松辽盆地拗陷期坡折带特征

Characteristics of slope break in depression stage of Songliao Basin

论述了松辽盆地拗陷期坡折带即挠曲坡折带的特征以及挠曲坡折带对高频层序结构、沉积相带分布、砂岩类型和岩性油气藏类型分布的控制作用,总结了确定挠曲坡折带的方法。挠曲坡折带形成于盆地演化的拗陷发育阶段,由地壳运动的差异沉降和不均衡调整控制形成。挠曲坡折带与地壳深部莫霍面陡变带、地温梯度变化带和深大断裂带有良好的对应关系,并受控于盆地断陷阶段断裂坡折带的发育和分布。

The characteristics of flexure slope break and the controlling effects of flexure slope break on the structures of high-resolution sequence strata, distribution of depositional facies belt and the distribution styles of sandstone and lithology reservoir were discussed. A set of methods for defining flexure slope break were proposed. The flexure slope break was generated in depression stage of basin evolution and formed by the differential subsidence and non-equilibrium regulation of earth motion. The flexure slope break had the excellent corresponding relationship with the abrupt change belts of Moho-discontinuity and geothermal gradient and was controlled by fracture slope break in rift subsidence stage.