation factor, cementation exponent and tortuosity is 8%). Lith 1 and Unit 1 after Morgan et al. (2017), Unit 2 after de Graaf et al. (2021, UIM-upper impact melt rock unit, LIMB-lower impact melt rock-bearing unit)) and Kaskes et al. (2021). Morgan, J. V., Gulick, S. P. S., Bralower, T. J., Chenot, E., Christeson, G. L., Claeys, P., et al. (2016). The formation of peak rings in large impact craters. Science, 354(6314), 878–882. https://doi.org/10.1126/science.aah6561 de Graaff, S. J., Kaskes, P., Déhais, T., Goderis, S., Vinciane, D., Ross, C. H., et al. (2021). New insights into the formation and emplacement of impact melt rocks within the Chicxulub impact structure, following the 2016 IODP-ICDP Expedition 364. Geological Society of America Bulletin. https://doi.org/doi: https://doi.org/10.1130/B35795.1 Kaskes, P., de Graaff, S. J., Feignon, J. G., Déhais, T., Goderis, S., Ferrière, L., et al. (2021). Formation of the crater suevite sequence from the Chicxulub peak ring: A petrographic, geochemical, and sedimentological characterization. Geological Society of America Bulletin. https://doi.org/https://doi.org/10.1130/B36020.1

More than 80 Mm3per year are pumped into the Roussillon plain coastal aquifer located between the Pyrenean massif to the South and West, and the Mediterranean to the East. This is a 350 m thick Pliocene multilayered aquifer, with sandy layers embedded in low-permeability clayey material and topped by Quaternary alluvial deposits. The groundwater resource is primarily used for drinking water and irrigation. For more than 40 years, this aquifer has been undergoing a piezometric level decline due to pumping, while water demand is expected to increase with ongoing climate change, sea level rise and increasing demand in water use. Consequently, the Roussillon aquifer is likely to suffer from sea water intrusion and marine submersion in the near future. As part of the Dem'Eaux Roussillon project, a set of downhole geophysical profiles was recorded at three drill sites, in Saint Cyprien and Barcares along the Mediterranean shore and at Pollestres, 14 km inland. Downhole petrophysical data (NMR porosity and permeability, acoustic velocities, electrical resistivity and spectral gamma natural radioactivity) contribute to better define the penetrated structure. Core petrophysical measurements were also made to support and calibrate these analyses and, in particular, to provide a dm-scale description of the subsurface pore fluid electrical conductivity along the length of each hole. A combined analysis of the latter with porosity and permeability points at incipient and m-scale intrusion processes along discreate horizons. Repeated downhole measurements overtime and fluid sampling provide a means to follow the dynamics of these intrusion processes found to be more acute at the Barcarès site to the North than close to the Pyrenean, at Saint Cyprien. While high-resolution permanent downhole geophysical observatories have been installed to measure at high frequency both formation electrical resistivity and temperature, a real time management of groundwater resources should contribute to improve aquifer water quality in the future. These observatories datasets will be analyzed and modeled on the basis of smaller scale petrophysical data, providing both an assessment of water quality evolution in terms of salinity from resistivity and quantity in terms of flow rate from temperature.

The Late Miocene deposits in the Sorbas Basin (Spain) have been of an extreme importance in the understanding of the Messinian Salinity Crisis (MSC) events (5.97-5.33 Ma). They consist of four formations. The pre-crisis Abad marls topped by the evaporitic Yesares gypsum member, followed by two non-evaporitic units known as the Sorbas and Zorreras members. Those deposits have been widely explored and studied thanks to the numerous outcropping sections in the basin. The ‘SaltGiant’ European Training Network held a training school in October 2021 in the Sorbas Basin, where four boreholes (named SG0, 1, 2 and 3) covering most of the Messinian Salinity Crisis sequence, were drilled, cored and logged in this context along an overall thickness of about 175 m. The drillings took place inside and in the vicinity of the Torralba gypsum mine. It allowed for the first time in the scientific non-industrial domain, access to a continuous and non-outcropping succession of the Messinian deposits in the Sorbas basin. In addition to the recovered cores, borehole geophysical data were obtained from the four holes and digital images of the area were collected with a drone. Prior to the drilling, an OBO (Outcrop / Behind Outcrop) workflow was followed, which will allow integrating the outcrop and subsurface data by combining the 3D geometry of geobodies with geophysical information. Optical borehole wall images provide mm-scale images of the borehole walls, highlighting the sedimentological and structural characteristics of the deposits. Downhole geophysical measurements included acoustic velocity, electrical resistivity and natural spectral gamma ray, which allowed determining the petrophysical characteristics of the penetrated lithologies. In addition to the petrophysical logs, a Vertical Seismic Profiling was performed in holes SG2 and SG3, including a multi-offset VSP survey in hole SG3. The petrophysical characterization of the Messinian deposits will provide a reference case study for the lithologic characterization of MSC deposits in the subsurface elsewhere. VSP analysis provided an in-field preliminary seismic velocity evaluation in the encountered formations. Preliminary results confirm the astronomical precession-driven cyclicity observed elsewhere in the Messinian gypsum. Further processing and analyses of the large amount of acquired data will lead to identifying the astronomical and possibly higher-frequency cyclicity in the post-evaporitic deposits in the Sorbas member.

More than 80 Mm3per year are pumped into the Roussillon plain coastal aquifer located between the Pyrenean massif to the South and West, and the Mediterranean to the East. This is a 350 m thick Pliocene multilayered aquifer, with sandy layers embedded in low-permeability clayey material and topped by Quaternary alluvial deposits. The groundwater resource is primarily used for drinking water and irrigation. For more than 40 years, this aquifer has been undergoing a piezometric level decline due to pumping, while water demand is expected to increase with ongoing climate change, sea level rise and increasing demand in water use. Consequently, the Roussillon aquifer is likely to suffer from sea water intrusion and marine submersion in the near future. As part of the Dem'Eaux Roussillon project, a set of downhole geophysical profiles was recorded at three drill sites, in Saint Cyprien and Barcares along the Mediterranean shore and at Pollestres, 14 km inland. Downhole petrophysical data (NMR porosity and permeability, acoustic velocities, electrical resistivity and spectral gamma natural radioactivity) contribute to better define the penetrated structure. Core petrophysical measurements were also made to support and calibrate these analyses and, in particular, to provide a dm-scale description of the subsurface pore fluid electrical conductivity along the length of each hole. A combined analysis of the latter with porosity and permeability points at incipient and m-scale intrusion processes along discreate horizons. Repeated downhole measurements overtime and fluid sampling provide a means to follow the dynamics of these intrusion processes found to be more acute at the Barcarès site to the North than close to the Pyrenean, at Saint Cyprien. While high-resolution permanent downhole geophysical observatories have been installed to measure at high frequency both formation electrical resistivity and temperature, a real time management of groundwater resources should contribute to improve aquifer water quality in the future. These observatories datasets will be analyzed and modeled on the basis of smaller scale petrophysical data, providing both an assessment of water quality evolution in terms of salinity from resistivity and quantity in terms of flow rate from temperature.

The numerous processes (superficial and deep) occurring on margins, their origins, consequences, interactions and quantifications are only very partially described and understood. The identification of the relative role of factors is sometimes completely contradictory between authors. Here, we showed the results of a long-term multidecadal and multidisciplinary study (using geophysical, geological, stratigraphic, paleontological, geomorphologic, geochemical, microbiological and numerical models) in the Western Mediterranean Sea that acts as a natural laboratory at many different scales. We showed how sediments efficiently recorded at the same time: variations of glacio-eustatic sea-level changes, variations of sediments yield and sources, and also enabled quantifying vertical movements and geodynamic worldwide events but also detailed regional mass transport, turbidites and contourites deposits. They are also an archive of paleoclimatic, palaeoceanographic and diagenetic processes.

The MagellanPlus workshop “BlackGate” addressed fundamental questions concerning the dynamic evolution of the Mediterranean–Black Sea (MBS) gateway and its palaeoenvironmental consequences. This gateway drives the Miocene–Quaternary circulation patterns in the Black Sea and governs its present status as the world's largest example of marine anoxia. The exchange history of the MBS gateway is poorly constrained because continuous Pliocene–Quaternary deposits are not exposed on land adjacent to the Black Sea or northern Aegean. Gateway exchange is controlled by climatic (glacio-eustatic-driven sea-level fluctuations) and tectonic processes in the catchment as well as tectonic propagation of the North Anatolian Fault Zone (NAFZ) in the gateway area itself. Changes in connectivity trigger dramatic palaeoenvironmental and biotic turnovers in both the Black Sea and Mediterranean domains. Drilling a Messinian to Holocene transect across the MBS gateway will recover high-amplitude records of continent-scale hydrological changes during glacial–interglacial cycles and allow us to reconstruct marine and freshwater fluxes, biological turnover events, deep biospheric processes, subsurface gradients in primary sedimentary properties, patterns and processes controlling anoxia, chemical perturbations and carbon cycling, growth and propagation of the NAFZ, the timing of land bridges for Africa and/or Asia–Europe mammal migration, and the presence or absence of water exchange during the Messinian salinity crisis. During thorough discussions at the workshop, three key sites were selected for potential drilling using a mission-specific platform (MSP): one on the Turkish margin of the Black Sea (Arkhangelsky Ridge, 400 m b.s.f., metres below the seafloor), one on the southern margin of the Sea of Marmara (North İmrali Basin, 750 m b.s.f.), and one in the Aegean (North Aegean Trough, 650 m b.s.f.). All sites target Quaternary oxic–anoxic marl–sapropel cycles. Plans include recovery of Pliocene lacustrine sediments and mixed marine–brackish Miocene sediments from the Black Sea and the Aegean. MSP drilling is required because the JOIDES Resolution cannot pass under the Bosporus bridges. The wider goals are in line with the aims and scope of the International Ocean Discovery Program (IODP) “2050 Science Framework: Exploring Earth by Scientific Ocean Drilling” and relate specifically to the strategic objectives “Earth's climate system”, “Tipping points in Earth's history”, and “Natural hazards impacting society”.