Chepaizi uplift is a triangle structural belt, which located in Zaire Mountain front and retained between the Sikeshu sag in the south and the Shawan sag in the east. Yet the structural origin of this belt as an autochthonous covered structure, piedmont nappe structure or strike-slip structure remains an open question. The deformation feature and mechanism of Chepaizi uplift and Shawan sag transitional zone is still not fully understood. Transition zone is a good area for the study of the structural deformation and evolution. To discuss the geometry and kinematics of the transition zone is of great value to reveal the tectonic deformation mechanism and basin-and-range relationship, and to future guild oil-gas prospecting. Based on high-quality 3D seismic profile covering most of the study region, we do the accurate structure elucidation, structural modeling and reconstruction by employing unconformity identify, fault-related-fold theory and balanced restoration. Our study shows that seven unconformities and seven tectonic sequences consisting of P1j-P1f, P2x-P2w, P3w, T, J, K, E-Q are observed. The base of Jiamuhe Formation and inner of Carboniferous develop detachments. The deep structural wedges are developed across the study region, the number and geometry of these wedges directly affect the geometry overlying anticline and the difference in different segments. The structural wedges form in the Early Permian and the compaction continues to the Late Triassic. The growth strata grows in Late Triassic and shows the folding time of the P-T tectonic sequence. Afterwards the imbricate overthrust structures from the orogenic zone in the northwest superimpose in this transitional zone in the Late Triassic, and the displacement of the nappe is about 8km. The Permian?Triassic strata on the hanging wall of thrust faults has been totally denuded in the southern zone while little Jiamuhe Formation remaining in the northern zone.
Liang Yusheng Wu Songtao Lu Yu Zheng Menglin Liu Deguang Kong Yuhua Wu Haisheng. The structural model in the transitional zone of Chepaizi uplift and Shawan sag[J]. Chinese Journal of Geology, 2018, 53(1): 155-168.