庐山变质核杂岩具有典型的3层结构.拆离带是核部隆升过程中盖层滑脱、剪切变形而形成的,该拆离面是在北东向褶皱基础上叠加杂岩核部隆升作用而形成的波状起伏面.拆离带在核部以西发育倾向西向、南西向、北西向的面理和矿物生长线理,显示向西滑脱形成剪切拉伸变形的特征.拆离带岩石以糜棱岩和构造片岩为主,辅以碎裂岩和构造角砾岩.岩石变形特征表明其既具有韧性变形,也具有脆—韧性变形及脆性变形的特点.核部隆升引起的拆离变形作用,不仅形成了拆离带,还影响了拆离带以上盖层岩石,形成一个由拆离带向上由强变弱的变形域.这种规律性递变现象使庐山变质核杂岩具有垂向变形分层、水平变形分带的特点.拆离带中角闪石—斜长石矿物对计算得出的变质温度为653 ℃~694 ℃,压力为0.56~0.67 GPa.
The Lushan metamorphic core complex has a typical three-layer structure. The detachment belt is formed because of slip of the cover and shear deformation during the uplift of core. The detachment surface is undulating because of the uplift of the core complex which is superimposed on NE-trending folds. In the west of the core, foliation and mineral lineation are developed with dip direction of W ,SW and NW ,which indicated the cover slipped to the west and then formed the shear tensile deformation. Rocks in the detachment belt are mainly of mylonite and tectonic schist, supplemented with cataclastic rock and structural breccia. The deformation characteristics indicate that the core complex rocks are in middle-deep tectonic environment with plastic deformation at the early stage of uplift. With the continuing of uplift, the deformation domain gradually became brittle-plastic and finally brittle in the shallow environment. The detachment deformation not only formed detachment belt, but also affected the overlying strata and formed a upward deformation domain from stronger to weak. This regular change indicates that the deformation of the Lushan metamorphic core complex has vertical stratification. The temperature and pressure calculated by amphibole-plagioclase geothermobarometer are 653 ℃-694 ℃ , 0.56 -0.67 GPa respectively.