Modern Climatic Signals Recorded in Xincuo Lake Sediments in Zoige Basin, Eastern Tibetan Plateau, China

Abstract

依据湖泊沉积记录进行古气候环境要素定量复原是过去全球变化研究的重要内容.本文通过若尔盖盆地兴措湖近代湖泊沉积特征、沉积物总有机碳及其同位素指标分析,并与器测气象资料进行比较,对兴措湖近代湖泊沉积物中有机碳及其同位素指标所代表的气候环境信息进行了定量研究.在此基础上,建立了兴措湖沉积物总有机碳及其同位素记录与对应的降水和气温间的函数关系.为定量恢复该区长尺度历史时期古气候环境特征提供了基础.;Climatic proxy of stable carbon isotope, together with total organic carbon content, in organic matter in lake sediment is one of the most effective methods to reconstruct past climatic evolutionary sequences. By coupling the indexes of TOC and δ¹³C_org in Xingcuo lake sediments and instrumental meteorological data in Zoige Basin, Eastern Tibetan Plateau and by building relative function relations among them, we probed quantitatively modern climatic signals recorded in those indexes. The results showed that there were remarkable relations between contents of TOC and precipitation, δ¹³C_org and air temperature, of which coefficence reaches to-0.67 and -0,75, respectively. Besides, we also demonstrated that average variation between contents of TOC and precipitation (dTC/dP) is -0.046%·mm^-1 and -0.84‰·℃^-1 for δ¹³C_org and air temperature (dδC/dT). According to the above, relative function relations among them were built.