松辽盆地北部葡萄花油层事件沉积

在松辽盆地北部长垣以西葡萄花油层下部发现了风暴岩和浊积岩事件沉积,两者均属于较深水低密度沉积。根据岩性、岩相和沉积构造特征,风暴岩从下向上可依次划分为液化泥岩、含砾泥岩、泥砾岩、密集砾岩、湖相泥岩、滑塌变形6个岩相段;与之对应的形成过程依次为:液化、混杂悬浮、冲刷、牵引、稳定、滑塌变形6个阶段。浊积岩由6期事件形成,下部为不完整的鲍玛序列,分别由A、B2段构成;最后一期相对较完整分别由A、B、C、E段构成。风暴岩及浊积岩均形成于坡折带发育区的低水位体系域,两者具备相似的成因背景,其形成过程具内在的因果关系,松辽盆地长垣以西地区深水低密度部分浊积岩是由风暴作用机制触发而形成的。

Accident sedimentary of Putaohua Formation in the north of Songliao Basin

The deep-water low-density Tempestite and Turbidite sediments were found in Putaohua Formation in the north of Songliao Basin. According to lithology facies and sedimentary structure, the tempestite was divided into six sections from bottom to top, ineluding liquefied mudstone section, mudstone with conglomerate section, mudstone conglomerate section, compact conglomerate section, lacustrine mudstone section and turbidity section. The responding generation of the tempestite includes six steps of liquefied, chaos floating, flow erosion, pull flow, equability and slump. The turbidite was resulted from six cycles, and each of them includes A and B members of imperfect Boma succession. The final cycle includes four members of A, B, C and E. The tempestite and turbidite were formed in the lowerstand system tract of slope break region. They have similar genetic background and inherent relationship. The turbidite with lower density generated in deep water was resulted from storm action.