Sedimentology, Depositional Systems, and Sequence Stratigraphy of Mixed Fluvial-Eolian-Lacustrine Deposits in an Intracontinental Rift Basin, Bogda Mountains, NW China

The Greater Turpan-Junggar Basin in NW China is a mature petroliferous basin that has been extensively explored and exploited for hydrocarbons. Future development will require a thorough understanding of the basin fill and evolution. However, the complexity of the basin fill, with abundant erosional surfaces and regional thickness and lithological changes, creates a challenge for such understanding. The study focuses on the sedimentology, environmental interpretation, and sequence stratigraphy of mid-Permian (Capitanian) fluvial-eolian-lacustrine deposits of the Quanzijie Formation exposed in the Bogda Mountains. These superbly exposed strata offer a unique opportunity to interpret the processes and factors controlling basin filling, such as tectonics, climate, provenance, and conditions of the catchment basin. Five complete stratigraphic sections of the Quanzijie Formation have been measured in the southern and northern slopes of the Bogda Mountains. Sedimentary processes vary greatly between the two areas; fluvial-eolian deposits dominate in the south, and fluvial deposits dominate in the north. Nevertheless, both areas recorded similar tectonic and climatic changes. Evidence from sandstone petrography suggests that the two areas had different provenance based on compositional variations. However, detrital zircon age dates suggest a similar provenance for the two areas. Additional petrographic and geochemical data is needed to understand the roles of provenance, tectonic, climatic, and depositional processes in the deposition of Quanzijie. The strategies developed in this study will be used to understand the evolution of the Greater Turpan-Junggar basin and other similar basins around the world