ICP-OES研究罗布泊“大耳朵”湖相沉积物常量元素地球化学特征及环境意义

Element Geochemistry of Lake Sediments from L07-10 in the“Great Ear”Area of Lop Nur and Its Significance for Climate Variation Change with ICP-OES

光谱分析技术应用于地球化学元素分析研究,为湖泊沉积物反演环境变化提供了更多的环境信息。以罗布泊＂大耳朵＂区域L07-10剖面沉积物为研究对象,利用ICP-OES对常量地球化学元素进行了测定分析,结合AMS进行14 C年代学测定,初步探讨了该地区16.34ka BP以来的气候环境变化。结果表明：常量元素地球化学特征可以灵敏的指示环境变化,元素环境代用指标很好的反映了该地区的气候变化过程。总体来看,常量元素分布特征指示16.34ka BP以来,罗布泊区域气候经历了暖湿-暖干-凉湿-暖干的变化,在8.09-6.34ka BP期间发生了一次较明显的短期升温阶段,这一时期气候温暖干燥,降水减少,与全球及区域气候变化相关记录相吻合。近2 000a以来气候总体温暖,降水量减少,源区水热条件变差,水运的搬运能力降低。

Spectral analysis techniques were applied to geochemical element analysis to provide additional environmental data about evolution of salt lakes and climate change.The elements composition of lake sediments from L07-10 in the＂Great Ear＂Area of Lop Nur was analyzedby using Inductively Coupled Plasma Optical Emission Spectrometer（ICP-OES）and from 14 Ccarbon dating by using the EN accelerator mass spectrometry（AMS）.This paper estimated the climate change in this region since 16.34 ka BP.Results demonstrate that the geochemical characteristics of major elements at all sediment levels can indicate environmental change sensitivity,and element composition is more sensitive to climate change.Overall,climate succession since 16.34 ka BP had been：warm-wet,warm-dry,cold-wet and warm-dry.From 8.09-6.34 ka BP,the climate obviously heated up and was warmer and drier,which is consistent with global and regional climate change estimates from other studies.By about 2ka BP,the climate becomes warmer and drier and the water carrying capacity of this lake was reduced.