The effect of seamount chain subduction and accretion

Abstract

Seamount chains (oceanic plateaus, submarine ridges) are unique morphologic features on the seafloor, which resulted from the motion of the lithosphere over a convective plume. Seamount chains are being carried along by plate motions, which are eventually subducted beneath continental/oceanic plates or accreted in the accretionary complex, thus causing a series of effects in the convergent margin. In this paper, we briefly review the distribution and features of the typical modern seamount chains, including Hawaiian‐Emperor and Louisville seamount chains, Cocos, Ninetyeast and Caroline ridges, and Ogasawara Plateau, and mainly focus on the effects of seamount chains subduction and accretion. The geological effects mainly include the following: (1) deformation and tectonic erosion of the overriding plate; (2) flat‐slab subduction in the convergent margin; (3) growth of continental crust through time; (4) subduction initiation of plate tectonics; (5) generation of large earthquakes; (6) magmatism of the volcanic arc; and (7) formation of porphyry copper and gold deposits. The subduction of seamount chains resulted in similar effects in the Central Asian Orogenic Belt (CAOB) which is one of the largest and longest‐lived accretionary orogens on Earth. However, there are still many aspects that need further improvements, such as identification of the seamounts in the geological record, and geodynamic effects of subducted seamount chains. A detailed study on these sides of the seamount chains will enable us to further understand the tectonic evolution and metallogenesis of the CAOB, especially in accretionary orogenesis, continental crust growth, and subduction initiation dynamics.