The boundary between two continental plates. These are hybrid margins since the two slabs of continental crust that eventually collide were initially separated by oceanic crust, with passive or destructive margins; when the oceanic crust is consumed, the two continental crusts collide. The lower continental plate forms a double layer of crust together with the upper plate, as in the Himalayas; see D. S. N. Raju et al. (2005).