The Sequence Stratigraphics Characteristics of Upper Permian in the Northeastern Sichuan Basin

On the basis of stratigraphic theory and the analysis of sedimentary facies,lithology and lithofacies and the changing of accommodation of field profile,sequence stratigraphy are researched to the upper Permian at Yanggudong profile in Dukou town,Xuanhan County,Northeastern of Sichuan Basin.Three types and six stratigraphic sequences boundary are discriminated.One 2-order sequence and five 3-order sequences in upper Permian,three 3-order sequences in Wujiaping Formation and two 3-order sequences in Changxing Formation are discriminated.We have constructed the sequence stratigraphic framework of upper Permian on the basis of sequence dividing.By the correlation of the change of accommodation curve and outcrop sequence stratigraphic dividing,there is a very well corresponding relation between the two curves.The relation not only verifies the correct of classification of the sequence stratigraphy but also shows the practicality and objectivity of cycle analysis technique of Fischer plot.