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通过对东菲律宾海近代深海黏土沉积物粒度、稀土元素组成及其赋存状态和铀系同位素年代学的综合研究,探讨了研究区沉积物的特征与物质来源.主要结论包括:(1)沉积速率低、分选性和磨圆度较差、细粉砂以上粒级含量高,表明研究区沉积物物源相对匮乏且没有经过长途搬运.(2)稀土元素总量较为富集,其页岩标准化配分模式具有较弱的重稀土富集、不同程度的Ce负异常和Eu正异常特征.(3)有无结壳发育站位沉积物中稀土元素的赋存状态特征较一致,主要赋存于残渣态和铁锰氧化物态中.残渣态表现出轻稀土元素的相对富集、Ce和Eu的正异常特征;而在铁锰氧化物态中,重稀土元素则相对富集,Ce呈负异常.(4)有无结壳站位沉积物在上述各指标间均存在一定的差异.(5)综合上述特征及源区判别分析,认为所研究沉积物主要来自于当地及附近火山物质的蚀变,同时也受较小程度的风尘和(或)河(洋)流输入陆源物质的影响.
The characteristics and material sources of the sediments in the study area are discussed through the comprehensive study of the sediment grain size, REE composition and its occurrence state and uranium-derived isotopic chronology in the deep clay of the East Philippine Sea. The main conclusions include: (1) Low rate, poor sorting and roundness, high grain size above fine silt, indicating that the source of sediment in the study area is relatively scarce and has not been transported for long distances. (2) The total amount of rare earth elements is relatively abundant The rock normalized distribution pattern has weaker heavy rare earth enrichment, different degrees of negative anomalies of Ce and positive Eu anomalies. (3) The occurrence characteristics of rare earth elements in sediments with or without crustal development are consistent, In the residual state and in the Fe-Mn oxide state.The residual state shows the relative enrichment of LREE, positive anomalies of Ce and Eu, whereas in the Fe-Mn oxide state, heavy rare earth elements are relatively enriched and Ce (4) There is a certain difference in the sediment of the crusting stations between the above indexes. (5) Based on the above characteristics and the discriminant analysis of the source area, it is considered that the sediments studied mainly come from the volcano Material alteration, but also by comparison The degree of dust and (or) River (ocean) stream input affect terrestrial species.