郯庐断裂带的主要特征与性质讨论

THE MAJOR FEATURES AND THE NATURE DISCUSSION FOR THE TAN ─LUFAULTZONE

本文在系统分析研究郯庐断裂带主要特征及其两侧变质岩层的延伸和运动方位的基础上，认为该断裂带两侧地质体的“左行平移”位错效应，是与华北地块南缘为向南凸出的弧形构造，以及在华北与扬子两地块聚合时发生巨大的逆时针旋转运动有关，郯庐断裂带既不是左行平移断层，也不是转换断层，而是发生于大别一苏鲁变质造山带弧形转折部位的基底断裂。中侏罗世后，发展成具多期活动的早期夭折型裂谷特征的地堑型断裂构造。

This paper,on the basis of systematic analysis of the major features of Tan─Lu Fault Zone and theextension and movement direction of metamorphic rock beds on both sides of it, suggests that the left─later-al displacement effect of the geological bodies around the fault is related to the fact that the southward con-vexing arc─structure of the south marginaI North China Plate took a giant counter─clockwise rotation whenit converged with the Yangtze Plate. The Tan─Lu FauIt Zone is a basal fault taking place in the arc─liketurning part of the Dabie─Sulu metamorphic orogen rather than a left─lateral displacement fauIt or a trans-form fault.It has since mid─Jurassic developed into a graben─type falt structure with the characteristics ofsomewhat die─young─type rift of multi─stage activities.