MARCAILLOU , Boris

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A multidisciplinary team is jointly investigating mammal evolution and subduction dynamics to unravel how flightless land mammals migrated to the Greater Antilles and other Caribbean islands.

In 2005, an onshore, offshore 3‐D refraction and wide‐angle reflection seismic experiment was conducted along the convergent margin at the border between Colombia and Ecuador, over the rupture zone of the 1958, Mw 7.6 subduction earthquake. A well‐defined Vp velocity model of the plate boundary and upper and lower plates was constructed, down...

In subduction zones, questioning the causes for variations in interplate coupling and interplate slip behavior implies deciphering how much deep fluid content and flux influence thermo-mechanical features along the plate interface. A key-question in fluid-rich subduction zones is: how ventilated and insulated hydrothermal systems in basaltic...

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The influence of the highly oblique plate convergence at the northern Lesser Antilles onto the margin strain partitioning and deformation pattern, although frequently invoked, has never been clearly imaged. The Anegada Passage is a set of basins and deep valleys, regularly related to the southern boundary of the Puerto Rico-Virgin Islands...

Three main types of factors commonly control the nature of the clasts, the arrangement of the distinctive lithologies, and the general architecture of turbidite systems: sedimentation rate and carbonate production; climates and glacio-eustatism; and morphology and tectonics. The coexistence of adjacent systems of distinctive nature is, however,...

International audience

The Lesser Antilles subduction zone has produced no recent strong thrust earthquakes, making it difficult to quantify the seismic hazard from such events. The Lesser Antilles arc has a low subduction rate and an accretionary wedge that is very wide at its southern end. To investigate the effect of the wedge on seismogenesis, numerical models of...

Along the convex Northern Lesser Antilles margin, plate convergence obliquity increases northward resulting in subduction normal to the trench to the west of Guadeloupe and highly oblique (>75°) to the North of Virgin Island. In this context, tectonic structures related to strain partitioning has long been debated, but are still poorly imaged....

International audience

Forearc sedimentary basins record changes in tectonic regime and are thus key area to investigate the tectonic history of a subduction zone through time.Since Cretaceous, The Lesser Antilles subduction zone has undergone a multiphase tectonic history resulting in its present-day complex architecture. One peculiar aspect for this subduction is...

International audience

International audience

The purpose of the GAARAnti project is to unravel couplings between deep Earth dynamics and evolutionary processes through an innovative and original multi-disciplinary study combining Earth and Life sciences. This innovative approach will reconcile biological and geological clocks and timeframes through the combined use of radiochronological...

Offshore 2D-Multichannel seismic (MCS)-reflection profiles were acquired in northern Ecuador during the HIPER survey (March/April 2020, R/V L'Atalante) together with one 2D-OBS-seismicrefraction profile (presented in a joint abstract by A. Skrubej). This project (presented in a joint abstract by A. Galve) aims at deciphering the role of lower...

Numerous submarine plateaus form highstanding bathymetric highs at continent to ocean transitions. Due to their proximity to continents, they have been frequently labelled "marginal plateaus", although this term has not been clearly defined or associated with a specific geology or geodynamic process. Until now, these elevations have been...

Megadeposits such as Homogenite-Turbidite complexes (HmTu) are often retrieved in the deepest part of confined seas (Mediterranean, Marmara), in fjords or in lakes. Megadeposits are generally triggered by earthquakes and tsunamis but other factors such as climatic or volcanic events remain possible. Only few studies mention such deposits in...

International audience

International audience

Oceanic crust formed at slow-spreading ridges is currently subducted in only a few places on Earth and the tectonic and seismogenic imprint of the slow-spreading process is poorly understood. Here we present seismic and bathymetric data from the Northeastern Lesser Antilles Subduction Zone where thick sediments enable seismic imaging to greater...

International audience

International audience

Phylogenetic studies of present-day terrestrial organisms suggest that faunal dispersals between South America and the Greater Antilles may have occurred during the Cenozoic through the Lesser Antilles. However, because of the lack of geological data to unravel the areas that may have emerged along the Lesser Antilles trench, the migration...