胶州湾沉积物的不同相态主量元素含量及铁同位素组成初探  

Content of Major Elements and Iron Isotopic Compositions in Different Fractions of Jiaozhou Bay Sediments

作　　者：孙子威 肖媛媛 张跃[1] 刘瑾 SUN Ziwei;XIAO Yuanyuan;ZHANG Yue;LIU Jin(College of Chemistry and Molecular Engineering,College of Marine Science and Biological Engineering,Qingdao University of Science and Technology,Qingdao 266042,China;Qingdao National Laboratory for Marine Science and Technology,Qingdao 266061,China;Key Laboratory of Marine Geology and Environment,Center for Ocean Mega-Science,Public Technology Service Center,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China)

机构地区：[1]青岛科技大学化学与分子工程学院,海洋科学与生物工程学院,山东青岛266042 [2]青岛海洋科学技术国家重点实验室,山东青岛266061 [3]中国科学院海洋研究所地质与环境重点实验室,海洋大科学研究中心,海洋研究所公共技术服务中心,山东青岛266071

出　　处：《青岛科技大学学报（自然科学版）》2024年第2期38-46,共9页Journal of Qingdao University of Science and Technology:Natural Science Edition

基　　金：青岛海洋科学与技术试点国家实验室“十四五”重大项目(LSKJ202202905);国家自然科学基金项目(41776069);中国科学院战略性先导科技专项项目(B类)(XDB42020302).

摘　　要：沉积物是物源、沉积环境、生源过程等多因素影响下的产物,不同元素进入沉积物的方式不同导致其赋存在不同的相态中,通过研究不同相态沉积物的元素丰度及同位素组成,可以揭示由于多种过程混合所掩盖的生物、物理及化学信息。本研究通过选择性化学提取法,对胶州湾沉积物进行了分级提取,包括碳酸盐结合态、易还原的氧化物态、可还原的氧化物态、磁铁矿态和残留态。测试结果表明:主量元素主要赋存在残留态中,但在非残留态中不同程度保留有Ca、Fe、Mg、Mn和P。结合胶州湾沉积物中的常见矿物成分,除了之前研究已介绍的不同相态的目标矿物组成,推测易还原的氧化物态的潜在矿物还有独居石和磷灰石;可还原的氧化物态的潜在矿物还有褐铁矿;磁铁矿态的潜在矿物还有钛铁矿;部分硅酸盐矿物也存在于易还原的氧化物态和可还原的氧化物态中。残留态富集了重铁同位素,继承了物源区的特征,并且全组分的铁同位素主要受控于残留态;活性铁组分的铁同位素由于受到了非陆源组分的影响,导致同位素变化。Sediments are the products influenced by multiple factors(such as,provenance,depositional environment,and biogenic process),different elements enter sediments in different ways,resulting in their occurrence in different fractions.By studying the elements abundance and isotopic compositions of sediments,it can reveal biology,physical and chemical information obscured by the mixing of various processes.In this study,the sediments of Jiaozhou Bay were fractionally extracted,including carbonate combined fraction,easily reducible oxide fraction,reducible oxide fraction,magnetite fraction and residual fraction.The results of element content in different fractions show that the major elements are mainly present in the residual fraction,but Ca,Fe,Mg,Mn and P are present in the non-residual fractions to varying degrees.Combined with the common mineral compositions in the sediments of Jiaozhou Bay,in addition to the target mineral compositions of different fractions introduced in previous studies,it is speculated that the potential minerals in the easily reducible oxide fraction may include monazite and apatite.The potential minerals in the reducible oxide fraction may include limonite.The potential minerals in the magnetite fraction may include ilmenite.Some silicate minerals also exist in easily reducible oxide fraction and reducible oxide fraction.The residual fraction is enriched with heavy iron isotope,inheriting the characteristics of the provenance area,and the iron isotope of the total fraction is mainly controlled by the residual fraction.The iron isotope of the active iron fraction is affected by the non-terrestrial compositions.

关 键 词：胶州湾 沉积物 连续提取 铁同位素 

分 类 号：P736.41[天文地球—海洋地质]