祁连山地区大地构造演化及其性质特征

GEOTECTONIC EVOLUTION AND ITS CHARACTERISTICS IN QILIANSHAN REGION

祁连山地区大地构造演化历经了元古代至早古生代的地槽阶段、晚古生代的地台阶段和中、新生代的地洼阶段。地槽阶段元古代为陆块奠基、成长和扩展时期，早古生代为洋壳化板缘构造活动和陆间碰撞构造作用时期。地台阶段大型沉积盆地发育。地洼阶段以陆内造山－造盆作用和块断推覆构造活动为特征。祁连山地区遭受了三次不同性质的造山作用：元古代未托莱运动的陆块挤压褶皱造山作用、加里东晚期祁连运动的陆间碰撞造山作用和中、新生代的陆内块断造山作用。由上，祁连山及其邻区的构造单位由北至南划分如下：（１）走廊地洼；（２）北祁连地穹；（３）中祁连洼陷；（４）南祁连地穹；（５）柴达木地洼。

In geotectonic evolution Qilianshan region has gone through geosynclinal stage from Proterozoic to earlier Palaeozoic era, platform stage in latter Palaeozoic era and diwa stage in Meso-Cenozoic era,Proterozoic era of geosynclinal stage is the period of foundation , growth and development of landmass. Earlier Palaeozoic era is the periods of plate margin tectonism of crust-oceanization and intercontinental collision tectonism. Large sedimentary basins are developed in the platform stage. Intracontinental orogenesis and basin-making prossesses, and block-faulting nappe tectonism are structural features in the diwa stage.Qilianshan region has been undergone three importent orogenesises of different natures:compression-folding orOgenesis of landmass of Tuolai orogeny in last Proterozoic era, intercontinental collision orogenesis of Qllian otogeny in latter Caledonian period and intracontinental block-faulting orugenesis in Meso-Cenozoic era.From the above it can been seen that tectonic units of Qllianshan and its adjacent regions are divided from north to south into following: Zoulang diwa, North Qilian geodome, Centre Qilian depression, South Qiliang geodome and Qaidam diwa.