大型断裂系统在古板块研究中的意义──以中亚地区为例

中亚地区由西伯利亚、哈萨克斯坦—准噶尔、塔里木等三个古板块构成。研究发现，三个古板块均对应着各自具有特征的大型断裂系统．后者的表现是：各断裂系统中主要的一组断裂与对应的古陆缘平行，而次要的一组断裂与对应的古陆缘垂直或呈大角度斜交，也表现在每个大型断裂系统内部运动学的协调性。本文还讨论了大型断裂系统的研究在古板块划分、恢复古板块之间的相对运动特征和复原古板块原始形态三方面的意义。

TECTONIC SIGNIFICANCE OF LARGE FAULT SYSTEMS TO THE STUDY OF PALEO-PLATES

The area of central Asia is composed of three paleo-Plates: the Siberia, the Kazakhstan-Jungar and the Tarim.Each paleo-plate has its characteristic large fault system and each system,in turn,includes two sets of faults.The first set,which is of major importance,runs parallel to the margin of the ancient continent,whereas the second set is always approximately perpendicular to the ancient continental margin.The internal features of every system exhibit much harmony during their evolution.These faults have evolved through two stages.The first stage,which is characterized by the formation of ophiolite or ophiolitic melange belts,corresponds to the disintegration of the continental crust.In contrast,the second stage coincides with the collision of paleo-plates.It is beyond doubt that the faults which was developed at the first stage have suffered intense reformation. It is concluded that the geometric relations between the large fault systems and the ancient continental margins are produced by an integration of continental disintegration and divergence, convergence and collision of moving plates. Significance of large fault systems is also discussed in terms of the division of paleo-plates, the discrimination of their relative motion and the recovery of their primitive geometry.