Research on Wen'an slope fracture features of Baxian sag

According to the Wen'an slope analysis ofBaxian sag, the main faults are syngenetic normal faults, epigenetic normal faults and strike-slip faults, in which mainly are syngentic faults. According to the combination of fracture characteristics, the study area was divided into fivefaults: Changfeng Town-Wen'an graben and horst faults,Zhaogezhuang-Zuogezhuang graben and horst faults,Shigezhuang-Suqiao graben and horst faultsw, Taishanstrike-slip fault zone, Xinan Town graben and horst faults.Dated from the late Mesozoic, fault development followed byweak-strong-weak variation rule, in Kongdian forma- tion-Sha Ⅱ deposition period, developed with the strongest faults, then in Sha Ⅰ-Dongying deposition. The Neogene, late Mesozoic and the Quaternary developed with the weakest fault activity; Late Mesozoic to Paleogene developed slopemain faults, which has played a controlling role in Wen'anslope Paleogene tectonic evolution, the epigenetic faults developed from neogene has played a complicated role to pretectonic. Variation rule shows strong-strong-weak-weakin the study area along the structure toward the plane fromthe Southwest to the Northeast. In the graben and horstfaults, faulting activity is the strongest in the intersection ofthe graben and the horst, and Tanshan strike-slip faultingzone.