格尔木─额济纳旗地学断面地体构造的古地磁学研究

THE PALEOMAGNETIC STUDY OF TERRANE TECTONICS IN GEOSCIENCE TRANSECTION FROM GOLMUD TO EJIN QI

给出了格尔木－额济纳旗地学断面及其邻区的２３个古地磁新数据，为该区地体构造的划分提供了古地磁证据．提出北山北部地体属于哈萨克斯坦板块的东延部分，探讨了该板块晚古生代的逆时针旋转运动．分析了塔里木板块的演化特点，该板块大约于泥盆纪通过顺时针旋转运动与哈萨克斯坦板块对接拼合．应用多个参考点古纬度资料研究板块运动特征的方法，分析了断面域及其邻区地体构造的演化过程．研究发现了北祁连地体的古生代南向位移事件，系统地描述了南向位移的演化过程，并探讨了这一事件的地质意义．

On the basis of previous work,23 new paleomagnetic data are obtained which supply a firm evidence for terrane recognition and understanding the evolution history of terranes in the geoscience transection.The paleomagnetic data indicate that the North Beishan terrane belongs to Kazakstan plate while the later exhibits obvious anti-clockwise rotation.Southward movement of Qilian terrane has been recognized through detailed examination of its evolution process.The authors developed a new method of studying the kinematic feature of plate(or terrane)by utilizing several reference points.The kinematic feature of Tarim plate and its collision with Kazakstan plate have been successfully analyzed by applying this method.The reasonabeness and efficiency of the new method have been proved by comparison with traditional method.A tectonic model for terranes in the transection corridor and adjacent region is given in the paper.