广西灵山断裂带构造演化特征浅析

A PRELIMINARY ANALYSIS OF THE TECTONIC EVOLUTION OF LINGSHAN FAULT ZONE,GUANGXI

本文以构造解析理论为指导,结合前人资料和野外地质考察,将广西灵山断裂带的演化期分为加里东-海西期、印支期、燕山期和喜马拉雅期。加里东-海西期:灵山断裂带所处的钦州—防城地区表现为连续沉积,海西期末发展为裂陷槽;印支期:随着杨子板块与华夏板块发生斜向碰撞,形成了灵山断裂带,该断裂带平面上呈现4-6条平行断层束,剖面上呈现正花状构造;燕山期:在花岗岩浆大规模侵入下,导致灵山断裂-褶皱带被巨大岩基占据和分割;喜马拉雅期:受青藏高原隆升影响,灵山断裂带复活为右行走滑,并形成拉分盆地,其主断裂的持续右行走滑,导致应力集中,致使广西1936年发生了6.8级大地震。

In this paper,according to the tectonic theory,in combination with the previous information and the field geological survey,the evolution of Lingshan fault zone has been divided into Caledonian-Hercynian,Indosinisn,Yanshanian and Himalayan. In Caledonian-Hercynian,Qinzhou-Fangcheng area of Lingshan fault zone was in continuous sedimentation,the rift was developed in the final period of Hercynian; in Indosinian,the Lingshan fault zone was formed because of the oblique collision of Yangtze Plate and Cathysian Plate. This fault zone shows a fault bundle of 4-6 parallel faults on the horizontal plane,a positive flower structure on the vertical section.In Yanshanian,because of the large scale granite magma intrusion,Lingshan fault-fold zone was occupied and separated by the magnitude batholite. In Himalayan,owing to the rising of Qing-Zang plateau,Lingshan fault zone was revived and became the right-handed strike-slip structure and the tension basin. The continuous right-handed strike-slip of major fault causes the stress concentration and the earthquake（ magnitude 6. 8） in 1936.