辽河口沉积物地球化学特征与物源分析

发布时间：2018-03-11 18:13

本文选题：辽河口　切入点：地球化学　出处：《中国地质大学(北京)》2016年硕士论文　论文类型：学位论文

【摘要】：辽河口是指辽河在辽宁省盘锦市入海口处,每年沉积着来自河北省、内蒙古自治区、吉林省和辽宁省等四省区大量陆源碎屑。本文将通过利用地球化学、多元统计等多种方法对辽河口沉积物进行研究,探讨了辽河口沉积物粒度特征、元素地球化学特征、源区化学风化程度及气候状况、源岩属性及物质来源、源区构造背景等。结果表明：1.辽河口沉积物的类型有粘土质粉砂、砂质粉砂、粉砂质砂三种,其中粘土质粉砂为最主要类型；平均粒径为5.76φ),分选系数平均值为2.34,偏态平均值为5.76,峰态平均值为4.92；频率曲线均为单峰,众数粒径在10μm左右；C-M曲线表明沉积物以均匀悬浮为主,由此推断辽河口沉积环境稳定,水动力条件弱,物源单一。2.辽河口沉积物中的常量组分,含量及标准偏差最大的均为Si02,常量组分的垂向变化出现一定分层性,对比其他地区,辽河口沉积物更接近上地壳、中国大陆沉积物；辽河口沉积物中微量元素,含量最大是Ba,垂向变化同样也显出一定的分层性,与其他地区对比,辽河口沉积物更接近内蒙盖层平均化学组成：辽河口沉积物中的稀土元素总量比较低,配分曲线的斜率大于1,向右倾斜,富含轻稀土,与其他地区对比,辽河口沉积物更接近中国黄土。3.辽河口沉积物源区的气候条件整体上为寒冷干燥,气温变化存在波动,沉积物在沉积过程中气温变化为先变暖后变冷：辽河口沉积物的物源区可能包括内蒙古自治区的东部以及吉林省的西部,其中内蒙古自治区的东部物源贡献最大；辽河口沉积物源区的构造背景可能为大陆岛弧。
[Abstract]:Liaohe Estuary refers to the Liaohe River at the entrance of Panjin City, Liaoning Province, where a large amount of continental debris is deposited annually from four provinces, Hebei, Inner Mongolia Autonomous region, Jilin Province and Liaoning Province. Various methods such as multivariate statistics were used to study Liaohe estuary sediments. The grain size characteristics, element geochemical characteristics, chemical weathering degree and climatic conditions, source rock properties and material sources of Liaohe estuary sediments were discussed. The results show that there are three types of sediments in Liaohe estuary: clay silt, sandy silt and silty sand, among which clay silt is the most important type. The average particle size is 5.76 蠁 ~ (-1), the average separation coefficient is 2.34, the average deviation is 5.76, the average of peak is 4.92, the frequency curves are single peak, the C-M curve of mode particle size about 10 渭 m indicates that the sediment is mainly suspended uniformly, and the sedimentary environment of Liaohe estuary is stable. The hydrodynamic condition is weak and the material source is single .2.The major components in Liaohe Estuary sediment are Si02.The vertical variation of the main component is stratified. Compared with other areas, Liaohe estuary sediment is closer to the upper crust. In the sediments of the Liaohe estuary, the maximum content of trace elements is Ba.The vertical variation also shows a certain stratification, compared with other regions. Liaohe estuary sediments are closer to the average chemical composition of inner Mongolia caprock: the total amount of rare earth elements in Liaohe estuary sediments is relatively low, the slope of the partition curve is greater than 1, the slope of the partition curve is more than 1, and it is inclined to the right, rich in light rare earth elements, and compared with other regions. Liaohe estuary sediment is closer to loess in China. The climatic conditions of Liaohe estuary sediment source area are cold and dry, and the temperature changes fluctuate. In the process of sedimentation, the temperature change is first warming and then cooling: the source region of Liaohe Estuary probably includes the east of Inner Mongolia and the west of Jilin Province, in which the eastern part of Inner Mongolia contributes the most. The tectonic setting of Liaohe Estuary sediment source area may be continental island arc.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P512.2

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