摘要
根据辽东南地区10处泉水、井水的水化学组分和氢、氧同位素组成,讨论了地下水的化学类型、成因及其动态变化特征。测得水样的TDS范围为105.38~809.05 mg·L^(-1),主要阳离子为Na^(+)、Ca^(2+),主要阴离子为SO_(4)^(2-)、HCO_(3)^(-);δ18O和δD值分别为-9.25‰~-7.53‰和-66.43‰~-54.33‰。根据Piper分类法,所采水样可划分为9种水化学类型。样品的氢氧同位素组成表明,研究区泉/井水主要来源于大气降水,并有深部流体的混入。在花岗岩分布区,大气降水经水-岩相互作用演化成F-含量较高的SO_(4)·HCO_(3)^(-)Na型、HCO_(3)^(-)Na型或SO_(4)^(-)Na型水,为花岗岩裂隙水的典型特征;金州的水样因受碳酸盐岩层影响和海水入侵形成Cl-Ca·Mg型水;砂砾岩中的长石类矿物水解和粘土矿物的离子交换作用使得Na+和Ca2+相对富集形成HCO_(3)^(-)Na·Ca型水。地震发生前后部分泉/井出现了K^(+)、F^(-)和Cl^(-)离子浓度的异常变化,这可能是深部流体混入浅层地下水造成的。K^(+)、Mg^(2+)、Ca^(2+)、Cl^(-)离子浓度变化对辽宁地震活动的响应较好。研究结果可用于辽宁地区流体地球化学地震监测、预测和水环境研究。
The chemical types,origins and spatiotemporal variations of groundwater were discussed based on the hydrochemical composition and isotopic ratios of hydrogen and oxygen of the waters from 10 springs and wells in the southeastern Liaoning Province.The measurements demonstrated that the TDS of the water samples ranged from 105.38 mg/L to 809.05 mg/L,with main cations of Na+,Ca^(2+)and main anions of SO_(4)^(-),HCO_(3)^(-),and the values ofδ18O andδD were in the ranges of-9.25‰~-7.53‰and-66.43‰~-54.33‰,respectively.The water samples can be chemically divided into nine types using the Piper classification method.The stable isotopic ratios of H and O indicated that the waters predominantly originated from atmospheric precipitation and small amount of deep fluids.In the area where granite distributed,the atmospheric precipitation became SO_(4)·HCO_(3)^(-)-Na、HCO_(3)^(-)Na or SO_(4)^(-)Na type water with high F-concentration through water-rock interaction,which was the typical feature of granite fissure water.The formation of Cl-Ca·Mg type water in Jinzhou due to the influence of carbonate rocks and seawater intrusion.Due to the hydrolysis of feldspar minerals and the ion exchange of clay minerals,Na+and Ca^(2+)are relatively enriched to form HCO_(3)^(-)Na·Ca type water.The abnormal variations of concentrations of K^(+),Ca^(2+),Mg^(2+)and Cl^(-)occurred before and after the earthquakes,which was most possibly caused by deep fluids mixing with shallow groundwater enriched in Ca^(2+),Mg^(2+),HCO_(3)^(-).The anomalies of K+,Mg^(2+),Ca^(2+),Cl^(-)concentrations are obviously related to seismic activity.The results favor to geochemical monitoring and prediction for earthquake,as well hydro-environment research in this area.
作者
姜莉
崔月菊
王海燕
孙凤霞
王喜龙
杜建国
JIANG Li;CUI Yue-ju;WANG Hai-yan;SUN Feng-xia;WANG Xi-long;DU Jian-guo(Key Laboratory of Earthquake Prediction,Institute of Earthquake Forecasting,CEA,Beijing 100036,China;School of the Earth Science and Resources,China University of Geosciences(Beijing),Beijing 100083,China;Liaoning Earthquake Agency,Shenyang 110000,China)
出处
《地震》
CSCD
北大核心
2021年第3期114-130,共17页
Earthquake
基金
中国地震局地震预测研究所基本科研业务费项目(2018IEF010204)
关键词
地下水
氢氧同位素
地球化学特征
辽东南
Groundwater
Hydrogen and oxygen isotopes
Geochemical characteristics
The southeast Liaoning Province
