In this paper, we describe a geometrical algorithm to solve the problem of the kinematics at basin scale. Two elementary models of geological deformation are considered: flexural slip and vertical shear. The combination of these models enable us to properly describe mechanical stratigraphy of a sedimentary basin sequence.<br><br>The methodology presented is 3D, reversible, simple to implement and fast. Validations are presented on two different examples: one synthetic to validate the algorithm, and a structurally complex model.<br>