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北京地区云蒙山变质核杂岩在白垩纪阶段抬升的早期,伴随着沿四合堂剪切带由北向南的拆离滑脱和大型花岗闪长岩的垂向侵位,晚期变形发生在花岗闪长岩岩基周边及其邻近围岩中,形成云蒙山剪切带,并伴随大量同构造的花岗岩和伟晶岩岩脉灌入。剪切带中所有的岩脉都随时间发生了不同程度的变形,较老的岩脉形成紧闭的圆柱状褶皱,枢纽与剪切带的线理和面理接近平行。岩脉与剪切带中L-S组构的平行化作用主要是由于这种转动的结果。岩脉的成分和长英指数随它们的变形程度发生变化,说明持续的岩浆分异作用与韧性剪切变形是同时发生的。云蒙山剪切带由岩浆底辟引起的上盘岩石重力所驱动,并不断得到同构造侵位岩脉的补充,起到存储和不断改造侵位岩脉的作用。早期伸展体制下形成的四合堂剪切带局部遭受云蒙山剪切带的改造或复合。该地区的岩石、构造和同构造岩脉的变形几何学和运动学证据表明,太古宙结晶基底的抬升是下部岩浆底辟与上部地壳伸展拆离共同作用的结果。
In the early stage of uplifting of the Cretaceous, the Yunmengshan metamorphic core complex in Beijing area was accompanied by detachment and detachment along the Sihengtang shear zone from north to south and the vertical emplacement of large-scale granodiorite. Late deformation occurred in In the periphery of the granodiorite basement and its surrounding rocks, the Yunmengshan shear zone is formed and filled with a large number of synsedimentary granite and pegmatite dikes. All of the dikes in the shear zone have been deformed to varying extents over time. Older dikes form closed cylindrical folds, and the line and face of the hub and shear zones are nearly parallel. The parallelization of the L-S structure in the dikes and shear zones is mainly due to this rotation. The composition of the dikes and the Changying index change with their degree of deformation, indicating that the continuous magmatic differentiation and ductile shear deformation occur simultaneously. The Yunmengshan shear zone is driven by the gravity of the overlying rocks caused by magmatic diapirism and continually complements the tectonic emplacement dikes to play the role of storage and continual alteration of emplacement dikes. The Sihetang shear band formed under the early extensional system locally undergoes the transformation or compounding of the Yunmengshan shear zone. The deformation geometry and kinematic evidence of the rocks, tectonics and synsedimentary dikes in this area show that the uplift of the Archean crystalline basement is the result of the interaction between the lower magmatic diapirs and the extension and detachment of the upper crust.