巽他海沟和弧前地区的沉积作用主要是陆源碎屑的搬运,这些陆源碎屑物来自印度洋东北部周缘的造山和火山区。喜马拉雅石英质碎屑物被搬运进入孟加拉湾并沿巽他海沟轴部向南分布远至巽他海峡。在外弧脊发育以前,大多数岛弧来源的沉积物越过前弧盆地沉积在海沟中。几乎所有在新第三纪时期来自爪哇和苏门答腊弧的沉积物都被截阻在弧前盆地内。没有达到海沟区。 Sediments in the Tau Trench and Pre-Arctic are mainly the transport of terrestrial debris from orogen and volcanic areas in the northeastern Indian Ocean. Himalayan quartz debris was transported into the Bay of Bengal and distributed as far as the Straits of Strait along the axis of the Sunda Trench. Prior to the development of the outer ridges, most of the island arc-derived sediments deposited in the trench across the forearc basin. Almost all sediments from the Java and Sumatran arcs in the Neogene were trapped in pre-arcuate basins. Did not reach the trench area.