Spatial distribution of the lithospheric density structure in three large cratons in China based on GOCE gravity gradient data

Abstract

The long-term stability of continental cratons can prevent them from being transformed by tectonic processes, such as late-stage plate subduction and convective erosion. This stability is closely related to their unique material composition and lithospheric root structure. The tectonics of China exhibit distinct features compared with those of other regions in the world. Studying the lithospheric density structure of the three large cratons offers an effective approach for understanding the dynamic mechanisms involved in the evolution of China continental cratons. Gravity observations are sensitive to density changes. In this study, after the GOCE satellite gravity gradient data in China and adjacent areas are processed, the methods of boundary identification and depth imaging are combined to effectively obtain the spatial distribution of the lithospheric density structure. The horizontal and vertical distributions of detailed structural lithospheric features in three large cratons in China are obtained. The results indicate that the North China Craton (NCC) has experienced destruction in both the north–south and east–west directions. The boundaries of the suture zone in the southern South China Craton (SCC) are consistent with the structural lines and are more oriented towards the eastern side of the Jiangshan Shaoxing Fault in the eastern SCC. At the southern edge of the Tarim Craton (TC), the features of the spatial distribution of density do not indicate southwards movement of material. With the features of the spatial distribution in three large cratons in China, the features of the distributions in three large cratons are compared, and the reasons for the dynamic mechanism are further analysed and summarized.