Orogen-scale transpression accounts for GPS velocities and kinematic partitioning in the Southern Andes

Abstract The Southern Andes are regarded as a typical subduction orogen formed by oblique plate convergence. However, there is considerable uncertainty to how deformation kinematically partitioned in the upper plate. Here we use analogue experiments conducted MultiBox (Multifunctional Box) apparatus investigate dextral transpression between 34 °S and 42 °S. We find that our models caused mainly two prominent fault sets; zone-parallel oblique-slip thrust faults sinistral reverse faults. latter of these sets may be equivalent northwest-striking which were believed pre-Andean origin. also model variable crustal strength stronger crust north 37 weaker south best reproduces observed GPS velocity field. propose accommodated distributed rather than localized displacements on few margin-parallel