Basement-involved structures: characteristics, styles, mechanism and tectonic settings

The basement-involved structure is predominant in the thick-skinned structure and developed in various tectonic settings, which is not constricted within the peripheral of the active continental margins but also involves the formation of orogenic belts, fragmentation of foreland basins, formation of plateaus, and deformation of cratons. Some of these structures are developed in intracontinental areas far away from active continental margins. There are both links and differences between basement deformation and caprocks deformation in the basement-involved structure, including the thickness of caprocks, pre-existing structures of basement, stress field, rheological differences between basement and caprocks, thickness of caprocks and so on. At present, the formation of basement-involved structures, especially the deformation mechanisms in intracontinental areas, are still unclear, low angle subduction of oceanic plates is considered to be the main pathway leading to long-distance stress transmission. During the Mesozoic and Cenozoic, the Chinese mainland has experienced multiple tectono-thermal events, which are prerequisites for the development of basement-involved structures. At present, typical basement-involved structures have been found in central North China Craton, the Junggar Basin, northern Qinghai-Tibetan Plateau and other regions. Their formation mechanism and setting represent different important continental crustal deformation, including the deformation in the process of plateau formation, the shortening deformation of craton, and the process of gradual fragmentation of foreland areas of orogenic belts. However, the study of basement-involved structures in China has not drawn enough attention, and there is also less profound understanding on the influence of these deformations in the process of continental deformation. Southern China has also undergone significant continental deformation during the Mesozoic. However, unlike Northern China, there are fewer reports and studies on basement-involved structures in Southern China, which may be one of the future research directions.