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Pteropods are holoplanktonic molluscs presently endangered because their fragile aragonitic shell is very sensitive to ocean acidification. The preservation of pteropods, and in particular of the mesopelagic Heliconoides (Limacina) inflatus, has been used to assess aragonite saturation state in Quaternary sediments (Limacina Dissolution Index, LDX) as an inferred proxy for climatic changes. Three deep-sea cores retrieved in 2016 during the EUROFLEETS2 SEMSEEP cruise offshore Israel are investigated to assess the preservation degree of H. inflatus (d'Orbigny, 1835) in representative environments across the base of the southeastern Mediterranean margin (cold water coral, active seepage pockmark and deep sea channel areas). In some core intervals, yellowish, recrystallized internal molds of this species are present. They have been previously observed in the Eastern Mediterranean, but the nature and origin of their colour was never explained. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Electron Backscatter Diffraction (EBSD) revealed that the recrystallized molds of the H. inflatus shells are formed by aragonite needles and high-Mg calcite crystals. The formation and preservation of these internal molds is induced by advective methane emissions, typically precipitating aragonite and High-Mg calcite phases close to the sediment–water interface. These molds were never used in previous applications of the LDX or in any existing ranking of pteropod preservation. Therefore, we have categorized these peculiar features combining previous pteropod ranking descriptions with the new observations to develop a modified biotic index (Heliconoides Modified Dissolution Index-HMDI). High values of the HMDI at the base of the pockmark core correspond to the interval where also active seepage-related features – e.g., bubble emissions, low-oxygen benthic foraminifera, chemosymbiotic molluscs, small fragments of authigenic carbonate crusts and slightly depl

Sedimentary records depicting significant variability in climate and carbon cycling across the early Paleogene have emerged over the last two decades. Continuous, long-term, high-resolution records mostly derive from deep-sea drill cores, and only few derive from continental margin locations. Here we examine lower Paleogene marls and chalks collected from a core (RH-323) in the Northern Negev Desert (Southern Israel). The studied sediments accumulated on a continental slope of the southern Tethys at ~500–700 m paleodepth and did not undergo deep burial. We analyzed bulk carbonate stable carbon and oxygen isotopes and bulk magnetic susceptibility. The resulting records can be aligned with those from elsewhere and include the Paleocene Carbon Isotope Maximum (PCIM), Paleocene Eocene Thermal Maximum (PETM) and Early Eocene Climatic Optimum (EECO). An obvious realization is a concurrence between local lithological variations and major climate and carbon cycle changes. This has been highlighted for sedimentary sequences elsewhere, but the relations differ in the Negev, such that carbonate rich intervals mark the PCIM and PETM, and a transition from marl to chalk initiates the EECO. Overall, the relatively pristine and immature sediment records in southern Israel likely provide potential for high-resolution paleoclimate and carbon cycle reconstructions during a crucial time interval and in a crucial part of the world.

Several oil shows have been reported from offshore and onshore wells of the Levant Basin, which promoted research and exploration as indicators for potential economic discoveries in the yet unpenetrated Mesozoic interval of the basin. In most cases, no definitive source to oil correlation has been established, advocating the need for the fingerprinting of regional source rocks to compare their organic geochemical signatures to those of oils. A summary of known properties of oils sampled from different wells in the region raised several questions regarding source–oil and oil–oil correlation, maturity, and source of the organic matter. In this part of the project we examined the Cretaceous section in the region by conducting a sedimentological and organic geochemical investigation of organic-rich intervals from ODP well material and onshore wells in the Levant region. We show that organic-rich Upper Cretaceous deposits, Turonian OAE2, and lowermost Cretaceous Barremian organic-rich deposits, should be considered as viable candidates for sourcing hydrocarbon formation in the deep basin, where they might have matured.

Chemosymbiotic micro- and macro-fauna related to cold-seep sites were recovered in the Palmahim Disturbance (PD), offshore Israel, during EU EUROFLEETS2 SEMSEEP Cruise, by box-coring and Remotely Operated Vehicle (ROV) dives. No live macrofauna was identified in the collected sediments, with the exception of the seep-related crustacean Calliax lobata (de Gaillande and Lagardère, 1966). Numerous Calliax claws testify the past colonization of these soft bottoms by several generations of this ghost shrimp. After sediment sieving on 1 mm, we identified gastropods belonging to the families Trochidae, Eucyclidae, unassigned Seguenzioidea (genus Anekes), Rissoidae, Elachisinidae, Raphitomidae, Mangeliidae, Architectonicidae, Orbitestellidae, and Acteonidae. The identified bivalves belong to the families Nuculidae, Yoldiidae, Mytilidae, Lucinidae, Thyasiridae, Semelidae, Kelliellidae, Vesicomyidae, Xylophagidae, and Cuspidariidae. A seep-related group of chemosymbiotic molluscs was detected, including: Taranis moerchii (Malm, 1861), Lurifax vitreus Warén and Bouchet, 2001, Idas ghisottii Warén and Carrozza, 1990, Lucinoma kazani Salas and Woodside, 2002, Thyasira biplicata (Philippi, 1836), Isorropodon perplexum Sturany, 1896, and the newly described Vesicomyid species Waisiuconcha corsellii n. sp., that represents also the first record of the genus Waisiuconcha in recent Mediterranean sediments. The ROV dives recorded local patches of several m2 of seafloor covered by dead shells of L. kazani, with a density of up to about 200 loose shells per square meter. The potential occurrence of seep-related foraminifera, among low-oxygen tolerant species, was explored by comparison with previously sampled adjacent localities, and lead to the identification of Chilostomella oolina, Globobulimina affinis and G. pseudospinescens as potential foraminiferal seep indicators in the southeastern Mediterranean Sea. The absence of live, seep-related fauna in surface sediments in the PD, wh

Large national programs in the United States and several Asian countries have defined and characterised their marine methane hydrate occurrences in some detail, but European hydrate occurrence has received less attention. The European Union-funded project “Marine gas hydrate – an indigenous resource of natural gas for Europe” (MIGRATE) aimed to determine the European potential inventory of exploitable gas hydrate, to assess current technologies for their production, and to evaluate the associated risks. We present a synthesis of results from a MIGRATE working group that focused on the definition and assessment of hydrate in Europe. Our review includes the western and eastern margins of Greenland, the Barents Sea and onshore and offshore Svalbard, the Atlantic margin of Europe, extending south to the northwestern margin of Morocco, the Mediterranean Sea, the Sea of Marmara, and the western and southern margins of the Black Sea. We have not attempted to cover the high Arctic, the Russian, Ukrainian and Georgian sectors of the Black Sea, or overseas territories of European nations. Following a formalised process, we defined a range of indicators of hydrate presence based on geophysical, geochemical and geological data. Our study was framed by the constraint of the hydrate stability field in European seas. Direct hydrate indicators included sampling of hydrate; the presence of bottom simulating reflectors in seismic reflection profiles; gas seepage into the ocean; and chlorinity anomalies in sediment cores. Indirect indicators included geophysical survey evidence for seismic velocity and/or resistivity anomalies, seismic reflectivity anomalies or subsurface gas escape structures; various seabed features associated with gas escape, and the presence of an underlying conventional petroleum system. We used these indicators to develop a database of hydrate occurrence across Europe. We identified a series of regions where there is substantial evidence for hydrate occurrence (

Seafloor video surveys were carried out with the ROV Max Rover in the Palmahim Disturbance (PD) area, offshore Israel, in September 2016 during the EUROFLEETS2 SEMSEEP cruise on board the R/V AEGAEO. Preliminary observations of distribution and frequencies of bivalve accumulations show that they are mostly composed by Lucinoma kazani shells. Valves are distributed mainly along the base of authigenic carbonate crusts, in association with bacterial mats and inside inactive chimney-like structures, sometimes associated with crabs and living tubeworms. However, no living molluscs were observed. The relation between distribution of bivalve beds and seepage activity is not straightforward in the PD area. However, the presence of these accumulations and the size of L. kazani, suggest that seepages may have lasted for at least one decade, before its reduction/cessation that induced L. kazani mortality. The presence of few articulated valves of this species indicates that they were alive up to one year before the ROV observations and their different preservation state may imply different seepage phases. This research shows that chemosymbiotic benthic communities may be used as a proxy for better understanding the past dynamics of fluid emissions at the seafloor. However, further quantitative studies are needed to confirm these observations.

Ashkenazi, L., Katz, O., Abramovich, S., Almogi-Labin, A., Makovsky, Y., Gadol, O., ... & Hyams-Kaphzan, O. (2022). Benthic foraminifera as indicators of recent mixed turbidite-contourite sediment transport system in the Eastern Mediterranean upper continental slope, offshore Israel. Marine Geology, 106756. https://doi.org/10.1016/j.margeo.2022.106756

Ashkenazi, L., Katz, O., Abramovich, S., Almogi-Labin, A., Makovsky, Y., Gadol, O., ... & Hyams-Kaphzan, O. (2022). Benthic foraminifera as indicators of recent mixed turbidite-contourite sediment transport system in the Eastern Mediterranean upper continental slope, offshore Israel. Marine Geology, 106756. https://doi.org/10.1016/j.margeo.2022.106756

Chemosymbiotic micro- and macro-fauna related to cold-seep sites were recovered in the Palmahim Disturbance (PD), offshore Israel, during EU EUROFLEETS2 SEMSEEP Cruise, by box-coring and Remotely Operated Vehicle (ROV) dives. No live macrofauna was identified in the collected sediments, with the exception of the seep-related crustacean Calliax lobata (de Gaillande and Lagardère, 1966). Numerous Calliax claws testify the past colonization of these soft bottoms by several generations of this ghost shrimp. After sediment sieving on 1 mm, we identified gastropods belonging to the families Trochidae, Eucyclidae, unassigned Seguenzioidea (genus Anekes), Rissoidae, Elachisinidae, Raphitomidae, Mangeliidae, Architectonicidae, Orbitestellidae, and Acteonidae. The identified bivalves belong to the families Nuculidae, Yoldiidae, Mytilidae, Lucinidae, Thyasiridae, Semelidae, Kelliellidae, Vesicomyidae, Xylophagidae, and Cuspidariidae. A seep-related group of chemosymbiotic molluscs was detected, including: Taranis moerchii (Malm, 1861), Lurifax vitreus Warén and Bouchet, 2001, Idas ghisottii Warén and Carrozza, 1990, Lucinoma kazani Salas and Woodside, 2002, Thyasira biplicata (Philippi, 1836), Isorropodon perplexum Sturany, 1896, and the newly described Vesicomyid species Waisiuconcha corsellii n. sp., that represents also the first record of the genus Waisiuconcha in recent Mediterranean sediments.The ROV dives recorded local patches of several m2 of seafloor covered by dead shells of L. kazani, with a density of up to about 200 loose shells per square meter. The potential occurrence of seep-related foraminifera, among low-oxygen tolerant species, was explored by comparison with previously sampled adjacent localities, and lead to the identification of Chilostomella oolina, Globobulimina affinis and G. pseudospinescens as potential foraminiferal seep indicators in the southeastern Mediterranean Sea. The absence of live, seep-related fauna in surface sediments in the PD, where

Seafloor video surveys were carried out with the ROV Max Rover in the Palmahim Disturbance (PD) area, offshore Israel, in September 2016 during the EUROFLEETS2 SEMSEEP cruise on board the R/V AEGAEO. Preliminary observations of distribution and frequencies of bivalve accumulations show that they are mostly composed by Lucinoma kazani shells. Valves are distributed mainly along the base of authigenic carbonate crusts, in association with bacterial mats and inside inactive chimney-like structures, sometimes associated with crabs and living tubeworms. However, no living molluscs were observed.The relation between distribution of bivalve beds and seepage activity is not straightforward in the PD area. However, the presence of these accumulations and the size of L. kazani, suggest that seepages may have lasted for at least one decade, before its reduction/cessation that induced L. kazani mortality. The presence of few articulated valves of this species indicates that they were alive up to one year before the ROV observations and their different preservation state may imply different seepage phases. This research shows that chemosymbiotic benthic communities may be used as a proxy for better understanding the past dynamics of fluid emissions at the seafloor. However, further quantitative studies are needed to confirm these observations.