A DUCTILE SHEAR ZONE IN THE WENDUERMIAO AREA, NEI MONGGOL （INNER MONGOLIA）

The early Paleozoic plate subduction zone in the Wenduermiao area is composed of a series of E-W-trending high-strain zones, of which the Tulin- kai-Ulan Aobao ductile shear zone is the largest in Scale. Both sides of the She- ar zone are controlled by schistosity-kink boundaries. The strain intensity wi- thin the shear zone increases gradually from both margins towards the center. The greatest value of the strain intensity in the centralpart is 11.34, and ra- pidly and unevenly decreases towards both sou them and northern sides, ranging between 1 and 3. The subduction depth of the plate subduction zone resulted from accumu- lation of the amount of the shear displacements of all the high strain zones, and the results of measurements of the amount of the displacements of five cross-sections in the Tulinkai-Ulan Aobao zone are close, the average value being 5358.9m.