沂沭断裂带早期活动讨论

DISCUSSION OF EARLY MOTION ABOUT YISHU FAULT ZONE

沂沭断裂带展布区域内不同地块的变质作用、岩浆活动和构造变形特征表明，在新元古代之前，区内发生过强烈的构造运动，但各地块的构造形迹不是在同一应力场作用下形成的，现存的沂沭断裂带各断裂均为脆性断裂，无继承性活动的迹象。因此，认为沂沭断裂带形成于新元古代之后。

From the characteristies of metamorphism, magmatism and structural deformation of massifs in Yishu fault zone, the authors think that there was a strong tectonic motion occurring before the Late Proterozoic era in the region of Yishu fault zone′s extending, the structural features of different massifs were not formed in the same stress field, the faults located in Yishu fault zone are all brittle ones, none of posthumouse active evidence is found in these brittle faults, and Yishu fault zone formed in the Late Proterozoic era.