中文摘要：

根据野外露头、钻井岩心及测井等资料,以地层过程-响应沉积动力学为理论基础,运用以基准面旋回为参照面的高分辨率层序地层学理论及其技术方法,将鄂尔多斯盆地西北部下石盒子组划分为1个超长期旋回,其中盒8段识别出2个长期旋回、4个中期旋回及若干短期旋回层序。针对研究区主力含气层段之一的盒8段,以中期基准面旋回为周期,较为详细地探讨了其不同类型的充填样式,并进一步分析了该时期河流-三角洲的沉积-层序响应特征,建立了以中期基准面旋回为单元的沉积-层序构成模式。

英文摘要：

Based on the data from field outcrops,well logs and drilling cores co mbined with the theoretical basis of the stratigraphic and sedimentary process-r esponse dynamic principles,one super long-term cycle is identified in the Lower Shihezi Formation in northwest Ordos Basin by applying the theory and technolog y of the high-resolution sequence stratigraphy on base-level cycle.Member 8 of this formation,one of the main gas-bearing members,is divided into two long-te rm,four middle-term and several short-term cyclic sequences.To analyze this me mber in the study area,detailed study is made on its different filling types ba sed on middle-term base-level cycle as one cycle.Then further analysis is condu cted on the response of sedimentation-sequence in fluvial-delta depositional sys tem of the period.Consequently,architecture model of sedimentation-sequence in fluvial-delta facies has been established based on middle-term base-level cycle,to profound understanding the spatial-temporal relationship.