新生代广西断裂活动特征及其构造背景

The Cenozoic Activity Characteristics and Tectonic Setting of the Faults in Guangxi

广西境内发育多条北NE和NW向的深大断裂带,它们共同构成了广西X型断裂体系,这些断裂与广西的地震活动可能有着内在联系。系统介绍了广西X型断裂体系主要断裂新生代活动特征,并结合历史地震和广西周边活动块体的运动特征,探讨了新生代期间广西境内断裂活动的构造动力学背景。分析表明新生代广西境内的NW和NE向断裂的活动分别受印支块体、川滇板块的挤出运动和菲律宾海板块与欧亚大陆板块不均匀挤压碰撞作用控制。同时,两组断裂的交汇部位是多个块体/板块作用聚集之地,是应力集中和断裂闭锁的多发部位。

The X shaped fault system developed in Guangxi that consists of a number of NW and NE deep faults is highly related to the generation and occurrence of earthquakes in Guangxi.This paper systematically introduces the Cenozoic activity characteristics of the X shaped fault system,and discusses its tectonic dynamic background based on the historical earthquakes and the movement characteristics of the active blocks around Guangxi.In Cenozoic,the NW and NE faults in Guangxi were controlled by the extrusion movement of Indosinian block,Sichuan Yunnan block and the heterogeneous extrusion collision of Philippine Sea plate and Eurasian continental plate,respectively.At the same time,the intersection of the two groups of faults,where is affected by all blocks/plates,is the frequent site of stress concentration and fault locking.