摘要
冀北坝上一带玄武岩地区广布富偏硅酸地下水,研究其形成机制及其水岩作用过程对矿泉水的合理开发利用与京津冀水源涵养功能具有重要意义.结合玄武岩地质建造地下水赋存特征,综合利用水化学分析,玄武岩岩石风化机制,水岩相互作用矿物平衡体系,δD、δ18O和δ13C同位素、14C放射性同位素测年等方法,剖析了汉诺坝玄武岩偏硅酸矿泉水形成的岩石地球化学风化和水文地球化学过程及地质建造制约因素.结果表明,研究区矿泉水为低矿化度的HCO3-Ca·Mg型与HCO3-Na·Ca型水,矿泉水形成类型有构造断裂深循环淋溶型和层状补给富集埋藏型2类.上层古风化壳地下水14C校正年龄约为4050 a,地下水可溶性无机碳来源于土壤CO2与幔源CO2的混合作用.偏硅酸矿泉水的形成与分布受玄武岩地质建造制约,受岩石地球化学特征、岩石风化地表过程和水文地球化学响应过程控制.地下水中偏硅酸主要来源于玄武岩中斜长石、单斜辉石、镁橄榄石等硅酸盐矿物的风化水解;岩石矿物风化的水化学响应过程受溶滤作用控制,受阳离子交换作用影响.
Metasilicate mineral groundwater is widely distributed in basaltic area of Bashang area in North Hebei Province.It is of great significance to ascertain the formation mechanism and water-rock interaction process for the rational development and utilization of mineral water and the water conservation function of Beijing-Tianjin-Hebei region.Hydrochemical components statistical analysis,chemical weathering process of basaltic,mineral equilibrium phase of water-rock interaction process,δD,δ18 O,δ13 C isotopes and radioisotope dating by14 C were used to identify the geological construction constraints and ascertain the formation mechanism of metasilicate mineral groundwater.The results show that the mineral groundwater of study area is characterized by low mineralization while the main hydrochemical types of groundwater are HCO3-Ca·Mg and HCO3-Na·Ca.The outcropping mechanism of mineral water can be divided into two types:deep cyclic leaching of tectonic faults and stratified enrichment of recharge type.The age of groundwater in the upper paleoweathering crust is about 4050 a,and the dissolved inorganic carbon of groundwater comes from the mixing of soil CO2 and mantle CO2.Metasilicic acid in groundwater originates from the weathering and hydrolysis of plagioclase,pyroxene and forsterite in basaltic.Hydrogeochemical response of rock weathering is controlled by rock mineral leaching and affected by hydrochemical parameters cation exchange.The formation and distribution of metasilicate mineral water are restricted by the basalt geological construction,and controlled by weathering mechanism of rocks and hydrogeochemical conditions.
作者
孙厚云
卫晓锋
孙晓明
贾凤超
李多杰
何泽新
李健
Sun Houyun;Wei Xiaofeng;Sun Xiaoming;Jia Fengchao;Li Duojie;He Zexin;Li Jian(School of Water Resources and Environment,China University of Geosciences,Beijing 100083,China;Beijing Institute of Geology for Mineral Resources,Beijing 100012,China;Tianjin Center,China Geological Survey,Tianjin 300170,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2020年第11期4236-4253,共18页
Earth Science
基金
中国地质调查局项目(Nos.DD20160229-01,DD20190822)。
关键词
偏硅酸矿泉水
玄武岩
水化学
风化机制
地质建造
御道口
地球化学
metasilicate mineral water
basalt
hydrogeochemistry
weathering mechanism
geological construction
Yudaokou
geochemistry
