辽东滑移构造宏观特征

展布于辽宁东部鞍山—本溪间的寒岭—偏岭断裂走向为北东东,延长大于200km,运动方向为左行走滑,形成于中生代晚期,与之同期的本溪思山岭—塔子岭—三家子—大卫村屯断裂走向北东,延长140km,运动方向为右行走滑,两者同属于区域性地壳-岩石圈型断裂。研究证明,两者夹持的楔形断块体西起鞍山、海城、营口一线,东至本溪市,是一个陆内滑移造山带,最大滑移距离达37km。本溪市上卧龙—兴隆山断裂走向北西—南东,延长10km,则是其前缘挤压带。这一构造的形成与东亚大陆在中生代以来呈断块状向太平洋扩张有关,与壳内花岗岩质层的水平变异有关,与下辽河断陷内基底层次的侧向伸展力有关。滑移主体以斜切凤城凸起和太子河凹陷,改造着区域构造格架,在其影响区域内形成一个滑移构造体系。对此滑移构造体系的识别与建立,对研究上述地区晚中生代以来地质构造演化、找矿、找水及评价地壳稳定性都有重要意义。

MACROSCOPIC CHARACTERISTICSOF LIAODONG GLIDING STRUCTURE

From Anshan to Benxi in the east of Liaoning,Hanling-Pianling fault and Sishanling-Taziling-Sanjiazi-Daweisuntun fault are synchronous in the late stage of Mesozoic and both belong to regional crust lithosphere type faults The former is NEE trending and left lateral strike slipping with more than 200 km of extension,but the latter is NE trending and right lateral strike slipping with 140 km of extension A wedge shaped fault block body is sandwiched by above two faults,which is an intracontinental gliding orogenic belt,west from Anshan-Haicheng-Yingkou,east to Benxi,with the largest slip of 37 km There is anothor fault,which is a frontal compressional belt of the edge shaped body,with NW-SE strike and 10 km of extension The forming of the edge shaped body is related with the spreading of East Asia continental to Pacific Ocean since Mesozoic,also with the horizontal variation of granitic layer in the crust, with the lateral extension in the basement of Xialiaohe fault depression The gliding body obliquely transects Fengcheng uplift and Taizihe depression,reforming the regional tectonic framework into a gliding structure system The recognition and establishment of the gliding structure system have important significance in studying the geological tectonic evolution since Late Mesozoic,in ore and water prospecting,and in valuating the stability of the crust in the above mentioned areas