TY - JOUR
T1 - Lithium distribution and isotopic fractionation during chemical weathering and soil formation in a loess profile
AU - Tsai, Pei Hsuan
AU - You, Chen Feng
AU - Huang, Kuo Fang
AU - Chung, Chuan Hisung
AU - Sun, You Bin
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/6/15
Y1 - 2014/6/15
N2 - Lithium (Li) is a fluid-mobile element and δ7Li in secondary deposits represents an excellent proxy for silicate weathering and authigenic mineral formation. The soil samples from 1205 to 1295cm in the Weinan profile, one of the best developed loess-paleosol sequences covering the last glacial-interglacial climatic cycle, were collected and chemically separated into detritus and carbonate fractions for subsequent analyses of Li, δ7Li, major and trace elements. Other desert specimens (i.e., Qaidam Desert, Tengger Desert, Badain Juran Desert and Taklimakan Desert) near the Chinese Loess Plateau (CLP) and various standard clays were analyzed for assisting provenance determination. The Li and δ7Li distributions in the detritus are rather homogeneous, 1.4-2.0μg/g and +2.5‰ to +4.7‰, respectively, compared with the carbonate fraction. The detrital δ7Li varies systematically with magnetic susceptibility and grain size changes, reflecting significant Li isotopic variation associated with sources and mineralogy of detrital material. On the other hand, Li and δ7Li in carbonates show large changes, 781-963ng/g and -4.1‰ to +10.2‰, respectively. These carbonate δ7Li correlated well with the estimated index of chemical weathering, as a result of Li mobilization and soil formation during chemical weathering.
AB - Lithium (Li) is a fluid-mobile element and δ7Li in secondary deposits represents an excellent proxy for silicate weathering and authigenic mineral formation. The soil samples from 1205 to 1295cm in the Weinan profile, one of the best developed loess-paleosol sequences covering the last glacial-interglacial climatic cycle, were collected and chemically separated into detritus and carbonate fractions for subsequent analyses of Li, δ7Li, major and trace elements. Other desert specimens (i.e., Qaidam Desert, Tengger Desert, Badain Juran Desert and Taklimakan Desert) near the Chinese Loess Plateau (CLP) and various standard clays were analyzed for assisting provenance determination. The Li and δ7Li distributions in the detritus are rather homogeneous, 1.4-2.0μg/g and +2.5‰ to +4.7‰, respectively, compared with the carbonate fraction. The detrital δ7Li varies systematically with magnetic susceptibility and grain size changes, reflecting significant Li isotopic variation associated with sources and mineralogy of detrital material. On the other hand, Li and δ7Li in carbonates show large changes, 781-963ng/g and -4.1‰ to +10.2‰, respectively. These carbonate δ7Li correlated well with the estimated index of chemical weathering, as a result of Li mobilization and soil formation during chemical weathering.
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U2 - 10.1016/j.jseaes.2014.02.001
DO - 10.1016/j.jseaes.2014.02.001
M3 - Article
AN - SCOPUS:84895757835
SN - 1367-9120
VL - 87
SP - 1
EP - 10
JO - Journal of Asian Earth Sciences
JF - Journal of Asian Earth Sciences
ER -