PROUST , Jean-Noël

The subduction of the Nazca Plate below the South American Plate shows the subduction ofaseismic ridges of different origins and morphologies. One of them is the Carnegie Ridge (400kmwide, 2km high) produced by the relationship between the Galapagos Hotspot and the GalapagosSpreading Center. The ages and the effects of the Carnegie Ridge...

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La croissance de la chaine côtière en Equateur est largement la conséquence de la subduction dela ride de Carnegie (400 km de long, 2 km d'altitude) débutée voilà au moins c.1,5 Ma. Cette chainea dévié les flux sédimentaires issus des Andes, sous alimentant la fosse et le plan de subduction.L'origine, le calendrier, l'amplitude et la...

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The uplift of the coastal cordillera of central Ecuador is a likely consequence of the subduction of the Carnegie Ridge, a 400-km-long and 2-km-high topographic asperity. This study aims at analyzing the impact of the subduction of the Carnegie Ridge on the continental shelf sedimentation during the Quaternary. We interpret high-resolution...

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The Ecuadorian convergent margin is characterized by the subduction of the Nazca oceanic plate beneath South America at an average of 6-7 cm/year (Nocquet et al., 2014). The geodynamic evolution of the margin is influenced by the subduction of the Carnegie Ridge and by the NE migration of the North-Andean Block.Along the continental shelf, the...

Along the Ecuadorian convergent margin, the onshore Manabí sedimentary forearcbasin is bounded to the east by the foothills of the Andes, while to the north and west, itis limited by the Canandé and Jama fault systems. The fault systems limit basementblocks resulting from the fragmentation of an oceanic plateau topped by island arcs,which were...

Forearc basins have developed along accretionary and nonaccretionary convergent margins. Here, we investigate the evolution of an offshore nonaccretionary-type forearc basin that has developed along the Ecuadorian convergent margin. We used 2D-Multichannel Seismic Reflection profiles to recognize five seismic units overlying the acoustic...

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Recent deep marine sedimentation in subduction trenches ischaracterized by the inter-stratification of hemipelagic and turbiditesediments locally interbedded with debris flows, which canresult from continental slope shaking by large earthquakes. Theobjective of this study is to describe the morphologic complexityon the Ecuadorian border of the...

The active margin of Ecuador is characterized by strong tectonic erosion that contributes to the formation of adeep trench filled by a complex suite of sedimentary facies. Gravity flow sedimentation is ubiquitous along themargin and facies range from laterally continuous m-thick mass transport deposits to isolated cm-thick...

La subduction de monts sous-marins est connue pour affectersignificativement les marges actives, en augmentant l'érosion tectonique.Par ailleurs, la participation des monts sous-marins àla nucléation/couplage au niveau des grands séismes de subductionest en plein débat. Des modèles analogiques ont montré lesprincipales caractéristiques de ces...

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We investigate the evolution of the onshore Manabí forearc basin in Ecuador, which has developed on accreted oceanic terranes. We use 2D seismic profiles to identify 10 seismic units, separated by 9 unconformities. These units were dated by correlation with Ricaurte-1 well and regional stratigraphy. Unit S1 represents the first depocenter...

Forearc basins serve as a sedimentary archive of sea-level variations and subduction-related tectonic processes. Along the Ecuadorian convergent margin (0°40'N-2°20'S) we interpreted a dense network (one profile every 4 km) of MCS reflection profiles acquired by the Ecuadorian State during the 2009 SCAN cruise with a 8-km-long, 640-channel...

La ride de Carnegie est un plateau océanique résultant de l'interaction Miocène à actuel entre lepoint chaud des Galápagos et la dorsale Nazca-Cocos. Sur les flancs de cette ride, la couverturesédimentaire carbonatée montre des zones parsemées de champs de dépressions sub-circulaires fermées,de 2 à 3 km de diamètre, parfois de 300 à 400 m de...

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