The Research Of Dolomite Sedimentary Microfacies In Dengying Formation Of Sinian,Songlin Area,Zunyi City,Guizhou Province

The Sinian Dengying Formation because of deep buried depth,older age,longer time evolution,high-quality reservoir exploration and exploitation,it is difficult to predict.Has always been the focus of oil and gas exploration and development.In this paper,the field characteristics of Zunyi pine,Jinsha Yankong and Renhuai Bay in three profiles of detailed research,and combined with the analysis of thin section combined with the basic theory of tectonics,sedimentology and many other disciplines,microfacies has done deep research on deposition of Zunyi pine forest area Sinian Dengying Formation,sedimentary phase.Through the research,this paper obtains the following understanding:(1)the three major sections of the study area,a section of Zunyi pine forest light and underlying the Doushantuo Formation black shale Baiyun unconformable contact,contact light section and two black shale in Niutitang Formation unconformity,three section,four section of light bulbs are denudation;Jinsha Yankong strata the exposed relatively complete,including a lamp with the underlying Doushantuo black dolomitic shale unconformable contact,two lamps and overlying three lamp unconformable contact;Renhuai Bay section exposed a part of the lamp and lamp two strata,including a lamp with the underlying Doushantuo black dolomitic shale as unconformity contact light above two being eroded.(2)the study area of Dengying dolomite three structure types: including crystal structure,particle structure and microbial structure.The structure of the crystal is composed of the crystal structure and the crystal structure.The main structure of the particle is the inner clastic structure.(3)there are mainly three types of rocks in this area: grain,dolomite,and rock.The grain dolomite mainly consists of the crystalline dolomite and the microcrystalline dolomite,and the granular dolomite is mainly composed of the inner clastic dolomite.(4)the area of dolomite platform facies and depositional period of the upper Yangtze platform because of light,warm and dry climate,water is shallow,the main tidal flat facies at the junction surface,a light at the end,with the gradual development of open sea water depth,and intraplatform microfacies,the sedimentary period of two a light,seawater deepened because of the upper Yangtze platform warm climate,clear water,algae bloom and extensive development of mud mound in platform margin,including core,radical and reef,three sedimentary microfacies.