Mechanism of formation and stages of development of the East Sea

Abstract

There have been many models of formation and development of the East Sea. These models have a common feature that the mechanism of the East Sea formation is based on only one unique force source. Up to now, no consensus has been reached on the mechanism of the East Sea formation between scientists. Based on the analyses of tectonic events, models of the East Sea formation, seismic cross-sections, fracture deformation and analyses of petrotectonic assemblages, the authors have proposed a model combining 3 force sources: a source caused by collision of plate, generating extrusion movement; a source caused by slab pull; and a source caused by mantle. Three force sources have played different roles in the history of the East Sea and been assessed in three stages of development: stage of prespreading, stage of spreading, and stage of post-spreading. In the stage of prespreading, the area of the East Sea was affected by three force sources: plate collision, subduction and mantle. In the stage of spreading, the left lateral strike of Red River fault played the beginning of spreading, but the mantle force was main one controlling development. In the post-spreading stage thethermal subsidence controlled development and created the form of recent East Sea.