Research On Ductile Shear Zone In Baiyinhaote Inner Mongolia

Baiyinhaote ductile shear zone lies in eastern of the Inner Mongolia.It was discovered and studied in the1:250000regional geological surveyand which take on NNE through the north of Baiyinhaote, extend about8.5kilometer, width about0.7-1.2kilometer. Mylonitic plane attitude of theductile shear zone is quite stabilization, the most direction of tilt isnorthwest. Observation from the whole shear zone,the southern deformablezone is stronger than the northern.There are some structural character in the shear zone，such as the shapeof“σ”rotary fragment，“domino-style” structure，quartz strippedstructure，mechanical twinning，strain shadow. The ductile shear zone showleft-lateral shear on macrocosm and microcosm，therefore, it is the typeof strike-slip shear zone.In the dynamics, we account some stress in the shear zone, theorientation of principal stress is near south-north. We reckondifferential stress by subgrain, which is50.56MPa. We obtain averagestrain velocity by creep equation,which is according to character ofdeformation and EBSD. We think the ductile that formed about10-20kilometers of the earth’s crust.It’s temperature of formation is about500℃,the pressure is about over250-540MPa.According as time of magma, characteristic of deformation, relationof incisionand characteristic of lithogeochemistry, combinedtectogenesis of region, we think this shear zone that formed in lateJurassic epoch to Early Cretaceous Epoch.It may belong to theDaxinganling uplift and the Songliao Basin in the Late Jurassic to EarlyCretaceous tectonic boundaries, and left Nenjiang-Bali rare faultductile shear deep in the Songliao basin reflect common control with theTan Lu fault,the formation and evolution. Although Baiyinhaote ductileshear zone deposits related has not been found, but the ductile shear and brittle-ductile deformation convert the role into gold is closelyrelated, is one of the important tectonic signs to find gold and othermetal ores.