珠一坳陷番禺4洼新生代断裂特征及其区域动力背景

Cenozoic faults characteristics and regional dynamic background of Panyu 4 sub-sag,Zhu Ⅰ Depression

运用丰富的三维地震资料,通过断裂体系静态刻画和动态分析,对番禺4洼断裂发育的时空差异性及构造转型机制进行研究。结果表明:受控于滨(环)太平洋、特提斯-喜马拉雅两大构造域的区域演化背景,番禺4洼新生代断裂体系发育时空差异性明显;拉张裂陷期(E2w—E2e)经历了由NE向断裂控洼到NWW、近EW向断裂控洼的转变,裂后拗陷期(E3z—N1z—N1h)断裂活动减弱、消亡,构造活化期(N1y—Q)表现为先期发育的NWW向、近EW向断裂复活和新的近EW向断裂的产生,且走滑特征明显;现今断裂体系特征体现了多期构造运动的叠加效应。

Using abundant 3D seismic data, this paper analyzed the static and dynamic characteristics of the fault system of Panyu 4 sub-sag, and then studied its spatio-temporal differences and the mechanisms of the structural transformation. The results show that the development of the fault system in Panyu 4 sub-sag is mainly controlled by the regional evolution of the Circum-Pacific and the Tethyan-Himalayan tectonic domains, and its spatio-temporal differences are also significant. During the rifting stage （E2 w-E2 e）, the strike of the strongly active sag-controlling faults changed from NE to NWW and subparallel EW. During the depression period （E3 z-N1 z-N1 h）, the activity of those faults decreased and stopped. In the tectonic activa-tion stage （N1 y-Q）, the above NWW and subparallel EW pre-existing faults were reactivated and some new subparallel EW faults were developed with significant characteristics of strike slipping. At present the fault system characteristics reflect the superimposed effects of multistage tectonization.