Abstract The geochemical composition of waters from wells fed by Taftan aquifer located east of Taftan volcano, mainly focusing on the distribution of arsenic, was investigated in order to provide insights into the geochemical processes controlling the chemistry of the shallow aquifer and the possible influence of hydrothermal fluids from the volcano on groundwater quality. For this purpose, 16 water samples were collected and analyzed for the determination of selected trace elements, major ions and stable isotopes (18O and 2H). The chemical and isotopic features of the investigated groundwater samples suggest that they are significantly affected by fluids originated from Taftan volcano driven toward the surface by local and regional fault systems. The volcanic source is also responsible for the relatively high concentrations of As, U and V, which pose severe concerns for the quality of the water resource in the area. Distribution of As seems to be independent of pH values and the concentrations of Fe, the latter commonly forming As-adsorbing minerals, likely due to the precipitation of siderite and the occurrence of As colloids. Lack of correlation between As and SO4 seems to exclude a significant As contribution from sulfide minerals.

中文翻译：

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伊朗东南部塔夫坦火山以东 Tahlab 含水层的水文地球化学、环流路径和砷分布

摘要 研究了塔夫坦火山东部塔夫坦含水层井水的地球化学组成，主要集中在砷的分布上，以了解控制浅层含水层化学的地球化学过程和热液可能的影响。来自火山的流体对地下水质量的影响。为此，收集并分析了 16 个水样，以确定选定的痕量元素、主要离子和稳定同位素（18O 和 2H）。研究的地下水样品的化学和同位素特征表明，它们受到源自塔夫坦火山的流体的显着影响，这些流体被局部和区域断层系统推向地表。火山源也是造成 As、U 和 V 浓度相对较高的原因，这对当地水资源的质量构成了严重的担忧。As 的分布似乎与 pH 值和 Fe 的浓度无关，后者通常形成吸附 As 的矿物，这可能是由于菱铁矿的沉淀和 As 胶体的出现。As 和 SO4 之间缺乏相关性似乎排除了硫化矿物的显着 As 贡献。