松辽断陷盆地群沉积演化及层序地层学模式

Sedimentary Evolution and Sequence Stratigraphic Models of Faulted Basin Group in Songliao Basin

松辽断陷盆地群地层,即深层,主要为一套砾岩、砂砾岩、砂岩、粉砂岩、泥岩夹火山岩、煤层组成,从下到上,一般划分为火石岭组、沙河子组、营城组、登娄库组。从层序地层学观点,从下到上划分为3个超层序、11个三级层序(SQ1～SQ11)。发育的沉积相类型有冲积扇相、河流相、湖漫相、湖泊相、扇三角洲相、三角洲相、湖底扇相和火山岩相。从沉积特征可划分为4个演化阶段,即扇三角洲—湖泊—火山岩充填期、扇三角洲—湖泊—河流三角洲充填期、河流三角洲—湖泊—扇三角洲充填期和河流三角洲—湖泊充填期,从而将本区断陷沉积层序归纳为3种层序地层学模式,即断陷型、断坳并存型、坳陷型层序地层学模式。

The strata of Songliao fault basin group include Huoshiling, Shahezi, Yingcheng and Denglouku Formations. From the viewpoints of sequence stratigraphy, this set of strata can be dividing into 3 super-sequences and 11 third-order sequences. The sedimentary facies developed mainly include alluvial fan, fluvial, lake flat, lacustrine, fan delta, delta, lake-floor fan and volcanic rocks. There developed four depositional filling-up stages, i.e., fan delta-lacustrine-volcanic rocks, fan delta-lacustrine-delta, delta-lacustrine-fan delta and delta-lacustrine The authors, therefore, concluded three types of sequence stratigraphic models including fault basin, faultdepression basin and depression basin.