黄河源区典型湖泊希门错沉积物的地球化学特征及其环境意义  

Element Geochemistry of Lake Sediment from Ximencuo Lake in the Qinghai Tibet Plateau and Its Significance for Climate Variation

作　　者：沈德福[1] 李世杰[2] 姜永见[2] 

机构地区：[1]宁德师范学院旅游系,福建宁德352100 [2]中国科学院南京地理与湖泊研究所,江苏南京210008

出　　处：《云南师范大学学报（自然科学版）》2015年第3期62-69,共8页Journal of Yunnan Normal University:Natural Sciences Edition

基　　金：国家科技基础性工作专项基金资助项目(2006FY110600);宁德师范学院基金资助项目(2013F56;2013Y006)

摘　　要：湖泊沉积是历史时期气候波动与流域环境变化的记录器.采集黄河源区希门错沉积物,对岩芯的有机质和地球化学元素进行了分析,得到该地近1 720年以来的环境变化记录.结果显示希门错沉积物47cm柱状岩芯的环境演化过程可分为四个阶段:32cm以下(900AD之前),该阶段为气温变冷阶段,降水多;32-20cm之间(900-1300AD),该阶段为气温变暖阶段,和中世纪暖期相对应,降水减少;20-3.5cm之间(1300-1900AD),该阶段为气温变冷阶段,和小冰期较为吻合,降水较多且逐步减少;3.5-0cm(1900AD至今),这个时期为20世纪暖期,降水较少.磷元素含量在近20多年来增加较大,说明人类活动对流域的影响不断增强.在此之前的磷元素沉积含量低且稳定,指示该区域磷的背景值.Lake sediment is the recorder of historical climate fluctuation and basin environment change. This study collected Ximencuo Lake sediment in source area of the Yellow River, the or- ganic matter and geochemical elements of the core were analyzed,obtained nearly 1 720 a environ- ment changes. The results showed the environment evolution process of the core can be divided into four stages：below 32cm（before 900AD）,this stage corresponding to the cool and wet cli- mate;32~20 cm（900AD--1300AD）corresponding to the warming temperature was low and decrea- sing precipitation;between 20~3. 5 cm（1300-1900AD）,the stage is more consistent with the Little Ice Age,and precipitation gradually reduced;3.5~0 cm（since 1900AD）,this is the twentieth cen- tury warming period with increase temperature and reduced precipitation. Phosphorus content in- creased rapidly in the last 20 years,it reflects the human continuously enhancing activities. But before the time, the P deposition content is low and stable,indicating the natural background of regional phosphorus.

关 键 词：希门错 沉积岩芯 元素地球化学特征 环境变化 

分 类 号：P53[天文地球—古生物学与地层学]