| The structure location of Alxa Youqi Tamusu Township located in the northern west-middle section, identified AErGaShun ductile shear zone which was nearly EW, in the study of 1:5000 regional geological survey and tectonic Profile.On the basis of structural analysis, microstructure, stress analysis of ancient, isotope-dating etc, the system study on ductile shear zone shows: the present in the plane of the arc protruding southward, mylonitic foliations general strike north,and in central and north deformation relatively strong.Structural phenomenas in the shear zone,including rotational porphyroclast and"domino"structure ,indicate the motion feature is profile extension.Mineral thermometer, EBSD fabric analysis for quartz, Two-feldspar Geothermometer, The determination of stress reflect the ductile deformation temperature at more than 500℃, pressure at 300～400MPa, amount to amphibolite facies and at middle-shallow tectonic level. The differential stress values are estimated at 97.6～123.1 MPa, strain rate is 10-15 s-1(400℃) and 10-13 s-1(500℃).Ductile shear zone developed in porphyaceous adamellite in the middle Permian and was intruded by dioritein in the lower Permian, therefore the formation time of the ductile shear zone limits between 257Ma to 264Ma.
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