Sequence Stratigraphy Of Cambrian-Ordovician In Awati Depression, Tarim Basin

The detailed sequence stratigraphic research about Cambrian-Ordovician in Awati depression has been done on the basis of the outcrop sections and the well logs. After the classification and recognition of different order of sequences of the Cambrian-Ordovician, the sequence stratigraphic system has been established, which is composed of different orders of sequences including 39 third-order sequences, 13 supersequences, 4 supersequence sets and 2 megasequences.Based on the analysis of the characteristics of third-order sequences, 7 kinds of sequence architectures which are developed in different depositional settings have been summarized, and the generating process and controlling factors for every architecture style have been discussed. It can be concluded that the sequences developed in shelf setting have symmetric structure with TST and HST or LST, TST and HST, while those in shallow carbonate platform environment are characterized with highstand system tract (HST) stacked by HST. Through the sequence stratigraphic correlation of Cambrian-Ordovician, the favorable intervals of source beds and reservoir layers in sequence stratigraphic framework have been evaluated, and their distributions of facies tracts have been discussed.