珠江三角洲的新构造运动及其与三角洲演化的关系

综合已有资料。重新对珠江三角洲的新构造运动进行了系统的分析．分析结果表明该地区的新构造运动以断裂活动和断块差异升降运动为主要特征．这些特征在珠江三角洲的演化过程中起着非常重要的作用。大多数在第四纪形成或重新活化的基底断裂把三角洲切割成一系列的断块，并且在垂直运动上以沉降为主导，为珠江三角洲的第四系沉积创造了空间。另外，第四系两期河流相砂砾层分布的差异反映了古河道在晚更新世海侵后、全新世海侵前所发生的变迁。这主要是断裂活动的结果。因此，在珠江三角洲的形成和演化过程中。新构造运动既影响着三角洲的沉积又控制着河道的变迁．

Neotectonics of the Pear River Delta and its Relationship with the Deltaic Evolution

Systematical analyses on available data suggest that the tectonic movement of the Pearl River Delta （PRD） is characterized by fault activities and differentiated movements of fault blocks, which has played one of the most important roles in the deltaic development. Most basement faults developed or reactivated during the Quaternary cut the delta area into a series of fault blocks. These fault-blocks moved at different directions and rates but basically were dominated by subsidence, providing accommodation for sediments. Thus, the Quaternary sedimentation of the delta plain was mainly fault-controlled in the evolution process of the PRD, for which many evidences have been obtained from the Quaternary sediment distribution, drill holes and geologic profiles. In addition, different distribution of fluvial gravels formed before and after the first transgression of the Late Quaternary suggests that the paleo-drainage pattern had been significantly changed, which was mainly the result of fault activities. Since the Holocene, neotectonic influence on channel development has become less significant as fault activities getting weaker.