黔城推覆体群的形态、结构和运动学特征

在华南中、新生代红盆中存在一系列由元古宇 -古生界地层组成的地质体 ,突起于红盆之中。许多学者对其成因进行了研究 ,得出了不同的结论。笔者对沅麻盆地南段主体由板溪群、震旦系组成的黔城推覆体群进行了研究 ,认为其成因与印支期以来川、黔、湘地区存在的、由南东向北西推覆的区域性构造事件有关 ,其形态、结构与国内外许多典型的推覆结构有相似之处。该推覆体由数条撕裂断层分为几个叠瓦体 ,各有不同的形态、结构特征。本文用被动顶板双重构造模式来解释该推覆体群的运动学模式 ,并据该区的地质特征对经典的被动顶板双重构造模式进行了补充。

CHARACTERISTICS OF SHAPE, STRUCTURE AND MOVEMENT OF THE NAPPE GROUPS IN QIANCHENG

There have been developed a series of geological bodies consisting of Proterozoic\|Palaeozoic layers in Mesozoic\|Cenozoic basins in Hunan. Many schoolars studied their formation mechanism and drew different conclusions. The authors have studied the Qiancheng nappe group consisting of the Banxi Group and the Sinian system, and suggest that the mechanism of formation is related to regional tectonic events (thrusting) from southeast to northwest in Sichuan, Guizhou and Hunan from Indo\|Sinian movement. The shape and structure of the Qiancheng nappes can be compared with those of many famous nappes in the world. This nappe group is divided into several imbricates by several tear faults, each of which has different features with respect to its shape and structure. The authors explain its kinematic model with the passive roof duplex and enrich the classical passive roof duplex according to the geological features of this area.