西南印度洋龙旂热液区沉积物地球化学特征及其指示意义  

Geochemical Characteristics and Indicative Significance of Sediments in the Longqi Hydrothermal Area of the Southwest Indian Ocean

作　　者：陈延军 李萍 徐元芹 高伟 刘杰 CHEN Yanjun;LI Ping;XU Yuanqin;GAO Wei;LIU Jie(First Institute of Oceanography,MNR,Qingdao 266061,China;Laboratory for Marine Geology,Qingdao Marine Science and Technology Center,Qingdao 266237,China)

机构地区：[1]自然资源部第一海洋研究所,山东青岛266061 [2]青岛海洋科技中心海洋地质过程与环境功能实验室,山东青岛266061

出　　处：《海洋科学进展》2024年第3期532-544,共13页Advances in Marine Science

基　　金：中国大洋协会“十三五”资源环境项目(DY135-E2-1-01)。

摘　　要：热液区沉积物通常蕴含着热液活动的相关信息,其地球化学特征可以指示物质来源。本文以龙旂热液区及其周边区域沉积物样品为研究对象,通过沉积物主微量元素地球化学分析,利用元素含量特征分析、特征元素三角图解、稀土元素标准化图解、元素热液贡献计算等方法,探讨了沉积物的物质来源与热液贡献。结果表明,研究区沉积物主要为钙质生源沉积物和含碎屑沉积物;含碎屑沉积物TFe2O3、MnO、P2O5、Ni、Cr、V、Cu含量高于钙质生源沉积物,稀土元素总量整体偏低,呈轻稀土富集、Eu负异常、Ce负异常的特点;由钙质生源、火山碎屑、热液组分及海水作用形成的化学元素构成了主要沉积物物质来源;在含碎屑沉积物中,不同样品热液贡献呈现差异性;热液区对沉积物样品主要影响元素为Fe、Mn。Hydrothermal deposits usually contain some information about hydrothermal activities,and their geochemical characteristics can indicate material sources of deposits.This study took sediment samples from the Longqi hydrothermal area and surrounding areas as the research object,and discussed the material sources of sediments and the hydrothermal contributions from elements in hydrothermal sediments by using element compositions.The results showed that the sediments in the study area were mainly calcareous biogenic sediments and detrital sediments.The contents of TFe2O3,MnO,P2O5,Ni,Cr,V and Cu in the detritus sediments were higher than those in the calcareous biogenic sediments.The total amount of rare earth elements of the sediments was generally low,showing the characteristics of light rare earth enrichment,negative Eu and Ce anomalies.The main sources of sediment materials are calcareous biogenic,pyroclastic,hydrothermal components and seawater.In the detrital sediments,the hydrothermal contributions of different samples were different.The main elements of the sediment samples affected by the hydrothermal zone were Fe and Mn.

关 键 词：西南印度洋中脊 地球化学 物质来源 热液活动 龙旂热液区 

分 类 号：P736.4[天文地球—海洋地质]