根据陆相地层层序发育的特点,冲积扇、河流、三角洲或湖泊沉积环境,均受地层基准面控制,地层基准面穿越旋回控制着陆相环境重大层序分布。根据不同时间间隔的基准面穿越旋回序次,可将陆相层序划分为盆地充填层序、构造层序、层序、亚层序及小层序5个级别。每个层序(三级)根据基准面的波动可划分为基准面上升沉积体系域和基准面下降沉积体系域,然后可进一步根据亚层序组的叠置特征进行细分。 According to the characteristics of terrestrial stratigraphic sequence development, alluvial fan, river, delta or lacustrine sedimentary environment are controlled by the formation datum, and the stratigraphic datum traverses cyclically to control the major sequence distribution of the terrestrial phase. The terrestrial sequence can be divided into five stages: basin fill sequence, tectonic sequence, sequence, sub-sequence and small sequence according to the crossing order of datum planes with different time intervals. Each sequence (level 3) can be divided into a base-level rising sedimentary system and a base-level falling sedimentary system based on the fluctuations of the base level, and then further subdivided according to the superposition features of the sub-sequence group.