The Significance of Ramps and Flats of Mass Transport Deposits (MTD) as Kinematic Indicators

Ramps and flats of mass transport deposits are commonly studied on seismic profiles as kinematic indicators. In this study, ramps and flats on the margin of salt diapirs are mapped in a high quality 3D seismic volume from SE Brazil (Espírito Santo Basin). Our aim is to test how differently oriented ramps and flats at the basal shear surface of specific MTD interval can be used to infer the direction of mass flow. Statistical analysis of thickness variation of the mass transport deposit within depocentre created by ramps and flats was estimated along slope in order to elucidate the mode of emplacement of the associated MTD. Sliding at the plane of failure is enhanced by seafloor faulting and nearby halokinesis. Ramps significantly contribute to local changes in gradient at the basal shear surfaces, as they are linked to promontories (Type I) and paleo-fault scarps (Type II).