Xinjiang Ruoqiang Baishan Region Analysis Of Characteristics Of Deformation Of The Ductile Shear Zone

The Baishan area of Ruoqiang County in Xinjiang is located at the northeastern edge of the Tarim plate,and is located at the core of the Paleozoic rift zone of the Beishan area.There are three ductile deformation belts in the study area: one is located within the Baishan fault,and the weakly metamorphosed and strongly deformed Shibanshan Formation is widely developed in the belt.The deformation gradually weakens from south to north;one part exists in the southern part of the Baishan fault.Inside gabbro,another part of the body of strastamite in the southern part of the Baishan fault.Through field geological mapping,field surveys,and measured tectonic profiles of the ductile shear zone in the Baishan area,including the collection of typical tectonic photographs and important structural elements(such as grain and lineage)in the ductile shear zone.In combination with the analysis of the EBSD quartz group composition and structural analysis methods,we conducted a relatively fine anatomy of the ductile shear zone in the Baishan area and obtained the following understandings:(1)Three ductile shear zones were determined in the Baishan area: two were respectively developed in the plagiogranite body and gabbro body in the southern part of the Baishan fault,both of which were oriented toward the NNW,with a width of tens of meters to several hundred meters.Between 5-10 kilometers in length,with a crescent-shaped hook profile.The tectonic orientation is between 160°-340°,the dip angle is between 65°-81°,and the line NWW-SWW is 56°-82° tilting;the other developed within the Baishan fault,the direction of NEE,1-1.5 km wide,tens of kilometers long,across the entire study area,the edge of the tectonic orientation between 160 ° ~ 177 °,344 ° ~ At 354°,the dip angle is between 60° and 88°,and the lineage NEE is inclined between 3° and 20°.(2)Kinematics of ductile shear zone: According to its plagiogranite body,globular body's globular quartz rotating swarf,asymmetrical shearing small folds,book oblique structure,S-C structure,etc.The kinematics is directed to the right;while in the ductile shear zone of the Baishan fault,there are quartz feldspar swarf,book oblique structure,and asymmetrical shearing small folds,and the kinematics are judged to be left and right.(3)Deformation times of the ductile shear zone in the Baishan area: According to the analysis of the data of field veins and rock masses in the field,the presence or absence of mylonitization,and data analysis on the zircon dating of dykes and rock masses.The time of ductile deformation in the right row is Early and Middle Permian(291-271 Ma);the time of ductile deformation in the left row is <271 Ma.(4)Analysis of EBSD quartz structure in Baishan fault: the right tough deformation environment is high temperature(>650°)?middle high temperature(650°-550°);the left tough deformation environment is medium and low temperature(450°-350°)? Low temperature(<350°).(5)The structural division of the ductile shear zone in the Baishan area: There are three structural stages in the ductile shear zone in the Baishan area,ie,early ductile extrusion deformation,mid-range ductile shear-slip shear deformation,and later brittle deformation.