Much of the water sources along the East Africa Rift System (EARS) are characterized by high fluoride. Geochemical evaluation of volcanic materials was undertaken to assess the possible source of high fluoride concentration, its mobility and eventual contamination of groundwater systems. In addition to rocks, this assessment involved evaluation of soils and water samples to elucidate the fluoride concentration in a rock-soil-water system. Results indicated that volcanic rocks are weakly to moderately fractionated with variable compositions that span from foidite to andesite. Petrographic examination indicated the presence of at least four minerals that are known to incorporate fluorine (F) in their lattice structures. In order of decreasing abundance, these minerals include: sphene or titanite, hornblende, apatite and biotite. These results indicated that fluorine occurs in all rock types in varying amount that ranges from 251 to 19,122 mg/kg (mean = 3921 mg/kg, n = 68) and that andesitic rocks contain the highest amount than the other rock types (mean = 7133 mg/kg, n = 13). This may suggest that F is largely incorporated during late crystallization process. Based on rocks and equivalent soils, fluorine was higher in rocks than equivalent soils at the ratio of 3:1. In general, distribution of F is largely controlled by parent material, the texture of the parent material and geomorphology. Furthermore, it is revealed that the amount of fluoride in well waters correlated well with fluorine in the rocks and/or soils proximal to the wells.

东非裂谷系统 (EARS) 沿线的大部分水源都含有高氟化物。对火山物质进行了地球化学评估，以评估高氟化物浓度的可能来源、其流动性和地下水系统的最终污染。除了岩石外，该评估还包括对土壤和水样的评估，以阐明岩石-土壤-水系统中的氟化物浓度。结果表明，火山岩是弱到中度分馏的，其成分可变，从 foidite 到安山岩。岩相学检查表明至少存在四种已知在其晶格结构中掺入氟 (F) 的矿物。按照丰度递减的顺序，这些矿物包括：钆或钛石、角闪石、磷灰石和黑云母。这些结果表明，氟在所有岩石类型中的含量各不相同，范围从 251 到 19,122 mg/kg（平均值 = 3921 mg/kg，n = 68），并且安山岩的含量高于其他岩石类型（平均值 = 7133 毫克/公斤，n = 13)。这可能表明 F 在后期结晶过程中大量掺入。以岩石和等效土壤为基础，以3:1的比例计算，岩石中氟含量高于等效土壤。通常，F 的分布主要受母材、母材的质地和地貌控制。此外，据揭示，井水中的氟含量与井附近岩石和/或土壤中的氟含量密切相关。n = 68）并且安山岩的含量高于其他岩石类型（平均值 = 7133 mg/kg，n = 13）。这可能表明 F 在后期结晶过程中大量掺入。以岩石和等效土壤为基础，以3:1的比例计算，岩石中氟含量高于等效土壤。通常，F 的分布主要受母材、母材的质地和地貌控制。此外，据揭示，井水中的氟含量与井附近岩石和/或土壤中的氟含量密切相关。n = 68）并且安山岩的含量高于其他岩石类型（平均值 = 7133 mg/kg，n = 13）。这可能表明 F 在后期结晶过程中大量掺入。以岩石和等效土壤为基础，以3:1的比例计算，岩石中氟含量高于等效土壤。通常，F 的分布主要受母材、母材的质地和地貌控制。此外，据揭示，井水中的氟含量与井附近岩石和/或土壤中的氟含量密切相关。在 3:1 的比例下，岩石中的氟含量高于同等土壤。通常，F 的分布主要受母材、母材的质地和地貌控制。此外，据揭示，井水中的氟含量与井附近岩石和/或土壤中的氟含量密切相关。在 3:1 的比例下，岩石中的氟含量高于同等土壤。通常，F 的分布主要受母材、母材的质地和地貌控制。此外，据揭示，井水中的氟含量与井附近岩石和/或土壤中的氟含量密切相关。