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糜棱状花岗岩是研究核杂岩运动学、动力学和年代学的理想标志体.它们呈线型平行主期伸展面理展布,去应变后,初始形态轴比也近席状.岩石具典型的S-L和L组构,变形类型以单剪为主,纯剪次之.多种剪切标志指示上盘向南南东剪切,反映了核杂岩的运动学特点.不同岩体变形强弱差异有别,但面线产状一致,显示了递进的韧性剪切作用,其组构发育机制具有(亚)岩浆流动机制→高温固态流动→中低温固态流动连续过渡特点.上述特征显示,该类岩体是同伸展构造早期岩体的可能性较大.结合年代学研究,揭示该区在早中生代中下地壳可能发生伸展变形.
The mylonitic granite is an ideal marker for studying the kinematics, dynamics and chronology of core complexes, and they are linearly spread in parallel to the main phase of extensional distribution, and after de-straining, the initial axial ratio is also nearly malleable. Typical SL and L structures, the type of deformation is dominated by single shearing and pure shearing. A variety of shear signs indicate that the upper plate shear south-east, reflecting the kinematic characteristics of the core complex. The differences of strength and weakness are different, but the occurrence of face line coincides with that of progressive ductile shearing, and the mechanism of its structural development is characterized by (sub) magmatic flow → high temperature solid state flow → medium-low temperature solid state flow and continuous transition. It is shown that this kind of rock mass is more likely to extend the tectonic early rock mass.According to the chronological study, the extensional deformation of the middle and lower crust may occur in the area during the early Mesozoic.