河北承德中部富锶地下水与地质建造相关性分析

Correlation analysis between strontium groundwater and geological formation in Chengde central area,Hebei Province

承德中部地区富锶地下水分布较广,本次工作在不同地质建造区采集水样62件,土壤和岩石样品143件,水样中锶含量介于0.11~2.32 mg/L之间,其中锶含量≥0.40 mg/L、达到富锶地下水界限含量的水点共有46个,占全部水点的74.19%。pH为7.16~8.39,属于中性-弱碱性水,水化学类型主要为HCO3-Ca、HCO3·SO4-Ca型,水体中Sr2+与其他主要离子成分相关性较好,均受岩石风化作用控制。碎屑岩建造中地下水Sr2+含量最高,平均值0.75 mg/L,在变质岩建造中地下水Sr^2+含量平均值0.51mg/L,第四系松散堆积物中地下水Sr2+含量平均值0.55 mg/L,火山岩建造中地下水Sr2+含量最低,平均值0.43 mg/L。不同地质建造岩石中的锶含量差异较大,变质岩建造中锶含量最高,平均含量499.94 mg/kg,其次为碎屑岩建造,锶含量平均值为490.77 mg/kg,火山岩建造中锶含量最低,平均值为373.19 mg/kg。地下水中锶元素主要来源于基岩,二者锶含量具有正相关关系,碎屑岩建造及其水体中锶含量均较高,火山岩建造及其水体中含量最低,相比火山岩和变质岩建造,碎屑岩类建造中锶元素更易于向地下水中迁移。

The strontium groundwater is widely distributed in the central area of Chengde.62 water samples were collected in this work.The strontium content is between 0.11 and 2.32 mg/L,of which 46 water points with strontium content≥0.40 mg/L and reac⁃hing the limit content of mineral water,accounting for 74.19%of all water points.pH is between 7.16-8.39,which belongs to neutral weak alkaline water.The main hydrochemical types are HCO3-Ca and HCO3·SO4-Ca the correlation between Sr and other major ion components in water body is good,which is controlled by rock weathering.The Sr2+content of groundwater in clastic rock formation is the highest,with an average of 0.75 mg/L,while that of groundwater in volcanic rock formation is the lowest,with an average of 0.43 mg/L.The strontium content in different geological formations varies greatly,with the highest strontium content in metamorphic rock for⁃mation with an average of 499.94 mg/kg,followed by clastic rock formation with an average of 490.77 mg/kg,and the lowest strontium content in volcanic rock formation with an average of 373.19 mg/kg.Strontium in groundwater mainly comes from bedrock,and there is a positive correlation between the strontium content of the two.The strontium content in clastic rock formations and their groundwater is higher,while the strontium content in volcanic rock formations and their groundwater is the lowest.Compared with volcanic rock and metamorphic rock formations,strontium in clastic rock formations is easier to migrate to groundwater.