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通过岩心观察、薄片鉴定、X-射线衍射、有机碳分析等技术,综合矿物成分、有机质含量、沉积构造等因素,对雅布赖盆地小湖次凹新河组下段半深湖—深湖细粒沉积岩岩相进行研究,形成了细粒沉积岩四组分三端元的岩相划分方案。结果表明:新河组下段半深湖—深湖细粒沉积岩发育9种岩相类型,其中以贫有机质块状黏土质细粒长英沉积岩、贫有机质纹层状硅质碎屑型混合细粒沉积岩、贫有机质块状长英质黏土岩、中有机质纹层状硅质碎屑型混合细粒沉积岩、中有机质纹层状长英质黏土岩、富有机质纹层状碳酸盐型混合细粒沉积岩等6种岩相为主。岩相类型与特征反映沉积环境和沉积机理的差异,在前三角洲—半深湖的环境中,波浪增强型沉积物重力流普遍发育,形成纵向上贫有机质块状黏土质细粒长英沉积岩—纹层状硅质碎屑型混合细粒沉积岩—块状长英质黏土岩的叠置,反映水动力渐弱的过程;在半深湖—深湖环境中,水体相对安静,悬浮沉积为主,陆源碎屑输入少,碳酸盐和黏土较发育,形成中—富有机质纹层状混合细粒沉积岩和黏土岩。
By means of core observation, thin slice identification, X-ray diffraction and organic carbon analysis and other factors, taking the factors of mineral composition, organic matter content and sedimentary structure into consideration, The grain-sedimentary lithofacies have been studied to form the lithofacies division scheme of four-component three-terminal element of fine-grained sedimentary rocks. The results show that there are 9 kinds of lithofacies in the semi-deep lake and deep lake fine sedimentary rocks in the lower part of the Xinhe Formation, of which, the lean organic-like massive clay-bearing fine quartzitic sedimentary rocks and the lean organic-textured layered siliciclastic mixed fine grains Sedimentary rocks, lean organic massive loften quartz clay, medium organic laminar siliceous fusiform mixed fine-grained sedimentary rocks, medium organic laminar long quartzitic clay rock, and organic textured laminar carbonate-type mixed fine grain Sedimentary rocks and other six kinds of rock-based. The types and characteristics of lithofacies reflect the difference between depositional environment and depositional mechanism. In the former Delta-semi-deep lacustrine environment, the gravity-flow of wavy enhanced sediments generally develop, and the formation of longitudinally poor organic massive lump clay-bearing granite- The superposition of laminar siliceous microfacies sedimentary rocks and massive quartzitic clayey rocks reflects the hydrodynamic fading process. In semi-deep lakes and deep lakes, the water bodies are relatively quiet and the sediments are mainly suspended Less terrigenous input, more developed carbonate and clay, forming medium-rich organic matter layered mixed fine sedimentary rocks and clay rocks.