Seismic Structure of the Caroline Plateau‐Yap Trench Collision Zone

Abstract

AbstractCollision of oceanic plateaus with trenches has played a key role in the continental growth and plate tectonic reorganizations throughout the Earth's history. However, the understanding of collision between an initially rifted plateau with a trench is still deficient. Here we conduct the first seismic tomography and receiver function analyses in the Yap subduction zone, western Pacific Ocean, where the initially rifted Caroline Plateau is colliding with the Yap Trench. Our results reveal horizontal and overturned slabs south and north of the Sorol Trough, respectively, which may be caused by slab breakoff followed by underplating and eastward mantle flow with ultra‐slow convergence. The distinct slab morphologies could be responsible for the short‐lived arc volcanism (11‐7 Ma), horst‐graben structures, different Bouguer gravity anomalies and stress regimes in the Yap subduction zone. The overturned slab may cause the incoming plateau to be stretched to facilitate the initial plateau subduction.