MASCLE , Jean

Transform, or sheared, continental margins are generated at first as consequences of large-scale intra-continental strike-slip displacements, then as the results of successive shear motions between progressively thinning continental crusts and, finally, active motions along oceanic lithosphere. They, later on, give birth to oceanic fracture...

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International audience

The Phanerozoic geological evolution of the Equatorial Atlantic domain has been controlled since the end of Early Cretaceous by the Romanche and Saint Paul transform faults. These faults did not follow the PanAfrican shear zones, but were surimposed on Palaeozoic basins. From Neocomian to Barremian, the Central Atlantic rift propagated...

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One of the objectives of the European project SEAHELLARC (SEismic and tsunami risk Assessment and mitigation scenarios in the western HELLenic ARC) was to identify the key elements controlling the geological structure of the Peloponnese continental margin in order to better understand the distribution of earthquakes in the area. Vintage...

Large deep-sea fans are useful settings to study gas hydrate systems, the rapid burial of organic-rich sediment driving linked processes of gas generation, fluid expulsion and syn-sedimentary tectonism. The Nile deep-sea fan (100,000 km2) is a collapsing Late Cenozoic depocentre that is both a hydrocarbon province and an area of widespread...

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Numerous deep-water play types have been identified along the transform margin of NW Egypt. A large segment of the offshore Matruh Basin has play types related to a prominent shale décollement within the Matruh Canyon. The footwalls of the growth faults associated with the shale detachment provide fault-controlled three-way closures very...

The Nile deep-sea fan (NDSF), turbiditic system reaching a size of about 90,000 km2, has been investigated since 1998 by several geophysical methods (multibeam bathymetry, backscatter imagery, seismic data, 3–5 kHz echo-sounding). The analysis of this important data set evidenced that the NDSF is the locus of numerous multi-scale slope...

The occurrence of mud volcanoes (MVs) in the deep Ionian Sea was first recognised in the early 1980s from the recovery of cores of mud breccia, initially hypothesised to record tectonic or diapiric processes, but eventually shown to record a long (> 1 Ma) history of seafloor extrusion from the accretionary prisms along the Europe-Africa...

Based on a recent marine geophysical data set, including swath bathymetry, acoustic imagery and six-channel seismics, recorded over a large area of the Mediterranean Ridge (MR) in early 1998 during the Prismed 2 survey, this paper presents a study of the various relationships observed between tectonic features cutting across the Central...

Existing knowledge on the distribution of mud volcanoes (MVs) and other significant fluid/free gas-venting features (mud cones, mud pies, mud-brine pools, mud carbonate cones, gas chimneys and, in some cases, pockmark fields) discovered on the seafloor of the Mediterranean Sea and in the nearby Gulf of Cadiz has been compiled using regional...

Gas hydrates have been proven by coring at one site in the (eastern) Mediterranean Sea, but their wider extent remains uncertain. Here we present results from investigations of the potential Mediterranean gas hydrate system, suggesting that clathrates occur more widely and have been strongly impacted by glacial-interglacial climate forcing....

The Nile deep-sea fan is the largest Plio-Quaternary depocentre in the Mediterranean Sea, extending over an area of >150,000 km2 within which rapid deposition drives syn-sedimentary collapse tectonics, as well as widespread seafloor venting of mixed thermogenic and biogenic gases. It is thus an ideal setting for the near-seabed accumulation of...

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The central Nile Deep-Sea Fan contains a broad area of seabed destabilisation in association with fluid seepage: slope-parallel sediment undulations are associated with multibeam high-backscatter patches (HBPs) related to authigenic carbonates. During the 2011 APINIL campaign, a deep-towed sidescan and profiling system (SAR) was used to acquire...

This paper reports the first "in situ" seafloor observations of fluid escape structures in a fault-controlled caldera-type depression of about 8 km diameter, named the Menes caldera, in the Eastern Mediterranean sea off Egypt (western province of the Nile Deep Sea Fan). A detailed analysis of seven Nautile dives, performed during the Nautinil...

Marine sediments at ocean margins vent substantial amounts of methane. Microbial oxidation of the methane released can trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems. The factors controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid...

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Marine sediments at ocean margins vent substantial amounts of methane. Microbial oxidation of the methane released can trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems. The factors controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid...

International audience