South-American plate advance and forced Andean trench retreat as drivers for transient flat subduction episodes

Abstract

How flat slabs at subduction zones are created remains unclear. Here, the authors show that the Nazca slab has retreated at ∼2 cm per year since 50 Ma but no rollback has occurred in the last ∼12 Myr in the flat slab, implying that an overpressured sub-slab mantle can impede rollback and maintain a flat slab.