肥东低角度韧性剪切带内岩石变形特征

Rock deformation characteristic of low-angle ductile shear zone of Feidong

肥东低角度韧性剪切带紧邻郯庐断裂带巨大的近直立的左行平移韧性剪切带发育,其岩石变质变形特征具有韧性剪切带的一般特征,即越靠近剪切带内侧,岩石变质变形程度越强,远离韧性剪切带,岩石变质变形强度越弱。低角度韧性剪切带内超糜棱岩变形强烈,变质相可达到角闪岩相,其变质变形程度与直立的郯庐断裂带内超糜棱变质变形程度类似,两者在形成环境和成因类型上统一,具有大陆岩石圈被高角度韧性剪切带切割并沿低角度韧性剪切带逆冲推覆的形成机制。

The low-angle ductile shear zone of Feidong developed next to the huge suberect sinistral ductile shear zone of the Tan-Lu fault zone, its rock metamorphism and deformation characteristics corresponded with the general characteristics of the ductile shear zone, i.e. the closer it was to the shear zone inside, the stronger the rock metamorphism and deformation were, and the farther it was away from the ductile shear zone, the weaker the metamorphism and deformation strength were, Ultramylonite deformed greatly in low-angle ductile shear zone, the metamorphic facies reached to lower amphibolite facies, and the deformation and metamorphism degree were similar to those of ultramylonite in the erect Tan-Lu fault zone. Both were unified in the forming environment and genetic types, and the forming mechanism was that continental lithosphere was cut by high-angle ductile shear belt and thrust nappe formed along low-angle ductile shear zone.