Permian Stratigraphic Sequence And Basin Properties In The Jurihe Region Of Inner Mongolia

The study area is located in the northern-central part of the Inner Mongolia Autonomous Region,in the Junrihe region of Sunit Right Banner.The Bauhantu Island arc zone and the Wendur Temple suture zone have a complex geological background.In this paper,the study area is characterized by cross-sectional dating,zircon U-Pb isotope dating,geochemistry,and source analysis of clastic components.The Permian system undergoes stratigraphic delineation,analysis of eruptive or sedimentary environments and phase patterns,and tectonic background analysis to characterize the Permian basin in the region.The paper also discusses the sedimentary environment and material sources.The paper reorganizes and clarifies the Permian stratigraphic sequence and its age in the Jurrihe area,and analyzes its sedimentary environment and material sources.Among them,the Early Permian Three-Faced Well Group developed alluvial fan,coastal shallow marine phase and turbid accumulation fan phase sedimentation;the Early Permian Late Eritu Group is a laminar layer,and the Early Permian Three-Faced Well Group is a laminar layer.Volcanic eruption phase accumulation,andesite zircon U-Pb age is 279.2 ± 1.2 Ma;Middle Permian Yujia Beigou Group is fan The youngest age of the clastic zircon U-Pb was 274.49 ± 2.86 Ma,deposited from the Delta and isolated terrace phases.The analysis of zircon age source and clastic component reflects that the source of the Sanfanjing Group and Yujiabeiigou Group is from North China Kraton.The paper summarizes the volcanic rocks accumulation sequence and petrographic characteristics of the Eritu Group,and concludes that the andesites of the Eritu Group are a set of calcareous and alkaline rocks.The volcanic rocks are of high potassium-calcium alkaline series and are inferred to be bimodal volcanic rocks,produced in a post-collisional extensional environment.Combined,the Permian phase of the study area is inferred to be a rift valley basin,with the entire sedimentary process occurring in an extensional tectonic setting.The sedimentary environment is volatile to progressively stable,and the sedimentary basin has undergone a progression from intra-land rift to passive continental margin to inter-land rift(limited Ocean Basin)stages of evolution.