关键词: 多样性, “往返式”走滑运动, 郯庐断裂, 济阳拗陷, 埕岛地区

Abstract: In this study, we analyzed the formation mechanism of Paleozoic tectonic and stratigraphic diversity in Chengdao Area using 3D seismic, drilling data, and regional stress field results. The results show that affected by the left-lateral →rightlateral "reciprocating" strike-slip movement of Tanlu fault during the Late Triassic-Eocene period, Paleozoic in Chengdao Area experienced three stages including "compressing and plunging folds, stretching and reversing into mountains, and differential slipping and shaping". At the end of the Triassic period, the NE-SW region in Chengdao Area was compressed from SW to NE under the left-lateral strike-slip movement of Tanlu fault. This compression movement resulted in the formation of three overthrust blocks in the west, middle, and east. The difference effect in the uplift caused different degrees of erosion in Paleozoic. During the late Jurassic-early Cretaceous period, Chengdao Area experienced stretching from the NWW-SEE to the NW-SE direction under the left-lateral strike-slip movement of Tanlu fault. Unbalanced reversion of thrust faults forms three rows of mountains in the west, middle, and east, as well as the "convergence in the south and discrete in the north" fault. In the Late Cretaceous-Eocene, the base shearing displacement of the three rows of the mountains from the west to the east direction in Chengdao Area is increasing under the effect of right-lateral strike-slip movement of Tanlu fault. The EW fault and the NEtrending strike-slip fault formed due to the base shearing from the middle mountain and east mountain, respectively, which tend to cut into each other. The structural styles and lithology distributions are now more complex.

Key words: diversity, reciprocating strike-slip movement, Tanlu fault, Jiyang Depression, Chengdao Area