松辽盆地东岭地区早白垩世小型断陷的充填特征与演化过程

Filling Characteristics and Evolution Analysis of the Early Cretaceous Small Fault Depression in Dongling Region, Songliao Basin

通过岩芯观察资料、测井资料及地震资料分析,对松辽盆地南部火石岭组地层沉积相的类型和特征进行了研究。综合分析表明:火石岭组上覆火二段为全区广泛发育的火山岩,其下的火一段沉积岩可划分为5个四级层序;其沉积环境主要为扇三角洲和湖泊沉积,断裂转换带显著地控制了沉积相带的空间分布。火石岭组一段沉积演化主要受控于小型断陷内可容纳空间及沉积物供应的变化,可划分为两个阶段:早期属于低位水进体系域,以滨浅湖至半深湖相沉积为主,为湖扩阶段;后期高位体系域以扇三角洲相充填为主,为湖退阶段。

Based on the core observation, drilling and seismic data, the sedimentary characteristics and the distribution of sedimentary facies and sedimentary evolution of Huoshiling sequence were studied. The results show that the overlying volcanic rocks widely developed in nearly whole region are member 2 of Huoshiling formation, and member 1 of Huoshiling formation can be divided into five level 4 sequences. Delta facies and lake facies are the mainly sedimentary facies in Huoshiling formation. Due to the small fault＇s accommodation space and sediment supply change, the sedimentary evolution in member 1 of Huoshiling formation is divided into two stages： the early LST period of Huoshiling formation is dominated by littoral and shallow lake-half deep lacustrine deposition, and the late HST period of Huoshiling formation is dominated by fan delta deposition. The LST is transgression period, and the HST is retrogression period.