Figure 4

Strain rate (shown in vertical cross-sections and plan view) and rock uplift rates (top view) after 6 Myr modelling time for (a) model 2 (total erosion; no upper plate advance); (b) model 3 (fluvial erosion; no upper plate advance); and (c) model 4 (fluvial erosion; half upper plate advance). Figure conventions as in Fig. 3. Note that in the models without the upper plate advance component (panels “a” and “b”), the relatively shallow (i.e., originated at 10–20 km depth) particle streamlines show a gradual increase in exhumation of upper and lower crustal material from the left (subduction) side of the model towards its center. In the experiment characterized by fluvial erosion and half upper plate advance (panel “c”), the zones of strong rock uplift at the surface coincide with the three main deformation structures of the model: (1) the orogenic wedge above the cylindrical slab; (2) the indenter-centered decollement; and (3) the transform fault bounding the lateral margin of the subducting plate (see Fig. 3b).