显生宙以来汞浓度异常评估及碳汞耦合关系的初步研究  

Preliminary Study on the Assessment of Mercury Concentration Anomalies Since the Phanerozoic and the Coupling Relationship Between Carbon and Mercury

作　　者：何柯衡 崔珉铭 HE Keheng;CUI Minming(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081 [2]中国科学院大学,北京100049

出　　处：《地球与环境》2025年第1期1-13,共13页Earth and Environment

基　　金：中国科学院百人计划项目。

摘　　要：在漫长的地球历史中,生物大灭绝事件屡次发生,特别是显生宙以来至少发生过5次全球性生物大灭绝,汞(Hg)作为将这些事件与大火成岩省喷发连接起来的关键线索,在地质记录中备受关注。然而,先前的研究多倾向于聚焦重大事件导致的特定时期内汞浓度异常现象,缺乏对汞在地质历史时期大尺度下演化的整体性认识。此外,总有机碳(TOC)作为沉积物中汞的主要载体,二者之间的协同演化关系也存有许多未知。因此,本研究以沉积地球化学与古环境项目数据库中汞和碳的记录和近年来5次生物大灭绝事件的文献数据为研究对象。通过观察各时期元素浓度变化,发现SGP数据库记录的最高的4个Hg峰值分别位于508、401、298和111 Ma;通过Spearman′s rho相关系数和回归分析,发现沉积物中Hg与TOC的浓度之间存在正相关关系。对比前人对地质记录中汞浓度异常的解释和沉积物中Hg与TOC关系的研究,我们探讨了造成沉积物中Hg异常的可能因素,认为4个时期Hg含量的高值可能并不都是火山作用造成的;另外,我们发现碳酸盐岩和硅质碎屑岩中Hg与TOC含量的数据在分区拟合下效果最佳,说明在不同沉积环境下沉积物中Hg与TOC含量可能具有不同的耦合关系。Biological mass extinctions have occurred repeatedly throughout Earth′s long history,especially since the Phanerozoic,when at least five global mass extinctions have occurred,and mercury(Hg)has attracted much attention in the geologic record as a key clue linking these events to the eruption of large igneous provinces.However,previous studies have tended to focus on Hg concentration anomalies over specific periods of time with major events occurred,and have lacked a holistic understanding of the evolution of Hg over large scales of geologic history.In addition,total organic carbon(TOC)as the main host for mercury in sediments,there are many unknowns about the co-evolutionary relationship between TOC and Hg.Therefore,this study is based on the Hg and carbon records in The Sedimentary Geochemistry and Paleoenvironments Project(SGP)database and data for the Big Five mass extinctions in recent years to solve the above problems.By observing the changes of elemental concentration in each period,this study found that Hg and TOC had similar trends during the Phanerozoic period,and the four highest Hg peaks recorded in the SGP database were found to be located at 508,401,298,and 111 Ma;And a positive correlation between Hg and TOC concentrations in sediments was found by Spearman′s rho correlation coefficient and regression analysis.Comparing previous interpretations of Hg concentration anomalies in the geologic record and studies of the relationship between Hg and TOC in sediments,we explored possible factors contributing to Hg anomalies in sediments,and we suggest that:(1)The sources of Hg in the environment are complex and varied,and anomalous accumulations of Hg in sedimentary rocks do not always originate from the LIP,and a combination of possible factors needs to be considered when interpreting Hg concentration anomalies;(2)The relationship between Hg and TOC concentrations in different lithologies shows significant differences.Data on Hg and TOC concentrations in carbonatites and siliciclastic clastic rocks wor

关 键 词：显生宙 环境演化 总有机碳 汞 元素耦合 

分 类 号：P595[天文地球—地球化学]