Modelos tectono-sedimentarios de cuencas extensivas: serhigraben, graben de compensación y sinclinal sobre rampa (margen pasivo del Golfo de León, SE de Francia)

Abstract

Three tectono-sedimentary models are proposed for extensiona/basins in the Guif of Lion passive margin: (1) haif-graben associated to a listric fault, (2) compensation graben associated to a two-segments planar fault and (3) hangingwall ramp syndine associated to a ramp-flat listric fault. In the Vistrenque graben, along-strike changes in the geometry of the Nimes fault induced along-strike changes of the geometry of the basin: in the south, a half-graben resulted from a listric fault profile at depth; in the north, a compensation graben results from a two-segments planar fault profile. The Les Matelles basin is a hangingwall syncline which results from a ramp-flat listric fault geometry. Erosion of the hangingwall during extension controlled the architecture of the syn-rift sedimentation, resulting in a rapid migration of the depocentres towards the fault.