Mixed Sedimentary Characteristics And Models Of The Cross-Pu Formation In Dejiang Area,Guizhou Province

Based on the observation and measurement of outcrops of the ordovician xishuobu formation in dejiang region,guizhou province,the mixed sedimentary characteristics of terrigenous clasts and carbonate components in the xishuobu formation were systematically studied.According to the research classification of sandstone samples collected,it is concluded that the field measured profile is mainly composed of mudstone,silty mudstone,calcareous sandstone and sandy limestone at the bottom vertically.In the middle,there are argillaceous limestone,argillaceous siltstone,siltstone and silty mudstone.The upper part is mainly argillaceous limestone mixed with mud and silty mud.According to the grain size analysis parameters of sandstone,it has obvious characteristics of coastal sand and continental shelf sand.Limestone in the longitudinal distribution change is more obvious,from the carbon and oxygen isotopes in the carbonate rock data show that at that time in the shallow sea environment.Affected by changes in sea-level change,tectonic movement,climate and other factors,the formation of terrigenous clastic and carbonate composition of mixed sedimentary characteristics,the formation of peperite and terrigenous clastic rocks,carbonate rocks and peperite formed in the interlayer mixing product mix product formation,sedimentary type with the gradient type mix deposition and mutation type mixed deposits.Based on the understanding of predecessors and the results of field and laboratory studies,the mixed sediment model of continental shelf facies was further established to provide examples and references for future studies.