Rapid Continental Subsidence Following the Initiation and Evolution of Subduction

Abstract

Dynamic topography resulting from initiation of slab subduction at an ocean-continent margin causes the continental lithosphere to subside rapidly. As subduction continues and the slab shallows, a basin depocenter and forebulge migrate in toward the continental interior. Finally, closure of the ocean basin leads to regional uplift. These active margin processes have commonly been ascribed to supracrustal loading, but numerical modeling shows that dynamic subsidence rates can exceed 100 meters per million years and are similar to rates of sediment accumulation along convergent North American plate margins over the Phanerozoic.