THE CHARACTERISTIC FEATURES OF LATE HERCYNIAN-INDOSINIAN TECTONIC ACTIVITIES OF THE LEFT SONID BANNER AREA,INNER MONGOL AUTONOMOUS REGION

The region of Left Sonid Banner of Inner Mongolia is located in the Xing-Meng fold zone of the northern rim of the North China Plate.A comparative study of the shapes of the ENE-trending folds,the causative axial loading and the resulting shortening as well as the geometry of the faults and ductile shear zone has been made.And the strain sequence is thereby established.As a result there has been distinguished Indosinian tectonic features produced on the foundation of the late Hercynian strucures by progressive deformation under the same ensueing stress field.