... in the abyssal with the depth over 200 meters. The Eastern Sea abyssal is the place where the oceanic crust exposed in the form of triangular shape with the right line oriented NE-SW and the ... as the South Central part of Vietnam, subsidence had occurred periodically (cycliclty) for whole basins both on the land and in the ocean area. Therefore, the coarse layer in the lower part of ... terraces. Conversely, in the central part of the Cenozoic basins (such as the Red River rift, the Mekong river rift, the South Con Son rift, the Phu Khanh rift, ), and in the subsided monocline...