Mode of continental breakup of marginal seas

Abstract We investigated the continent-ocean transition (COT) structure of three main marginal seas in western Pacific Ocean (South China Sea, Coral and Woodlark Basin) to determine tectono-magmatic processes acting during continental breakup. The COT formed from activity a low-angle normal fault system localizing deformation final rifting. Extension was contemporaneous with magmatic activity, including volcanic edifices, dikes, sills distalmost parts these basins. shows sharp juxtaposition space time crust against igneous oceanic crust, its overall differs that magma-poor or magma-rich passive-margin archetypes. propose this mode breakup is characteristic due high extension rates imposed by kinematic forces nearby subduction zones. Revealed context seas, resulting structures highlight underestimated diversity mechanisms.