华北克拉通中生代伸展构造研究的几个问题及其在岩石圈减薄研究中的意义

Some problems in the study of Mesozoic extensional structure in the North China craton and its significance for the study of lithospheric thinning

总结了华北克拉通及周边以变质核杂岩和穹隆为代表的伸展构造研究的进展和存在的问题,提出了值得进一步研究的几个重要问题及其在华北克拉通破坏和岩石圈减薄研究中的意义。以变质核杂岩和穹隆为窗口,开展推覆向伸展的转化机制、区域性伸展运动学特征、剪切应变类型、伸展构造发育的时间和过程的研究,有助于深入探讨增厚地壳向伸展减薄转化的起因和过程,确定减薄的区域运动学方式及时限,查明伸展构造变形对地壳及岩石圈减薄的贡献。这方面的研究将提升华北伸展构造研究的水平,有助于查明岩石圈减薄的地壳响应,为探讨华北克拉通破坏和减薄的时限、机制、模式及深部动力学问题提供直接的构造证据。

This paper summarizes the progress and problems in the study of the extensional tectonics represented by metamorphic core complexes and domes in the North China craton （NCC） and its surrounding areas and suggests some important subjects that merit further study and their significance in the study of the destruction and lithospheric thinning of the NCC. Carrying out studies of the mechanism of transition from thrusting to extension, regional extensional kinematics, shear strain types, timing and process of extension by taking metamorphic core complexes and domes as the window is conducive to probing into the origin and process of the transition from crustal thickening to extensional thinning intensively, determining the regional kinematic manner and timing of crustal thinning and ascertaining the contribution of extensional deformation to crustal and lithospheric thinning. These studies will improve the level of research on the extensional tectonics of the NCC and help to make clear the crustal response to the lithospheric thinning. Particularly, these studies will provide strong evidence for the study of the timing, mechanism, model and deep dynamics of destruction and lithospheric thinning of the NCC.