Eastern and central Asia is characterized by complex intraplate deformation that is not related simply to synchronous tectonic plate boundaries. This deformation is accompanied by the coupled evolution of large, long-lived, nonmarine intracontinental basins, which are not adequately described by existing basin models. The processes that link intraplate deformation and concomitant basin formation, and feedback mechanisms between sedimentation and structural evolution can be understood better through detailed analysis of distribution, style and timing of deformation, subsidence and sedimentation. The Mesozoic Ordos basin and Cenozoic Qaidam basin are excellent examples of such systems because both are large geologic provinces characterized by thick, relatively continuous packages of syntectonic sediment that accumulated during deformation on the margins of, and within, each basin. Thus, these basins provide the opportunity to document how loci of deformation and sedimentation correlate through time, and how they may exert influences on each other.
The sedimentary and structural history of the Mesozoic Ordos and Cenozoic Qaidam basin is being documented with a combination of geologic maps, measured stratigraphic sections, and other basin characterization such as paleocurrent and provenance analysis, and subsidence modeling. In the Ordos basin, efforts are focused on Mesozoic basin-margin outcrops in the northern half of the basin. In Qaidam, studies include a combination of outcrop geology along the northeast and southwest basin margins, and analysis of seismic reflection data in the basin interior. In these areas, comparison between location and kinematics of specific structures and the geometry and provenance of subsiding depocenters allows the mechanisms that control accommodation space and sediment supply to be determined. It also provides clues to the ways that accumulation of thick sedimentary sequences and associated changes in heat flow, crustal thickness, and lateral distribution of mass affect mechanisms of intrabasinal deformation. This research is attempting to provide a clearer understanding of the secular and spatial relationships between intraplate strain and sedimentation in Chinese basins. This will clarify the structural controls on how such basins evolve and test whether the dynamic changes in sedimentary distribution affect the style or location of structure.
In addition to added insights gained into the history of intraplate deformation in China and improved models for "Chinese-type" successor basins, this project is a platform for undergraduate research overseas and increased collaboration with Chinese co-workers. Analog sedimentary systems in the western United States provide comparative examples to the basins studies in China, and can be used as natural classrooms to train undergraduate researchers and translate the lessons of this research project to the public.
