Sulfur and Oxygen Isotope Compositions of Dissolved Sulfate in tge Yangtze River during Higg Water Period and Its Sulfate Source Tracing
Li Xiaoqian
Liu Yunde
Zhou Aiguo
Zhang Bin
Abstract：Crustal weathering by sulfuric acid and its relationship with carbon cycling is a subj ect of greatest concern in the domain of global carbon cycling,with its key issue of the identification of riverine sulfate sources.In this study,stable sulfur and oxygen isotope compositions of riverine sulfate in the mainstream of the Yangtze River during rainy season are determined to trace the riverine sulfate sources and controlling factors.The SO4 2-concentration keeps increasing with ever-increasing annual growth rate.The isotope compositions of dissolved sulfate in the Yangze River range from -3.5‰ to 5.6‰ forδ34 SSO4 and from 3.7‰to 9.2‰forδ18 OSO4 ,showing a significantly negative linear correlation betweenδ34 SSO4 andδ18 OSO4 .The tendency of increasedδ18 OSO4 values from upstream to downstream is controlled byδ18 OH2O values of the Yangtze River water.It is indicated that atmospheric acid deposition and sulfide oxidation are dominant sources of dissolved sulfate in the Yangze River.This study offers theoretical basis which facilitates further environmental explorations for chemical weathering of carbonate and carbon cycling.
Keywords：sulfur isotopeoxygen isotopesulfate sourcethe Yangtze Rivergeochemistry
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 1547-1554,1592 )