青岛崂山周边地下水化学特征与矿泉水成因分析

HYDROCHEMICAL CHARACTERISTICS OF GROUNDWATER AND GENESIS OF MINERAL WATER AT LAOSHAN MOUNTAIN AND SURROUNDING AREAS, QINGDAO

青岛崂山周边地区构造断裂及花岗岩风化壳发育,具有开发矿泉水的潜力。在崂山周边实施14口水文井,分析区域水文地质特征,发现主要水文地质问题集中在河流中下游人类活动较频繁的地区,工农业污染导致地下水硝酸根等超标,近海区域存在海(咸)水入侵现象。在蓝色硅谷区发现一处矿泉水后备选区,该点位于花岗岩风化壳内,水化学类型为HCO3·SO4-Ca·Na,微量元素锶含量为0.66 mg/L,偏硅酸含量为25.49 mg/L,均高于饮用天然矿泉水最低标准。矿泉水的形成主要与崂山地区地质环境特征及岩石矿物组成等因素密切相关,花岗岩中的二氧化硅和锶在长期水岩作用下融入水中,最终形成偏硅酸-锶复合型矿泉水。

The Laoshan Mountain and its surrounding areas are rich in mineral water under the joint control of structural faults and weathering granite crust. In this paper, 14 hydrogeological wells are selected from the area surrounding the Laoshan Mountain for revealing the hydrogeological characteristics and concerned problems. The main hydrogeological problems are concentrated in the middle and lower reaches of rivers where human activities are frequent and active. Both industrial and agricultural pollution leads to the excess of nitrate in groundwater, in addition to saltwater intrusion occurred in the nearshore areas. A mineral water well located in the weathered crust of granite was discovered this time in the Lanseguigu District. The groundwater in the well belongs to the type of HCO3·SO4-Ca·Na. The contents of strontium(Sr) and metasilicic acid(H2SiO3) of the groundwater are 0.66 and 25.49 mg/L respectively, which are both higher than the standard content for drinking natural mineral water. The formation of the mineral water is closely related to the geological environment of the Laoshan area and mineral compositions of surrounding rocks. The strontium-metasilicic acid mineral water is formed by the dissolution of strontium and silica from granite into water by a long term water-rock interaction. This discovery is significant and may provide a new mineral water producing area in the Laoshan region of Qingdao.