Caracterización morfológica y estructural de nuevos volcanes de fango en el margen marroquí del Golfo de Cádiz

Abstract

The mud volcanism in the Iberian and Moroccan margins of the Gulf of Cadiz is well known over more than a decade. Nevertheless, new structures and morphologies related to fluid venting are still discovered in the recent oceanographic cruise SUBVENT2 in 2014 along the Moroccan margin. Four new mud volcanoes have been identified along two sector of Moroccan margin. Two of them in the Eastern Moroccan Margin - EMF (Subvent and Rosco mud volcanoes), located in the upper slope between 350 and 500 m depth. The other two in the Western Moroccan Margin - WMF (Demetrio de Armas and Port Royal), located in the middle slope at 1800 m depth. The main aim of this paper is the morphological characterization of these new mud volcanoes using swath bathymetric data to analyze the relation between tectonic and sedimentary processes with multiparametric sounder and high resolution multichannel seismic profiles. The interpretation of these seismic profiles show that the source of expelled material of mud volcanoes in the EMF is buried under a sedimentary cover of contouritic deposits of 200 m thickness. A high sedimentation rate can cause an increase of pressure that could act as triggered of mud volcano edificies. In the WMF, the new mud volcanoes are developed related to thrust of the Allocthonous Unit of the Gulf of Cadiz. The origin of these structures is mainly related to de NW-SE tectonic compression .