金沙江河流悬浮物的元素地球化学特征及其地质意义

Geochemistry Characteristic and Geological Significance of Suspended Particle Matters in Jinsha River

系统测定了金沙江和岷江16个采样点的河流悬浮物的稀土元素和微量元素含量。结果表明,金沙江悬浮物的稀土元素地球化学特征与世界其他河流基本相同,而(LREE/HREE)N值较低,其主河道悬浮物的(Eu/Eu*)N略高于北美页岩;支流悬浮物的(La/Yb)N和(Eu/Eu*)N差别较大,亦与主河道有较大差别。受流域内矿化带和采矿影响,悬浮物中Cs、Cu、Pb、Bi、Sn、Ti、V、Cu、Cr、Co相对富集。岷江悬浮物的地球化学特征与金沙江主河道相似。综合研究表明,悬浮物的元素地球化学特征主要受控于流域内出露岩性,金沙江支流、通天河(直门达)到树地桥段、攀枝花到水富段的物源有所不同,悬浮物的地球化学特征有所差异。金沙江段是长江中下游重要物质来源,对中下游物源及元素地球化学特征分析也有一定的借鉴价值。

The content of rare earth element （REE） and trace elements of 16 Suspended Particulate Matters （SPM） of Jinsha River and Min River was measured in this thesis. REE Chondrite-normalized curves of the samples are similar to the other important rivers in the world, except （LREE/HREE） N is relatively low. （Eu/Eu^＊）N values of the main channel of Jinsha River are slightly higher than North America Shale. The values （La/Yb）N and （Eu/ Eu^＊）N are clearly different in different branches, and different from the main channel. Influenced by the mineralizing-zone and mining activities, Cs, Cu, Pb, Bi, Sn, Ti, V, Cu, Cr, Co are enriched in SPM. The geochemical characteristic of Min River are similar to the main channel of Jinsha River. The study shows that the geochemical characteristics of SPM element are mostly controlled by souce rock of the area. The SPM resources of the branches, the main channel between Tongtianhe （Zhimenda） and Shudiqiao, and the main channel from Panzhihua to Shuifu are different; therefore geochemical characteristic of the samples are variance. Jinsha River is important resource of the middle and low parts of Yangzi River. This thesis is valuable for the research of the middle and low parts of Yangze River.