Dynamic models of continental rift valley systems

Abstract

In experimental scale models simulating the major continental rift valley systems rifting is caused by diapiric uprise of viscous material induced by a centrifugal body force; this force plays the same role as gravity in nature. The scale models show that bending alone as a mechanism of rifting is unrealistic. Rather, the rift structures form as a result of the combined effect of gentle bending and lateral stretching of the crust. The models also show that graben structures could form at any stage of development of an ascending and laterally spreading diapiric body depending upon the density and viscosity contrast of the body and its surroundings and the strength of the model crust. The close resemblance in structure of the models with natural rift systems suggests a close similarity of dynamics and driving forces.