张掖盆地龙首山山前高氟地下水的形成

摘要

Fluorine is one of essential elements of the human body,but excessive F can be harmful to human body.The formation mechanism of high fluorine groundwater has been a hot topic of hydrogeochemical research.The authors analyzed numerous groundwater level and quality data from 1:50,000 hydrogeological survey in Zhangye Basin.By using hydrogeochemical and oxygen deuterium isotope methods,the authors discussed the formation mechanism of high-fluorine groundwater in Longshoushan piedmont in a high accuracy level.The resuits show that high-fluorine groundwater mainly origins from Longshoushan mountain fluorine-bearing rock.The high-fluorine surface water in Longshoushan mountain recharge into Quaternary aquifer in Zhangye Basin through seasonal floods and mixes with low-fluorine groundwater from upstream.Different recharge sources divided groundwater into three strips in Longshoushan piedmont.%氟是人体的必须元素之一,饮水中氟元素过量会导致地氟病.高氟地下水的形成机制一直是水文地球化学研究的一个热门话题.利用在张掖盆地开展1:5万水文地质调查所获得的大量水位、水质资料,运用水化学和氘氧同位素方法,在较高精度水平上探讨了龙首山前高氟地下水的形成机制.研究结果表明,龙首山前地下水中的F-主要来源于龙首山含氟岩石,通过季节性洪水的方式补给到盆地的第四系含水层中,并与盆地上游来源的低氟地下水发生混合,使龙首山前地下水分为三个条带.