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鄂尔多斯盆地是我国最重要的含煤及含油气盆地之一。中生代盆地充填序列可按古构造运动面划分为五个构造层序（ＴＳ－１～ＴＳ－５），分别与盆地构造演化的阶段性相当。受秦岭带中三叠世末期造山运动的影响，盆地西南缘形成了晚三叠世的前渊，不整合于其上的保罗系属于继承性盆地充填，延安组正属于这一阶段的相对稳定期。已发现其上、下界面均为不连续面，并都发现有深切谷，因此延安组恰好是一个三级层序。其内部可进一步划分８～１１个四级层序。延安期层序内部体系域的演化有三分性，但不宜套用源于海相地层的体系域命名。本文就此问题进行了探讨和命名。鄂尔多斯盆地层序地层研究的成果已被有效地用于富煤单元预测、油气储层分析，并在古大陆暴露面优质高岭土矿床的发现和追索中起了重要作用。
The Ordos Basin is one of the most important coal-bearing and petroliferous basins in China. The Mesozoic basin filling sequence can be divided into five tectonic sequences (TS-1 ~ TS-5) according to palaeo-tectonic moving surface, which are similar to the stages of tectonic evolution of the basin, respectively. Due to the influence of the late Triassic orogeny in the Qinling Belt, the Late Triassic foredeep formed in the southwestern margin of the basin, and the unconformity of the Paulian system belonged to the succession basin filling. The Yan’an Formation was relatively stable at this stage period. It has been found that the upper and lower interfaces are discontinuous, and are found in deep valleys, Yan’an Formation is just a three-level sequence. Its internal can be further divided into 8 to 11 four-level sequence. The evolution of the internal system tract in the sequence of Yan’an period is threefold, but it is not appropriate to apply the domain name derived from the marine strata. This article explores and names this issue. The results of sequence stratigraphy research in the Ordos Basin have been effectively used for the prediction of coal-rich units and for the analysis of oil and gas reservoirs, and have played an important role in the discovery and reclamation of high-quality kaolinite deposits on the ancient continental exposed face.