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本文对地矿部“海洋四号”科学考察船１９８７—１９８９年在东赤道太平洋ＣＣ区所取得的２７个深海表层沉积物样品进行Ｕ的地球化学分析，探讨了Ｕ在深海沉积中的地球化学行为。结果表明，不同类型沉积物的Ｕ含量不同，平均值由大至小的次序为含沸石粘土（２．１６×１０￣（－６））、硅质粘土（１．９５×１０￣（－６）），硅质软泥（１．６５×１０￣（－６））、钙质硅质粘土（１．５９×１０￣（－６）），在同类型沉积物中Ｕ的分散性较大；Ｕ在区域上的分布趋势与Ｃｏｒｇ类似而与ＣａＣＯ＿３相反，呈现出由南向北降低的趋势。与大陆边缘海、封闭、半封闭海的沉积物相比，深海沉积物的Ｕ含量最低，表现出Ｕ的亏损；Ｕ的晶体化学性质以及沉积物的物质来源决定了深海沉积物的Ｕ来源于海水和陆地，海水来源的Ｕ被自生粘土矿物和有机质吸附，陆源Ｕ与陆源粘土矿物有关，而较高的Ｅｈ和较低的Ｃｏｒｇ以及生物碎屑组份ＳｉＯ＿２、ＣａＣＯ＿３和Ｐ＿２Ｏ＿５对它起稀释作用都导致Ｕ的亏损，同时，Ｕ和Ｔｈ较大程度的分异也是深海沉积物的主要标志。
In this paper, 27 deep-sea surface sediment samples obtained from the “Ocean No. 4” scientific research ship in the Eastern equatorial Pacific CC from 1987 to 1989 were analyzed for geochemistry, and the geochemical characteristics of U in deep-sea sediments behavior. The results show that the contents of U in different types of sediments are different. The average order of the contents of the sediments is zeolite clay (2.16 × 10 ~ (-6)), siliceous clay (1.95 × 10 ~ (-6) ), Siliceous slime (1.65 × 10 ~ (-6)), and calcareous siliceous clay (1.59 × 10 ~ (-6)). The dispersibility of U in the sediments of the same type is larger ; The distribution trend of U in the area is similar to that of Corg but opposite to that of CaCO_3, showing a decreasing trend from south to north. Compared with the sediments in the coastal, closed and semi-closed continent of the continental margin, the sediments in deep sea have the lowest content of U and show the loss of U. The crystal chemistry of U and the source of sediment determine the origin of U land and sea, sea water is derived from the U raw clay minerals and organic matter adsorption, U and terrigenous terrestrial clay minerals, whereas a higher Eh and lower parts and Corg bioclast group SiO_2, CaCO_3 dilution effect and play it P_2O_5 All lead to the loss of U. Meanwhile, the greater degree of differentiation of U and Th is also the main sign of deep-sea sediments.