松辽盆地北部徐家围子断陷沉积体系及其演化规律

Depositional system and its evolution of Xujiaweizi fault basin

利用大量岩心、录井、测井及地震资料 ,运用沉积学和层序地层学最新方法、理论 ,研究了松辽盆地徐家围子断陷沉积体系类型、特征及沉积体系的时空演化规律 .结果表明 ,徐家围子断陷发育的沉积体系有冲积扇河流体系类、扇三角洲体系类、辫状河三角洲体系及湖泊体系 .火山岩相在断陷演化的早、晚期较为发育 .冲积扇河流体系、扇三角洲沿盆缘断裂呈裙带状发育 ,向盆地方向相变为深湖相 ,在扇三角洲的深湖区发育有湖底扇 .

Based on a great deal data of core, logging and seism, and with the newest methods of sedimentology and sequence stratigrphy, this paper deals with the types, characteristics and space-time distribution of depositional systems of Xujiaweizi Fault Basin. There are fluvial depositional system, fan delta depositional system, braided stream delta depositional system and lacustrine system developed in the fault basin, and vocanic facies also well developed in the basin during early and late stage of the basin evolution. Fluvial depositional system, fan delta depositional system were developed along the margin fault, toward the basin, change to deep lake facies, and in the deep lake area near the fan delta, lake floor fan probably developed, braided stream and braided stream delta depositional system mainly developed in the flexible marbin of the fault basin.