高海拔(高山)湖泊是环境过程的有效哨兵,包括当地污染和远距离大气转移,因为这些湖泊极易受到持续的气候变化和不断增加的人为压力的影响。为了提高高山湖泊水柱中微量元素地球化学的知识,我们评估了64个物理化学参数,包括大量和微量营养素,比利牛斯山脉18个湖泊水柱中的主要和微量元素浓度,位于法国和西班牙之间的边界。湖深,形态学,保留时间和分水岭岩石岩性对水柱中的主要和痕量元素浓度没有显着影响。然而,酸性(pH=4.7±0.2)湖泊与中性湖泊(pH=6.8±0.5)明显不同,因为它们的SO42-和痕量金属(Fe,Mn,Zn,Cd,Pb,Co,Ni,Be,Al,Ga和稀土元素)。虽然其中一些元素清楚地标记了流域内富含硫化物的矿物(Fe,Zn,Cd和Pb),成岩元素的流动性增加(Be,Al,酸性湖中的Ga和REE)可能反映了这些元素从源自大气沉积物或周围花岗岩的硅酸盐粉尘中的浸出。同时,与中性湖泊相比,酸性湖水显示较低浓度的溶解含氧阴离子(As,Mo,V,B和W)和升高的SO42-浓度。后者可以导致从水柱中有效地去除Ba。三个湖泊分水岭内金属矿石的开采明显影响了其水柱中观察到的高Zn和Cd浓度,尽管其中两个湖泊不是酸性的。我们得出的结论是,与远距离大气输入相比,局部影响对水柱的影响更大,溶解的微量元素浓度测量可用于揭示湖泊流域内富含硫化物的矿物或酸性矿山排水。
High altitude (alpine) lakes are efficient sentinels of environmental processes, including local pollution and long-range atmospheric transfer, because these lakes are highly vulnerable to ongoing climate changes and increasing anthropogenic pressure. Towards improving the knowledge of trace element geochemistry in the water column of alpine lakes, we assessed 64 physico-chemical parameters, including macro- and micronutrients, major and trace element concentrations in the water column of 18 lakes in the
Pyrenees, located along the border between France and Spain. Lake depth, morphology, retention time and watershed rock lithology did not exhibit sizable impact on major and trace element concentrations in the water column. However, acidic (pH = 4.7 ± 0.2) lakes were distinctly different from circumneutral lakes (pH = 6.8 ± 0.5) as they exhibited >10 times higher concentrations of SO42- and trace metals (Fe, Mn, Zn, Cd, Pb, Co, Ni, Be, Al, Ga and REEs). While some of these elements clearly mark the presence of sulphide-rich minerals within the watershed (Fe, Zn, Cd and Pb), the increased mobility of lithogenic elements (Be, Al, Ga and REEs) in acidic lakes may reflect the leaching of these elements from silicate dust derived from atmospheric deposits or surrounding granites. At the same time, compared to circumneutral lakes, acidic lake water displayed lower concentrations of dissolved oxyanions (As, Mo, V, B and W) and elevated SO42- concentrations. The latter could lead to efficient Ba removal from the water column. The exploitation of metal ores within the watershed of three lakes clearly impacted high Zn and Cd concentrations observed in their water column, despite two of these lakes not being acidic. We conclude that local impacts have a greater effect on the water column than long-range atmospheric inputs and that dissolved trace element concentration measurements can be used for revealing sulphide-rich minerals or acid mine drainage within the lakes\' watershed.