应用卫星数字图像研究达拉布特断裂

A PRIMARY STUDY OF THE DARABUT FAULT THROUGH SATELLITE DIGITAL IMAGE

通过对卫星数字图像的解译和地质特征的研究，提出了呈北东向横贯于西准噶尔的达拉布特 断裂是一长达４８０ｋｍ具多期活动的大断裂带。 该断裂对下石炭统及其以前的地层无任何控制作用，只可见左行错断；对中石炭统到下、中 侏罗统的地层具有明显的控制作用；达拉布特超基性岩带中的超镁铁岩体是受推覆构造的影响而 就位于达拉布特断裂的上盘。 本断裂带的形成发育是由于早石炭世以后，碰撞后的西伯利亚、哈萨克斯坦和塔里木三大陆 块仍在不断地相向运动，作为一种应力的释放形式，其早期以左行陡倾的走滑断层形式开始形 成；中期（三叠纪──早、中侏罗世）受陆内俯冲作用的影响，被强烈的推覆构造改造成上陡下 缓的犁状断层；挽近时期，断裂处于引张状态，表现为上盘下降的正断层性质，形成目前表现明 显的断层地貌。

The Darabut fault appeared in the northeast strike across the West Jungger area is regarded as a big multiphase fault with a length of 480 kilometers through the interpretation of satellite digital image and the study of geological character. The Darabut fault does not control the strata of the lower Carboniferous and Precarboniferous Series, only leftlateral breaks can be seen; It obviously controls the strata of the middle Carboniferous and the lower-middle Jurassic ones ; Ultramafite in the Darabut ultrabasic rock is affected by the nappe tectonic, and then it locates in the up side of the Darabut fault. The formation and development of this system resulted from the continuous face-to-face movement of the Talim, Sibelian and Kazakhstanian continental segments after their collision and the early Carboniferous Epoch. As a type of the stress relief form, at the early stage (Triassic period, early and middle Jurassic Epoch) the system was turned into the plough-shaped faults by the strong nappe structure under the continental diving. At the late stage, it was in the state of extention, thus showing that the hanging wall went down. So the clear fault geomorphologic expression has been formed at pre- sent.