张掖盆地龙首山山前高氟地下水的形成

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。

High-fluorine Groundwater Formation in Longshoushan Piedmont in Zhangye Basin

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 results 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.