通过岩性、测井和地震资料分析,结合区域沉积环境和构造背景,探讨辽东湾地区走滑-伸展断陷时期辽西凹陷南洼不同构造单元的沉积充填模式.辽西凹陷南洼古近系东营组第二段分为上下2个亚段,其中东二下亚段沉积时期,裂陷作用减弱,西部物源进入湖盆,近源斜坡带发育以辫状河三角洲为主体的沉积体系,洼陷带和凸起带以湖泊沉积为主;东二上亚段沉积时期,西部沉积物继续充填直至满盆后越过辽西低凸起向东溢出,整个研究区发育大面积辫状河三角洲,其沉积特征及差异主要受构造-古地貌及沉积物供给共同控制.依据沉积相平面展布及连井剖面对比,建立了辽东湾地区盆满溢砂的沉积充填模式.该模式证实远源砂体并不都是来源于长轴方向的曲流河三角洲,也有可能来源于近源辫状河三角洲沉积;各时期物源体系和构造体系在时间和空间上的有效配置合理控制了砂体的聚集方式和富集程度.%The sedimentary filling model for different tectonic units in Liaodongwan area of south Liaoxi sag during the strike-slip and extension stage is discussed on the basis of analysis of lithology, logging and seismic data,combined with analysis of regional sedimentary environment and tectonic background.The Member 2 of the Paleogene Dongying Formation (E3 d 2 )in Liaodongwan area can be divided into two submembers.During the sedimentation of the lower submember Ed 1 ,the rifting became weak and provenance entered the lake basin,forming braided river delta in gentle slope and forming lake facies in sag belt and salient belt.During the sedimentary period of upper submember Ed 2 ,the sediments from the west continued to fill the basin until it overflowed to the east.Braided river delta facies well developed in the study area,and its sedimentary characteristics and differences are controlled by the combination of tectonics,palaeogeomorphology and sediment supply.On the basis of sedimentary facies and connective well section,the sand depositional filling pattern of Liaodong Bay basin is established.This sedimentary filling model effectively solved the difference between the size and scale of the sand bodies and the source of sand bodies in south of Liaoxi sag.It is considered that the effective allocation of the provenance and structural system in time and space in different periods controlled the aggregation and enrichment degree of the sand bodies.
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