Paleoclimatic indication of X-ray fluorescence core-scanned Rb/Sr ratios: A case study in the Zoige Basin in the eastern Tibetan Plateau  

作　　者：Hanfei YANG Yan ZHAO Qiaoyu CUI Weihe REN Quan LI 

机构地区：[1]Key Laboratory of L and Surface Pattern and Simulation,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China [2]University of Chinese Academy of Sciences Beijing 100049,China

出　　处：《Science China Earth Sciences》2021年第1期80-95,共16页中国科学（地球科学英文版）

基　　金：supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA20070101);the National Natural Science Foundation of China(Grant Nos.41690113&41888101);the National Key Research and Development Program of China(Grant No.2016YFA0600501)。

摘　　要：The X-ray fluorescence(XRF)core-scanned Rb/Sr ratios of lake sediments have been widely used as a proxy for chemical weathering intensity and past climate change.However,some factors could affect Rb/Sr ratios,causing misinterpretation and limiting its application.In this study,we present a high-resolution XRF core-scanned Rb/Sr record of core ZB13-C1 from the Zoige Basin in the eastern Tibetan Plateau.To validate its application,we correlated this record with the chemical index of alteration(CIA)and other paleoclimatic proxies.Our results showed that(1)the core-scanned Rb/Sr ratios and CIA were reliable proxies of chemical weathering intensity in fine-grained sedimentary sequences;(2)the low values of corescanned Rb/Sr ratios and CIA were significantly correlated with high total organic carbon content,arboreal pollen content,carbonate content,and C/N ratios,confirming its reliability as a proxy for the Asian summer monsoon intensity;(3)the corescanned Rb/Sr ratios at core depths of 25–0.3 and 56–47 m were unable to reliably reflect chemical weathering intensity due to both the grain-size effect and the low test accuracy.Our study highlights the need for mutual verification of multiple indicators before accurately applying Rb/Sr as a paleoclimatic proxy in other similar study areas.

关 键 词：Rb/Sr ratios XRF core scanning Lake sediment Tibetan Plateau Paleoclimatic indication 

分 类 号：P532[天文地球—古生物学与地层学]