Response of source-to-sink patterns during the Mesozoic to tectonic setting in southwestern Tarim Basin: Insights from detrital zircon geochronology and morphology

Multiple Mesozoic tectonic movements in the southwestern Tarim Basin led to the change of accommodation space caused by tectonic setting switch, which resulted the process from source to sink being dominated by drainage systems. The source-to-sink pattern with structural features has complicated the distribution of the Mesozoic strata. Since all information is recorded in the associated basin infill, we conducted research on new samples from the Jurassic, Cretaceous, Permian that can provide limitations for the missing Triassic stratum. By analyzing the difference between the depositional age and the crystallization age of zircon grains, we confirmed the Jurassic extensional tectonic setting and the collisional tectonic setting of the Triassic and Cretaceous. By comparing the new detrital zircon geochronological data with the published data, a morphological classification of zircons applicable to complex transport processes was proposed, and the characteristics of provenance indicated by this classification were combined with new sedimentary and seismic stratigraphic evidence to establish two source-to-sink patterns, namely dominated by drainage basin under the Jurassic extensional setting and dominated by drainage channels under the Cretaceous collision setting. Under the Jurassic extensional setting, the debris mainly originated from the Tiekelike Uplift, and the subsidence of the hanging wall resulted in an increase in the accommodation space. The sedimentary system was small, and the distribution direction of isolated sedimentary centers in the sedimentary basin is parallel to the fault, which indicated that drainage basin which perpendicular to the direction of the provenance dominating, reducing the catchment area. Under the Cretaceous collision setting, the transportation of debris from the West Kunlun Orogenic Belt and the Tiekelike Uplift to the basin means that the catchment area increases and the role of drainage basin weakens. The overlapping sedimentary systems and changes in sedimentary facies indicate an increase in number and scale of drainage channels.