Seabed pockmarks and their bearing on salt movement in Lower Congo Basin of western African

Based on high resolution 3 D seismic data, the characteristics of seabed pockmarks and their relationship with salt movement are systematically studied in this paper.There are two types of pockmarks, i.e.the deep V-shaped and the shallow U-shaped pockmarks, distributed in the east and west of the study area respectively.The distribution pattern of pockmarks depends upon underlying salt movement.The V-type pockmark is resulted indirectly from the compressive stress on seabed caused by salt diapers in the east area, while the U-type pockmark resulted indirectly from the extensional stress on seabed caused by salt canopy in the west area.Both the pockmarks are formed by seabed rupturing and erupting of high pressure strata water directly triggered by underlying salt structure movements.