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松辽盆地中西部的裂谷作用自下白垩统沙河子组沉积期持续到营城组沉积期,东部从下白垩统沙河子组沉积期持续到登娄库组沉积期.在不同构造层次形成了变形特征有别的构造,中浅层伸展构造的基本要素是断陷盆地边界主断裂,基本结构单元是半地堑和半地垒,横向上呈多米诺型垒-堑构造.主断裂中东倾者倾角缓但向东有增大的趋势;西倾者数量有限但倾角较陡.断陷包括水平拉张量大而裂谷期沉降量小的半地堑和水平拉张量小但裂谷期最大沉降的半地堑.这些断陷盆地在北北东方向呈串珠状,自西而东成带.在中-下地壳发生韧性变形,形成一向东倾拆离带,深度范围15～30km. 裂谷的扩展有3种方式,即边界断裂的斜向后退扩展,断陷带的走向式扩展,断陷群的横向扩展.
The rifting in the central and western Songliao Basin continued from the sedimentary period of Lower Cretaceous Shahezi Formation to the sedimentary period of Yingcheng Formation and from the sedimentary period of Shahezi Formation of Lower Cretaceous to Denglouku Formation in the eastern part of the Cretaceous. The deformation features of other structures, the basic elements of the middle and shallow extensional structure is the main faulted basin boundary faults, the basic structural unit is a half-graben and semi-basement, horizontal was domino-type barrier-grabbing structure. But the number of west-dipping is limited but the dip angle is steep.The faulting includes half-graben with small horizontal pull-off but small amount of horizontal pull-out but small amount of horizontal pull-out but small rift The most subsided half-graben.These faulted basins are beaded in the north-north east direction and are formed from west to east, with ductile deformation in the middle and lower crust, forming a facies eastward detachment zone with a depth of 15-30 km There are three ways for the extension of the rift, that is, the diagonal retrogressive extension of the boundary fault, the strike expansion of the rift belt and the horizontal extension of the rift group.