Evidence for non-lithostatic pressure in subducted continental crust

Continental crust buried during collisional orogeny typically records pressures of 3 GPa or lower; however, pressures much higher than this are recorded locally, which would suggest burial to mantle depths. Deep continental subduction is not observed in active orogens and should be hindered by the positive buoyancy of sialic crust relative to the mantle. Non-lithostatic pressure caused by mechanical contrasts between rock types provides an...