The influence of carbonate precipitation on riverine magnesium isotope signals: New constrains from Jinsha River Basin, Southeast Tibetan Plateau

doi:10.1016/j.gca.2019.01.005

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院新生代地质与环境重点实验室

	The influence of carbonate precipitation on riverine magnesium isotope signals: New constrains from Jinsha River Basin, Southeast Tibetan Plateau
	Zhao, Tong 1,2,3; Liu, Wenjing 1,2,3; Xu, Zhifang 1,2,3; Sun, Huiguo 1,2,3; Zhou, Xiaode 1,2,3; Zhou, Li 4; Zhang, Jiangyi 1,2; Zhang, Xuan 1,2,3; Jiang, Hao 1,2,3; Liu, Taoze 5
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2019-03-01
卷号	248 页码:172-184
关键词	River geochemistry Chemical weathering Mg isotopes Secondary carbonate precipitation
ISSN号	0016-7037
DOI	10.1016/j.gca.2019.01.005
英文摘要	Magnesium isotope behavior in dissolution and precipitation reactions during chemical weathering have been well documented. However, mechanisms of mineral dissolution and precipitation impact on the riverine Mg isotope composition under different climatic and geology background are not well constrained, which limits Mg isotope application in weathering research. Mg isotopic compositions for solute and suspended sediments in Jinsha River Basin, located in Tibetan Plateau, China, were examined to address this issue. The delta Mg-26 values for dissolved loads range from -1.67 parts per thousand to -0.5 parts per thousand, and the suspended loads show systematically heavier Mg isotope compositions (-1.15 parts per thousand to -0.06 parts per thousand). Conservative mixing between different rock weathering end-members fails to fully explain Mg isotopic composition variation of Jinsha River waters based on mass balance and mixing model with the river geochemistry data. Mg in rivers draining dominantly carbonate and evaporite is isotopically heavier compared with the value of catchment bedrocks, and water pH and delta Mg-26 values are negatively correlated in carbonate (calcite and dolomite) oversaturated river waters, which suggests the precipitation of secondary carbonate as an important mechanism driving the delta Mg-26 of dissolved loads heavier. For carbonate unsaturated waters, Mg concentrations and delta Mg-26 values are intermediate between those of silicate dominated basins and carbonate oversaturated waters. The results suggest two possible different mechanisms controlling river solute delta Mg-26 values: fractionation during carbonate precipitation incorporating of Mg; and conservative mixing between a solute end-member formed from carbonate precipitation and end-members from rock weathering. This study provides new evidence and insights in carbonate precipitation processes regulating river Mg isotope signature and its potential influence on Mg cycling. (C) 2019 Elsevier Ltd. All rights reserved.
资助项目	"Strategic Priority Research Program" of the Chinese Academy of Sciences[XDB26000000] ; "Strategic Priority Research Program" of the Chinese Academy of Sciences[XDB15010405] ; National Natural Science Foundation of China[91747202] ; National Natural Science Foundation of China[41730857] ; National Natural Science Foundation of China[41402323]
WOS关键词	MG ISOTOPES ; CHEMICAL-COMPOSITION ; WEATHERING PROCESSES ; FRACTIONATION ; GEOCHEMISTRY ; CHINA ; CHEMISTRY ; CALCITE ; ISLAND ; DIFFERENTIATION
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000457972800011
资助机构	"Strategic Priority Research Program" of the Chinese Academy of Sciences ; "Strategic Priority Research Program" of the Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; "Strategic Priority Research Program" of the Chinese Academy of Sciences ; "Strategic Priority Research Program" of the Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; "Strategic Priority Research Program" of the Chinese Academy of Sciences ; "Strategic Priority Research Program" of the Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; "Strategic Priority Research Program" of the Chinese Academy of Sciences ; "Strategic Priority Research Program" of the Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/90518]
专题	地质与地球物理研究所_中国科学院新生代地质与环境重点实验室
通讯作者	Liu, Wenjing; Xu, Zhifang
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Cenozo Geol & Environm, Beijing 100029, Peoples R China 2.CAS Ctr Excellence Life & Paleoenvironm, Beijing 100044, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.China Univ Geosci, State Key Lab Biogeol & Environm Geol, Wuhan 430074, Hubei, Peoples R China 5.Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550002, Guizhou, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Tong,Liu, Wenjing,Xu, Zhifang,et al. The influence of carbonate precipitation on riverine magnesium isotope signals: New constrains from Jinsha River Basin, Southeast Tibetan Plateau[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2019,248:172-184.
APA	Zhao, Tong.,Liu, Wenjing.,Xu, Zhifang.,Sun, Huiguo.,Zhou, Xiaode.,...&Liu, Taoze.(2019).The influence of carbonate precipitation on riverine magnesium isotope signals: New constrains from Jinsha River Basin, Southeast Tibetan Plateau.GEOCHIMICA ET COSMOCHIMICA ACTA,248,172-184.
MLA	Zhao, Tong,et al."The influence of carbonate precipitation on riverine magnesium isotope signals: New constrains from Jinsha River Basin, Southeast Tibetan Plateau".GEOCHIMICA ET COSMOCHIMICA ACTA 248(2019):172-184.