Three type of sandbox analogue models, including the half graben positive inversion model with uniform basal extension, domino faults positive inversion model with uniform basal extension and symmetrical graben positive inversion model, were prepared to investigate the superposition or alteration of early normal faults by late inversion structures. The results of experiments by one end shortening indicated that during positive inversion period compressional strain was accomplished mainly by new forward propagated thrust faults with lower angle and most of early normal faults were preserved with increasing in dip angle. The possibility that all of early normal faults were inverted to thrust faults was very small. Merely in intensive deformation position, the early normal faults were possible to be completely replaced by thrust faults during positive inversion period. According to the experimental results combining with actual datum from the Qaidam Basin, it was supposed that the Qaidam Basin was a compressional basin during early-middle Jurassic.
Zhou Jianxun,Xu Fengyin,Zhu Zhanjun. STRUCTURAL NATURE OF THE QAIDAM BASIN IN EARLY-MIDDLE JURASSIC INFERRED FROM SANDBOX MODELS OF POSITIVE INVERSION STRUCTURES[J]. Chinese Journal of Geology, 2002, (4): 430-435.