Genesis Of Cambrian Dolomite In The De Jiang Area,Guizhou Province

The cause of dolomite has always been a long-standing topic in the field of sedimentology.Research on the properties of dolomite fluids and diagenesis has been a hot topic in recent years.To clarify the genesis of dolomite,it is especially important for understanding the oil and gas exploration work with dolomite and its related carbonate rocks as reservoirs.When the predecessors conducted research in the Dejiang area of Guizhou,they believed that the dolomite was relatively good in integrity and belonged to the product under the burial diagenetic environment.Based on the previous studies,this paper takes the Cambrian dolomite in the Dejiang area of Guizhou as the research object,and uses the methods of isotope analysis and trace element analysis through the study of stratigraphic characteristics,tectonic features,sedimentary facies characteristics and petrological characteristics.The rock types,sedimentary facies,diagenesis and diagenetic environment of the Cambrian dolomite are discussed.Take the following results and understanding:Through the observation of the field and the analysis of the flakes,the structure-genetic classification scheme was adopted,and the Cambrian dolomite was classified in detail,and the microcrystalline dolomite,the powdered crystal dolomite,the medium-coarse crystalline dolomite were identified.Micro-bright sand gravel dolomite,bright crystal residual sand dolomite,powder dolomite.The structure of the rock is mainly microcrystalline structure,medium-coarse crystal structure,fog core bright edge structure,residual sand grain structure and mud crystallite structure.The sedimentary structures mainly include laminated structure,horizontal bedding,tapered bedding,pane structure,and tent structure.According to the rock type,sedimentary structure and sedimentary rock combination,the Cambrian sedimentary facies in the study area are divided into tidal flat.The geochemical method is used to analyze the diagenetic environment of dolomite in the study area.The genetic mechanism of dolomite is dolomite osmosis.The diagenetic fluids of dolomite are mainly seawater fluids related to seawater or seawater,and the values of?¹³C and?¹⁸O are generally negative.The comprehensive petrological characteristics and geochemical characteristics of the diagenetic environment suggest that the dolomites in the Dejiang area of Guizhou have good prospects for exploration.