Research On The Hot Water Deposition And Diagenesis Of Easter Shandong Offshore Ri-Qing-Wei Basin

The Ri-qing-wei Basin in eastern Shandong is located in the middle part of the Su Lu orogenic belt,between the Jiaolai Basin and the South Yellow Sea basin,which is formed in the Cretaceous rift basin.The Triassic metamorphic rocks of the Su Lu orogenic belt are based on the development of distant turbidite,hot water sedimentary siliceous rocks and siliceous sandstones transformed by hot water.Through a field investigation exposed better Laoshan passes,Castle Peak,peach,etc.section of Zhou Ge Zhuang Ri-qingwei,depicting four profiles of stratum,lithology,summarize of hydrothermal sedimentary rocks,Qingdao Weihai basin geochemical characteristics of diagenetic hydrothermal sedimentary rocks.Summed up the sedimentary model of hydrothermal sedimentary basin on Ri-qing-wei Basin.The main part of the Ri-qing-wei Basin is mainly Laiyang group.The common dark siliceous rocks--greenish gray sandstone and gray sandstone sequence are siliceous rocks,which are mostly laminated or with thin interbedded layers of gray siltstone.The magmatic rocks of the Laiyang group,deposited at the bottom of the Qingshan group,are unconformable in angle.In the sedimentary strata of the Laiyang group,the basic and middle basic magmatic intrusions are visible.In this paper,53 typical rock samples are selected from four sections to study the hot water deposition.The origin of the hydrothermal sedimentary rocks,the sedimentary environment and the relationship with the volcanism are summed up by the main elements,trace elements and rare earth elements respectively.Through the analysis of geochemical data,form Ri-qing-wei Basin,not only has also been the hot water,the input of terrigenous material,the sedimentary environment also showed the continental margin deposits,only Zhou Gezhuang profile shows continental sedimentary environment,tectonic background combined with the study area,transition area analysis of sedimentary environment of hydrothermal sedimentary rocks of the continental margin to ocean basin rift basin.Through the observation of the thin section of rock samples,combined with scanning electron microscopy and XRD technology,we conclude that the Cheng Yan action in the Japan river basin is mainly composed of compaction,cementation,metasomatism and dissolution.Compaction of the mainshow is linear convex quartz particles contact,mica squeezed into strips and strip alignment;cementation for siliceous cementation,as quartz overgrowth and a cryptocrystalline chalcedony cementation,siliceous cementation,also can see the main clay minerals,such as chlorite,and metasomatic pyrite;it can be seen that the effect of calcite metasomatism of quartz and feldspar;dissolution is dissolution of quartz,feldspar dissolution porosity erosion phenomenon in rock specimen.Based on the above analysis,a hydrothermal sedimentary model of the Ri-qing-wei Basin is proposed,namely,the episodic hydrothermal terrigenous clastic mixed deposition model,which is divided into two stages.The first stage is the mixed deposition stage of hot water and terrigenous clastic,and the second stage is the stage of brine compaction.The two stages can be carried out alternately.