中国岩溶2013，Vol.32Issue(2)：123-132,10.
重庆地区岩溶地下河水溶解无机碳及其稳定同位素特征
Dissolved inorganic carbon and stable carbon isotope in karst subterranean streams in Chongqing, China
摘要
Abstract
Stable carbon isotope is a useful and powerful tool for tracing the origin and transformation of carbon in karst dynamics system.For obtaining the characteristics of hydrochemistry and isotope,groundwater samples in wet and dry seasons from 63 karst subterranean streams in Chongqing are collected in this study.The results show that the HCO3 is the dominant species of the DIC in ground waters and the concentration of HCO3 is lower in wet season than dry season due to dilution.δ13C-DIC (V-PDB) in karst subterranean streams in Chongqing varies from-15.34 ‰～-5.89 ‰ in dry season and from-17.40 ‰～-4.23 ‰ in wet season.The widely variations of δ13C in wet season show the complex origins of carbon in karst subterranean streams in wet season.Based on the δ13C isotope mass balance equation,the amount of DIC that comes from the carbonate rock dissolution is calculated in this study.The calculated results show that 45.1 ％～79.7 ％of the DIC in the dry season and 34.6 ％～82.1％ in the wet season is from dissolution of carbonate rocks in karst groundwater.The calculated results also shows that the DIC and the corresponding δ13C proportion originated from the carbonate rock dissolution is not necessarily 50 ％ according to the molar ration of karst chemical reaction equation,but has a changes range at some extend.As a result,this study suggests that we should deduct first the DIC originated from the carbonate rock dissolution using the δ13C when we calculate the carbon sink of karst processes,and then calculate further the karst carbon sink.关键词
溶解无机碳/碳同位素/岩溶地下河/重庆Key words
dissolved inorganic carbon/ stable carbon isotope/ karst subterranean steam/ Chongqing municipality分类
天文与地球科学引用本文复制引用
蒲俊兵..重庆地区岩溶地下河水溶解无机碳及其稳定同位素特征[J].中国岩溶,2013,32(2):123-132,10.基金项目
国家自然科学基金(41202185)、国土资源部公益性行业科研专项(201311148)、广西自然科学基金项目(2012GXNSFBA053137)、中国地质调查局地质调查项目(12120113006700)和IGCP/SIDA598项目 （41202185）
