鄂尔多斯盆地石千峰组高分辨率层序地层学特征

针对鄂尔多斯盆地石千峰期陆相沉积,以高分辨率层序地层学理论为指导,以基准面旋回层序级次的划分为依据,将石千峰组划分为1个超长期、5个长期、14个中期和若干个短期基准面旋回层序,且存在向上"变深"非对称型(A型)、向上变浅非对称型(B型)和对称型(C型)等形式的中短期基准面旋回层序结构;详细分析了各级次旋回层序的结构类型、沉积序列和叠加样式;建立了以长期旋回层序界面和最大洪泛面为等时地层格架、以中期旋回层序为等时地层单元的层序地层格架.

High resolution sequence stratigraphy characteristics of Shiqianfeng Formation in Ordos Basin

According to the continental deposit of Shiqianfeng Formation in Ordos Basin,guided by the theory of high-resolution sequence stratigraphy,and based on the classification of base level cycle sequence,this study has divided Shiqianfeng Formation into one super-long period,five long periods,fourteen middle periods and several short periods base level cyclic sequences. There exist three types of middle-short periods base level cyclic sequence structures,asymmetrical up-deepening type(mode A),asymmetrical up-shallowing type(mode B) and symmetrical type(mode C).It also analyzes the structural type, sedimentary sequence and superposition pattern of different cyclic sequences in detail and builds up an isochronous stratigraphic framework of long period cyclic sequence interface and maximum inundation interface.It also establishes a sequence stratigraphic framework taking middle period cyclic sequence as isochronous section of reservoir.