Study On Sinian System's Stratigraphic Characteristics And Sedimentary Evolution In Western Tarim Basin

In order to reveal Sinian System's Stratigraphic characteristics and Sedimentary evolution in Western Tarim Basin.According to the outcrops,achieved mass of data about rock-assemblage characteristics and distribution,combined with the analysis of sample testingt,the results show that the Sinian of Aksu-Wushi area can be divided into Sugaitebulake and Qigebulake formation from bottom to top.The Sugaitebulake can be divided into upper and lower subgroups.The lower subgroups are intertidal clastic deposits,and the upper subgroups main are carbonate-fine clastic sediments.The Qigebulake is dominated by light gray and gray massive,lamellar dolomite,sometimes oblique bedding or interlaced bedding can be find in dolomite.The Sinian of Tiekelike area can be divided into Kuerkake and Kezisuhumu formation from bottom to top.The Kuerkake is mainly composed of thin sandstone and shale interbed,it is also filled with gravel sandstone,feldspar sandstone,it has a layer of dolomite at the bottom.The upper part of the Kezisuhumu is dolomite,Its lower part consists of dark gray,purple,rose sandstone,siltstone uneven interbedded dolomite composition,the bottom is a phosphorus-bearing sandstone section.It can identify the littoral facies,neritic facies,lagoonal facies,restricted platform and other sedimentary facies about Sinian System in Western Tarim Basin.The Aksu area is mainly dominated by shallow water of littoral facies.The Tiekelike area is neritic facies at early age,gradually changed to littoral facies,lagoonal facies and restricted platform at the later stage.