The physical characteristics of successive layers of sediments at the time of deposition vary widely; in particular, the equilibrium angle of the foreset slope of sedimentation. When a layer of soft sediments, like shale, with a low slope of deposition (approximately 1°) succeeds a layer of harder sediments with steeper slope, like limestone and marl, a period of slope readjustment takes place. During this period, a dumping of sediments at the base of the limestone "cliff" accompanied by synchronous regressive erosion of the top of the "cliff" by submarine canyon occurs. The Gabon sedimentary basin and the Aquitaine Basin provide examples of the slope readjustment theory. The importance and possible generalization of this theory are discussed in this article. his phenomenon is concomitant with more general effects such as tectonic phases, isostatic readjustment, eustatic changes, and crust movements.