异重流沉积研究进展

发布时间：2018-06-04 14:33

本文选题：异重流 + 异重岩　；参考：《沉积学报》2016年03期

【摘要】：在相关文献调研基础上,综述了异重流沉积研究现状,并结合中生代湖相异重岩研究实例,建立了"沟道—舌状体—朵状体"异重流沉积模式。异重流(hyperpycnal flow)是一种由洪水期河口直接注入、因密度大于汇水盆地水体密度而沿水体底部分层流动的持续型浊流。它呈牛顿流变性质、紊乱流动状态、湍流支撑机制,具有更高的发生频率和稳定的沉积物供给。异重流主要受地形、气候、密度差等因素控制,海洋和湖泊均有发生;水体密度小、近物源、地形高差大、中—小河流发育、构造活动强烈的陆相淡水湖泊更利于异重流的产生,但陆相湖盆异重流沉积并未引起足够的重视。异重流自近端向远端总体呈稀释趋势,依次对应于特定的沉积构造及序列;由异重流形成的沉积岩被称作异重岩(hyperpycnite),以发育由洪水增强—减弱所产生的逆粒序—正粒序组合、层内微侵蚀面、富含陆源有机质区别于其他浊积岩。深入研究异重流沉积,不仅有益于完善重力流沉积理论、分析沉积环境,而且有利于指导深水非常规油气勘探,具有重要的科学价值和现实意义。
[Abstract]:Based on the investigation of relevant literature, the present situation of density current deposition is reviewed, and the dense flow deposition model of "channel, tongue and flower" is established in combination with the case study of Mesozoic lacustrine dissimilar gravity rocks. Hyperpycnal flow is a kind of continuous turbid current which is injected directly by estuaries during flood period and flows along the bottom of the water body because the density is greater than that in the catchment basin. It has Newtonian rheological properties, turbulent flow state, turbulent supporting mechanism, higher frequency of occurrence and stable sediment supply. The density current is mainly controlled by topography, climate, density difference and so on, the ocean and lake have occurred, the water body density is small, the near material source, the topographic height difference is big, the middle-small river is developed, Continental freshwater lakes with strong tectonic activity are more conducive to the generation of density currents, but the density current deposits in continental lake basins are not paid enough attention to. The density flow is diluted from the proximal end to the distal end, corresponding to the specific sedimentary structure and sequence, and the sedimentary rock formed by the density current is called hyperpycnite, which develops the inverse grain sequence and normal sequence assemblage caused by the flood enhancement and weakening. The microerosion surface within the layer is rich in terrestrial organic matter, which is distinguished from other turbidite. It is not only beneficial to improve the theory of gravity flow deposition and analyze the sedimentary environment, but also helpful to guide the exploration of deep water unconventional oil and gas, which has important scientific value and practical significance.
【作者单位】：山东科技大学地球科学与工程学院;
【基金】：国家自然科学基金项目(41372135) 国家级大学生创新创业训练计划项目(201510424008)~~
【分类号】：P512.2

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