曼洞断层与牛角塘断层的主要特征及两者关系探讨

A Structural Analysis of Development of the Mandong Strike - Slip Fault Superimposed on the Niujiaotang Fault in Southern Guizhou

曼洞断层是燕山期形成的且具多级断坪和断坡的逆冲断层，也是贵州东南部规模最大的逆冲断层。在其形成的早阶段，以加里东期形成的牛角塘断层的NE段为滑动面，自SE向NW逆冲，形成道冲断层；晚阶段，牛角塘断层的NE段则成为其上盘走滑断层的走滑面，并与牛角塘断层的SW段连为一体，形成NE—SW向的走滑断层，同时切割曼洞断层。

The Mandong fault, a largest northeast - striking thrust throughout southeastern Guizhou, is characterized by mu1tiflat and multiramp. The authors' studies show that the fault may have experienced two phases of development: the first phase when the fault developed from the northeastern segment of the Caledonian Niujiaotang fau1t and then thrusted to northwest by employtng the Niujiaotang fault as its sliding surface; and the second phase in which a strike - slipping motion of the hanger of the Mandong fault took place along the northeastem segment of the Niujiaotang fault.