广东湛江湖光岩玛珥湖全新世磁化率变化特征及其环境意义  

Magnetic Susceptibility of Huguangyan Maar Lake since the Holocene and Its Environmental Significance

作　　者：吴旭东[1,2] 沈吉[1] 汪勇[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008 [2]中国科学院研究生院,北京100049

出　　处：《热带地理》2011年第4期346-352,共7页Tropical Geography

基　　金：国家自然科学基金资助项目(40872117)

摘　　要：对湖光岩玛珥湖沉积物进行了低频磁化率(下称磁化率)、粒度组合特征、烧失量以及磁化率随温度变化(κ-T)的分析。磁化率随温度变化的特征显示湖光岩沉积物中最主要的磁性矿物是磁铁矿;磁化率与黏土矿物含量呈正相关,反映了湖光岩沉积物中的磁性矿物主要赋存于黏粒组分中;全新世以来湖光岩地区的磁化率的低值指示湿润的气候条件,高值则反映了相对干旱的气候条件。湖光岩地区的早全新世季风较强,中全新世以来季风逐渐减弱,符合全新世季风演化的全球模式。最近2000多年以来磁化率的大幅度增加可能与人类活动的增强有关,是人类活动和气候因素共同作用的结果。The magnetic susceptibility, grain size assemblage, loss on ignition and variations of magnetic susceptibility versus temperature （κ-T） of lacustrine sediment from Huguangyan Maar Lake are analyzed in this paper. The κ-T curves show that main magnetic mineral is magnetite, magnetic susceptibility has positive correlation with clay mineral content, that proves that magnetic minerals of Huguangyan Maar Lake are mainly related to clay minerals. Low magnetic susceptibility values indicate wet climate, while high magnetic susceptibility values indicate dry climate since the Holocene. The monsoon intensified during the early Holocene and weakened since the middle Holocene, that is in accord with the global evolutionary pattern of the Holocene monsoon. The intense increase of magnetic susceptibility in recent 2000 years indicates intensified human impact, it is a result from both human activity and climate change.

关 键 词：磁化率 粒度 烧失量 全新世 古气候 湖光岩玛珥湖 

分 类 号：P532[天文地球—古生物学与地层学]