ANALYSIS ON THE SEDIMENTARY ENVIRONMENT OF THE CARBONIFEROUS CARBONATE AND DETRITAL ROCK ALTERNATING SEDIMENTATION IN THE MAIGAITI SLOPE OF THE TARIM BASIN

By study on the petrology,sedimentary,logging curve and seismic characteristics of the Carboniferous in the Maigaiti Slope of the Tarim Basin,the Carboniferous of the area was divided into eight lithologic members including three carbonate rock ones and five detrital rock ones,that is,the Donghe Sandstone Member(C₈),the Lower Mudstone Member(C₇),the Bioclast Limestone Member(C₆),the Middle Mudstone Member(C₅),the Standard Limestone Member(C₄),the Upper Mudstone Member(C₃),the Sand-Mudstone Member(C₂)and the Xiahaizi Limestone Member(C₁)from bottom to top.By in-situ core observation and indoor thin-section identification as well as stable isotope and trace clement testing,the sedimentary environment of each lithologic member was analysed,and the vertical distribution of sedimentary facies was obtained.Compared with study taking formations as units before,it is more precise and can direct petroleum exploration correctly. In view of the mixed sedimentation genesis of the Carboniferous by carbonate and detrital rocks in the area,this paper made a discussion on it.