RESEARCH OF INDOSINIAN CRUST STRUCTURAL DEFORMATION AT YINSHAN AREA
LIU Zhenghong,XU Zhongyuan(College of Earth Sciences, Jilin University, Changchun130061, China)
Yinshan locates western Yinshan-Yanshan Mesozoic intracontinent orogenic belt. Crust structural deformation was dominant of south-north horizontal compression deformation mechanism during Indosinian episode. It had been formed a series of east-west direction large folds and thrusts which is the main structural outline of Yinshan Mesozoic orogenic belt. According to the sedimention, magma activity and the modified and superimposed relationship among different structural elements, Indosinian episode crust structural evolution can been divided into three stages. The early one is sedimention of small intermountain basin which accumulated continental detrital formation and volcanic deposition formation. The middle one is folding stage which formed Daqingshan compound sycline and tight isoclinal fold. The thrusting process happened in late stage and formed large thrust napes acompanying strong magma activity.