广东湛江湖光岩玛珥湖沉积物主、微量元素对近四百年气候环境变化的记录  

Records of Major and Trace Elements in the Sediment of Huguangyan Maar Lake,Zhanjiang,Guangdong Province,on Climate and Environmental Changes in the Past 400 Years

作　　者：胡锋 李社红[1] 吴梅 韩桥 郝立凯 HU Feng;LI She-hong;WU Mei;HAN Qiao;HAO Li-kai(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;University of Chinese Academy of Sciences,Bejing 100049,China;CAS Center for Excellence in Quaternary Science and Global Change,Xi'an 710061,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 [3]中国科学院第四纪科学与全球变化卓越创新中心,西安710061

出　　处：《矿物岩石地球化学通报》2022年第5期926-933,共8页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：中国科学院战略性先导专项(B类)课题(XDB40020400);中央引导地方科技发展资金项目(黔科中引地[2021]4028)。

摘　　要：湖泊沉积物的元素组成既能反映物质来源,也能较好记录气候环境变化。本文以广东湛江湖光岩玛珥湖沉积物为研究对象,采用电感耦合等离子体质谱仪分析其主要元素组成,通过因子分析得到其主成分元素组,并据此探究不同元素组分与气候环境的关系。结果表明,三个主成分元素组为:F1由Al、Fe、Rb、Sr和稀土元素组成,是湖区降水量和化学风化强度的良好指标;F2由Zn、Co、Cu、Mo等组成,其因子得分变化趋势与F1呈显著负相关性,这组元素属于湖泊内生沉积因子,与湖水的氧化还原性质密切相关,指示暖干气候条件;F3包括Ti、Ni、Cr、Zr,这类元素性质稳定,主要存在于矿物碎屑中,受地表径流影响,也与源区岩石的物理风化、水土流失程度密切相关,可以指示植被覆盖情况。结合最新的定年结果以及过去气候环境变化资料,对三个主成分变化特点进行分析,可将湖光岩地区近400年来的气候大致分为1614—1796年冷湿期、1796—1868年冷干期、1868—1927年冷湿期、1927—1967年冷干期和1967年至今总体向暖湿变化5个阶段,且农业活动的增强使沉积物中性质稳定元素的含量显著增加。The elemental composition of lake sediments reflects the material source of sediments and records the regional climate and environmental changes well.In this paper,the sediments of Huguangyan Maar Lake in Zhanjiang,Guangdong,were taken as the research object,the element groups of the sediments were determined using the principal component analysis,and the relationships between element groups and changes of climate and environment were discussed.The results show that there are three principal component groups with different indicative meanings in the sediments:the principal component F1,composed of Al,Fe,Rb,Sr and rare earth elements,is a good indicator of precipitation and chemical weathering intensity in the lake area;the principal component F2 is composed of Zn,Co,Cu,Mo and etc.,it has a significant negative correlation with F1 and is closely related to the redox properties of lake water,indicating that F2 belongs to lake endogenous sedimentary factors,reflecting the warm and dry climatic conditions;the principal component F3 is composed of Ti,Ni,Cr and Zr,which are stable in nature and mainly present in mineral debris,F3 is affected by surface runoff and is closely related to the degree of rock physical weathering and soil erosion in the source area,and can indicate the vegetation coverage.Based on the latest sediment dating results,combined with the past climate and environmental change data,and through the analysis of the change characteristics of the three principal components,the climate in the Huguangyan area in the past 400 years can be roughly divided into a cold wet period from 1614 to 1796,a cold dry period from 1796 to 1868,a cold wet period from 1868 to 1927,a cold dry period from 1927 to 1967,and an overall warm wet period from 1967 to present.In addition,this paper found that the enhanced human agricultural activities increase the content of stable elements in sediments significantly.

关 键 词：沉积物 元素组成 主成分分析 气候变化 

分 类 号：X142[环境科学与工程—环境科学]