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研究稀土元素在流体中的地球化学行为及其控制因素 ,对利用稀土示踪与流体有关的地球化学过程具有重要意义。海底高温流体稀土组成研究表明 ,不同背景、岩性热液系统喷口流体的稀土含量差别较大 ,与海水之间可达几个数量级 ,但配分模式却非常类似 ,即普遍具有 LREE富集、高的正 Eu异常特征。流体的稀土组成与岩石或矿物的蚀变程度、结构构造有关 ,同时受流体的温压、p H值、Eh值、络合介质种类等因素的影响 ,其配分模式是流体循环、迁移过程中络合、吸附、矿物沉淀等不同因素共同作用而再次调整的结果。正 Eu异常作为高温流体的特征标志 ,可以用来示踪与高温流体有关的地球化学作用过程 ,同时 Y/Ho比值、负 Ce异常可以用来示踪与流体 /海水混合有关的化学过程。
Studying the geochemical behavior of rare earth elements in fluids and their controlling factors are of great significance to the use of rare earth tracer for fluid-related geochemical processes. The study on composition of seafloor high-temperature fluid rare earths shows that the rare earth content of the fluid in the vents of lithologic hydrothermal system varies greatly with different backgrounds and can reach several orders of magnitude with seawater, but the partitioning patterns are very similar, ie generally have LREE enrichment, high The positive Eu anomaly features. The composition of rare earths in fluids is related to the degree of alteration and structural structure of rocks or minerals, and is influenced by factors such as the temperature and pressure of fluid, p H value, Eh value and the type of complexing medium. The distribution pattern of fluids is fluid circulation and migration Complexation, adsorption, mineral precipitation and other factors together to adjust the results again. As a hallmark of high-temperature fluids, the positive Eu anomalies can be used to trace the geochemical processes associated with high-temperature fluids. The Y / Ho ratio and negative Ce anomalies can be used to trace the chemical processes associated with fluid / seawater mixing.