When two tectonic plates converge in a direction that is not perpendicular to the boundary between them, there are shear forces generated between the plates acting parallel to the boundary. If this convergence occurs along a gently-dipping thrust fault then the upper plate may be, and very often is, deforming rapidly. In many cases the part of the upper plate that rests on the subducting plate gets torn and moves along the margin, separated from the rest of the upper plate by a margin-parallel strike-slip fault. In this study the P.Is. will examine the factors that control this process and from this will gain an improved understanding of the forces acting on the margin as well as the material properties of the Earth. They will compile information on the process of strain partitioning globally as a guide to numerical computer experiments that simulate oblique subduction. The main goals are to understand what measurements of deformation in this setting can tell us about the forces and rheology in convergent margins and also to understand in general terms the factors that produce strike-slip faults.
