关键词: 广东, 第四系, 地貌, 断裂活动性

Abstract: Activity and neotectonics of the Shenzhen fault zone in the Shenzhen Special Economic Zone,Guangdong Province,has been discussed on the basis of geomorphic features and Quaternary sediments,as follows:1. There is a series of the smaller intermontane basins and valleys,with axis orientation of NE-SW or ENE-WSW same as trending of the major faults within the fault zone. Most of these basins and valleys,in which the colluvium,alluvium and swamp deposits,with a total thickness of less than 10-15m,were accumulated during the period from the middle of the Late Pleistocene to the middle of the Holocene,are located in the older fracture and or the limistone strata undergoing karstification strongly. Their distribution,hence,might be related to the faulting processes before the Late Pleistocene. However,any fault and marked deformation in the sediments of the Late Pleistocene and Holocene has not been observed. It may be suggested that no remarkably faulting has occurred in the fault zone at least since the middle of the Late Pleistocene.2. Four paleo-denudation surfaces and three alluvium tarraces have been developed in the fault zone since about 1.8 Ma. The vertical deformation rates of crust uplift relative to the regional erosion basis could be estimated as 0.04-0.2mm/a for different ages,based upon the elevations and duration estimates of the geomorphic surfaces formed in different stage. The Quaternary tectonic movement would be characcterized by pulse uplift and depression of the crust for the Shenzhen fault zone.

Key words: Guandong, Quaternary deposits, Geomorphology, Fault activity