云南白水台泉水地球化学特征及其气候环境指示意义  

Geochemical characteristics of spring water in Baishuitai of Yunnan and their indicative significance on climatic environment

作　　者：赵茜[1] 徐洪阳 甘海伶 叶爱华 周立旻[1] 郑祥民[1] ZHAO Xi;XU Hongyang;GAN Hailing;YE Aihua;ZHOU Limin;ZHENG Xiangmin(Key Laboratory of Geographic Information Science,Ministry of Education,School of Geographic Sciences,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学地理科学学院地理信息科学教育部重点实验室,上海200241

出　　处：《中国岩溶》2024年第3期538-551,共14页Carsologica Sinica

基　　金：国家自然科学基金面上项目(41871015);国家自然科学基金面上项目(41971020)。

摘　　要：为研究岩溶地下水的水文地球化学演化特征,对云南白水台地区雨水和泉水中氢氧稳定同位素(δD、δ^(18)O)组成和微量元素含量进行了为期近5年(2018年1月至2022年10月)以月为频率的连续监测。结果表明:(1)白水台雨水中δD、δ^(18)O具有明显的季节性变化特征,均表现为雨季偏轻,旱季偏重,主要受到水汽来源与蒸发条件的影响;(2)白水台泉水受当地大气降水补给,其δD、δ^(18)O经历了石灰岩基层中不同通道、裂隙网络中的新、老水混合导致的同位素调蓄平滑作用以及与深部来源CO_(2)的氧同位素交换作用,修正性继承了雨水中δD、δ^(18)O的部分特征;(3)泉水中Ca、Mg、Sr、Ba、Si等元素主要来源于喀斯特水体侵蚀下围岩的溶解,其含量变化可能指示了降水量的变化;而Fe、Al、Mn等元素主要来源于大气降水对上覆土壤的淋滤作用,其浓度变化可能反映了降水强度的变化。Understanding the geochemical characteristics and dynamic changes of groundwater(e.g.,springs,etc.)is an important scientific reference for accurately interpreting the paleoclimatic and environmental information on karst deposits(e.g.,stalagmites,travertine,etc.).In this study,we continuously collected local rainwater samples and S3 spring water in Baishuitai area of Yunnan Province on a monthly frequency for nearly 5 years(January 2018 to October 2022).We analyzed the temporal variations of stable isotopes of hydrogen and oxygen(δD andδ^(18)O)compositions and trace element contents in the two types of water bodies to identify the recharge source and hydrogeochemical evolution process of Baishuitai spring water,and to reveal the source differences of trace elements in spring water and their indicative significance on climate and environment.The results showed as follows.(1)Values of stable isotope composition of rainwater in Baishuitai region of Yunnan had obvious seasonal variation characteristics-high in the dry season and low in the rainy season.This result was mainly affected by water vapor source and evaporation conditions.During the dry season,water vapor mainly came from the stable continental air mass,and the evaporation effect was strong,which resulted in the enrichment of D and 18O in the remaining water vapor mass.During the rainy season,multiple fractionation and condensation processes occurred when water vapor migrated from the sea to the land,due to the influence of the southwest monsoon and the southeast monsoon.D and 18O were severely scoured,thus makingδD andδ^(18)O light in rain during the precipitation process.(2)The stable isotopic compositions of hydrogen and oxygen in Baishuitai spring water were on or near the atmospheric precipitation line,indicating that the spring water was mainly supplied by atmospheric precipitation.During the infiltration of atmospheric precipitation into the zone of shallow circulation runoff,new and old water from different channels and fissure networks was cont

关 键 词：氢氧稳定同位素 微量元素 泉水 钙华 云南白水台 

分 类 号：P641.3[天文地球—地质矿产勘探]