| Ductile deformation zones, also called high stain zones, exist extensively in the earth from supra-crust to lower crust. They sometimes have two common characters, one is they look like straight lines; another is they have tectonites with high strain. Ductile shear zones in Xihongshanzi of Inner Mongolia are so many, we could divede them into Shasenghao-Xiaodongfang ductile shear zone; Zenglongchang group of Cha'ertaishan group ductile shear zone; E-W ductile shear zone; North West and North East to conjugate small-scale shear zone group. In addition to ductile shear zones of the above,there is a group of "S"-type folding.Shasenghao-Xiaodongfang ductile shear zone mainly developed in Liushugou group of Seertengshan group of Early Proterozoic, which is extending in East-West; Zenglongchang group of Cha'ertaishan group is scattered in the area, there is a ductile shear zone widely developed among the area of the group and adjoined rocks around the group; E-W ductile shear zone is developed along the Xiaobaiyanhua-Dahecheng-Huoshaoyangjuan which are situated in the north of the research zone; North West and North East to conjugate small-scale shear zone group are widely developed in the area, the North West to conjugate small-scale shear zone group which strike during 300°~320°. Their width during 50cm~20m and extending during 1km~8km. Which Cutted and changed a variety of basement rocks and stratigraphic units, to form the muscovite-quartz schist, chlorite-muscovite-quartz schist, hornblende schist, and chlorite- hornblende schist, etc. The North East to conjugate small-scale shear zone group which strike during 50°~60°. Their width during 50cm~50m and extending during 1km~2km. Which are scattered in the area, and they have the same tectonites to the North West to conjugate small-scale shear zone group. As a result of these two sets of ductile shear zone in the tectonites and geological features are basically the same ,so we think they are the conjugate ductile shear zone. According to current research information the Obtuse angle bisector of the conjugate ductile shear zone which representatives of the direction of compressive stress, reflects the results of the direction of NE-SW compression. The features of the North West to conjugate small-scale shear zone are stronger, but the North East to conjugate small-scale shear zone group are weaker maybe means that they formationed in east-west shearing caused deformation of secondary stress field. The stratum and early nearly plane detachment formation structure in the pieces of Cha'ertaishan group were curved and formed the folds, At present, there are better retention of Ganggang fold, Duanyoufang fold and Fushengtai fold . They appear the "S"-type folding group.Near east-west ductile shear zone is the largest shear zones in the area, in order to reveal the causes and dynamics characteristics of it, this article will descript through its spatial characteristics, tectonic features, its kinematics and dynamics characteristics, as well as the electron probe on its analysis, which will ultimately reveal the causes of it and so on.1. The spatial characteristics and tectonic schist of the ductile shear zonesAccording to the pieces of regional Mesoproterozoic Cha'ertaishan group and the tracks of the fold axis in these which appear nearly east-west - north west - nearly north-south - the south-east - nearly east-west, was "S", it maybe the result of the left shear; And the E-W ductile shear zone, the North West and North East to conjugate small-scale shear zone group, the "S"-type folding group, they Constitute a Complex Construction Portfolio, they may form in the tectonic deformation by the left shear. Through these, then according to differential paleostress and strain type which measured by the ductile shear zone around Cha'ertaishan group are the same to the the E-W ductile shear zone's, we could know the E-W ductile shear zone and "S"-type folding group should form in the same shearing stress field, and they are the products at the same time in different parts of the formation of different tectonic.2. The formation of the temperature and pressure environment and the times of the ductile shear zoneAccording to the characteristics of the rock composition, we ultimate choose the method of electronic probe, and we choose the geothermometry of Chlorite-muscovite, finally Determine the metamorphic temperature of the mylonite is around 230℃. We know the measuring of geothermometry of Chlorite-muscovite is lower than the other geothermometries.And the date of electronic probe which we choose is Chlorite-sericite,not Chlorite-muscovite, These two reasons have caused the measured temperature is lower than its original temperature. While this does not reach the temperature range of low-temperature greenschist facies, it still consistent with the ductile shear zones in the area formed in Mylonitization of shallow which is reflected by the tectonic schists.Through the research of the geological relationship between the "S"-type folding group and the ductile shear zones around them, we can know that "S"-type folding group formed after Mesoproterozoic. And because of the E-W ductile shear zone and the "S"-type folding group have the same geological features, we can know they formed in the same stress field. Then , we could know the age of E-W ductile shear zone by the "S"-type folding group.3. The model of the dynamics and kinematics of the E-W ductile shear zoneBecause of tectonic schists are developed in the area ,and we know it forms in the pressing flat environment. So we could know that the ductile shear zone of the area formed in the Squeezing environment, that's the same to the determination of strain type; Through field geological mapping and Identification sheet by microscope, we can also know the ductile shear zone performances for the left shear; Through the Calculation of differential paleostress, we know the differential paleostress of the area during 33.05-37.21 MPa, and the differential paleostress in the north of the area is larger than the south. It follows that the E-W ductile shear zone of the area formed in the environment of nearly press in S-N and shear in E-W, and it's the product of the Mylonitization of shallow.
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