祁连造山带特征及其构造演化

祁连造山带的范围及构造单元经重新厘定和划分，其南界扩展至昆中断裂；解体了走廊过渡带；扩大了中祁连，相应缩小了南祁连范围；新划出乌兰大坂—拉脊山和柴达木周缘南北链状断陷带；确定北祁连属于柴达木—中祁连地块与阿拉善地块间的陆间裂谷。并运用断块学说对其多旋回构造演化作了分析，本区始生代—古生代属于塔里木—中朝地块南部大陆边缘断陷—焊接造山作用体制。中新生代，在古亚洲构造域、特提斯—喜马拉雅构造域和滨太平洋构造域“品”字型动力体系作用下（尤以前二者为主），转化为陆内浅层断（拗）陷—逆掩叠覆造山作用体制。应力作用方式从早到晚由顺时针直扭向旋扭转化。二者既有继承又有新生。挽近时期，在印度地块挤压动力体制下卷入青藏高原陆内汇聚作用，产生大幅度断块隆升、盆地沉陷，造就了现今高原盆岭景观

THE FEATURES AND TECTONIC EVOLUTION OF THE QILIAN OROGENIC BELT

This paper re classified the scope and tectonic units of Qilian orogenic belt.So its south boundary was extented to central Kunlun fault;the transition belt of corridor was disintegrated;the central Qilian scope was enlarged,and south Qilian scope was reduced correspondingly;Wulandaban-Lajishan and the northern and southern chain like fault depression belt of surrounding Qaidam was determined newly;north Qilian is determined to be characterized by intercontinental rift between Qaidam central Qilian massif and Alxa massif. According to fault block theory the writer analysed its multicycle tectonic evolution and considered that this region to be characterized by system of the south epicontinental fault depression welding orogeny of Tarim-Sino Korean massif from Eozoic to Paleozoic.In the Mesozoic and Neozoic this system were changed to system of intercontinental shallow fault depression-thrusting overlaying orogeny under joint dynamic system processing of Paleo Asiatic tectonic domain,Tethys Himalaya tectonic domain and Marginal Pacific tectonic domain(especially the former two).The mode of stress process was transformed from clockwise linear shearing into rotation and shearing from early to late.Both modes are succession as well as rebirth.In neoid period,this region involved in intercontinental convergent process of Qing Zang Plateau under the dynamic system of compression of India massif to result in big fault block uplifts and basin depression, forming nowadays landscape of plateau,basins and mountains.