It is dominical by compression and it is small - scale intermountain basin with multi - circles and multi - periods and complex structure . it is 4800km2 area . the exploration of hydrocarbon began in 1950s 以压性为主，是一个经过多旋回，多期次复杂改造性的小型山间瓮地，面积4800平方公里。
Viewed from the ordered stacking patterns of the meter - scale cyclic sequences in the long - period sequences , twenty - six third - order sequences may be identified in the wumishan formation 因此，七级韵律层、米级旋回层和五级准层序组分别与岁差旋回、短偏心率旋回、长偏心率旋回间存在有成因联系。
This variation not only results in the cyclicity of basin evolution , but also the formation of multiple oil - bearing sequence of meso - cenozoic in liaohe basin and adjacent its areas 不同区域应力场的转化不仅导致了盆地演化的旋回性，也为辽河盆地及其邻区中新生代多套含油气层系的形成奠定了物质基础。
This paper shows that favourable oil - pool - forming condition can be found in linnan sag . there are three main kinds of subtle oil - gas - pools : up - acclivity pinch - out sandstone , lenticle and fault - stratigraphy subtle oil - gas pools 沙三下沙三中(旋回c3和旋回c4 )时期是寻找岩性圈闭的最有利层序。
