Franciscan mélanges: coherent blocks in a low-density, ductile matrix

The Franciscan Complex comprises the largely sedimentary basement of the California Coast Ranges. This classic trench deposit has undergone a series of superimposed tectonic events since the end of Jurassic time, involving accretion, high-pressure (HP) recrystallization, buoyancy and wedge-driven exhumation, and transcurrent slip. Processes reflect plate convergence, transpressive-orthogonal subduction, and transpressive–transtensive offset....