渤海湾盆地黄河口凹陷古近系沙一段混积岩发育特征及沉积模式

为了厘清渤海湾盆地黄河口凹陷古近系沙一段湖相混积岩优质储层的空间分布规律，通过岩心观察、薄片鉴定、阴极发光、碳氧同位素及微量元素等分析测试，分析混积岩发育特征和控制因素，总结其沉积模式.结果表明，研究区主要发育碳酸盐岩与碎屑岩组成的混合沉积和混积层系.混积岩具有旋回性变化的特点，垂向上自下而上由A段-颗粒云岩质砂砾岩、B段-颗粒云岩质砂岩、C段-颗粒云（灰）岩、D段-泥云（灰）岩和E段-泥页岩构成，其中C段物性相对较好，为有利储层发育段；平面上随着离物源区距离的增大，由以陆源碎屑混积岩为主，过渡到以碳酸盐岩混积岩为主.研究区混积岩发育受古构造、古地貌、古气候、陆源碎屑供给、湖平面等多种因素的联合控制，并以陆源碎屑供给和古气候最为重要，在此基础上建立了混积岩发育模式. 

Sedimentary Characteristics and Model of Mixed Siliciclastic-Carbonates of Member 1 of Paleogene Shahejie Formation,Huanghekou Sag,Bohai Bay Basin

Based on the core observation,thin section identification,cathodoluminescence,oxygen-carbon isotope,and trace elements analysis,sedimemtary characteristics,controlling factors and model of mixed siliciclastic-carbonates are analyzed for finding out the spatial distribution of high-quality reservoir in the Member 1 of Paleogene Shahejie Formation in Huanghekou sag,Bohai Bay basin. The results show that it is mainly composed of carbonate and clastic rock mixed deposition and mixed layer system in the the study area. Mixed siliciclastic-carbonates of study area show cyclic change,developing section A-granular dolomitic glutenite,section B-granular dolomitic sandstone,section C-granular dolomitic (gray) rock,section D-mud dolomitic (gray) rock,and section E-shale from bottom to top. Section C is the potential reservoir with good porosity. On the plane,with the increase of the distance from the provenance area,it shows the transition from mainly mixed siliciclastic-carbonates clastic migmatite to carbonate mixed siliciclastic-carbonates. Sedimentary model of mixed siliciclastic-carbonates in the study area is built based on the analysis of controlling factors (e.g.,paleostructure,paleogeomorphology,climate,and lake level change),and it is found that the terrigenous clastic supply and climate are the main factors.