The researchers studied river terraces in the Pearl River Delta and nearby areas. They found that there are 3-4 stages of terraces, with the first stage being semi-buried terraces with characteristics of natural levees and aggradations. The terraces and flood plains make up the alluvial plain. The region has experienced intermittent uplift during the middle Pleistocene Epoch, but since the late Pleistocene Epoch, there has been intermittent subsidence or stabilization. The Pearl River Delta is not a block type delta, and small streams cut across faults with no evident morphogenesis since the late Pleistocene Epoch.