Paleoclimatic application of spectral parameters to the eolian red clay of the Jianzha Basin,northeastern margin of the Tibetan Plateau  

作　　者：Chaofeng FU Ju’e TIAN Xinwen XU Yougui SONG Jun ZUO Feng WANG Lin CHEN Pengfei LI Xiaoke QIANG 

机构地区：[1]The School of Earth Science and Resources,Chang’an University,Xi’an 710054,China [2]State Key Laboratory of Loess and Quaternary Geology,Institute of Earth and Environment,CAS,Xi’an 710061,China [3]College of Urban and Environmental Science,Northwest University,Xi’an 710069,China [4]CAS Center for Excellence in Quaternary Science and Global Change,Xi’an 710061,China

出　　处：《Science China Earth Sciences》2024年第6期1952-1966,共15页中国科学（地球科学英文版）

基　　金：supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant Nos.2019QZKK0704&2019QZKK0101);the National Natural Science Foundation of China(Grant Nos.42272221&41772167);the State Key Laboratory of Loess and Quaternary Geology(Grant No.SKLLQG1905);the Central University Research Foundation,Chang’an University(Grant Nos.300102272901)。

摘　　要：Reflectance spectroscopy is rapid,inexpensive,and non-destructive and can provide important information about the mineralogy of rocks and sediments.We measured the reflectance spectroscopy of Miocene red clay deposits on the northeastern margin of the Tibetan Plateau,with the aim of developing a rapid methodology for detecting paleoclimatic changes.We obtained visible/near-infrared(VNIR)and short-wave infrared(SWIR)spectroscopy data from the red clay in the Jianzha Basin,and analyzed their relationship with independent paleoclimatic records,including mineral contents and environmental magnetic parameters.The results show that the VNIR parameters,including D500,D900,R500,and R900(where D and R represent the depth and reflectance of the absorption peaks around 500 and 900 nm,respectively)are temperature-sensitive and correlated with the magnetic susceptibility,frequency-dependent magnetic susceptibility,and the marine δ^(18)O record.The results of frequency-domain analysis of the VNIR parameters show that they reflect climate change on orbital timescales.SWIR parameters,such as AS1400,D1400/D1900 and D1900(where AS represents the asymmetry of the absorption peaks around1400 nm),are correlated with the illite and montmorillonite content,and they are sensitive to the weathering intensity.The spectral parameters of the eolian red clay in the Jianzha Basin reflect regional climatic changes caused by the uplift of the Tibetan Plateau at~8.5 Ma and global climatic cooling at~7.2 Ma,and thus they are applicable as both regional and global paleoenvironmental indicators.

关 键 词：Visible/near-infrared spectroscopy Short-wave infrared spectroscopy Paleoclimatic indicators Red clay Tibetan Plateau 

分 类 号：P532[天文地球—古生物学与地层学]