Hydrogeochemical and isotopic characteristics of groundwater in Mbanga, Njombe and Penja (Banana Plain) - Cameroon

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• 作者：Andrew Ako Ako ; Jun Shimada ; Takahiro Hosono ; Kimpei Ichiyanagi ; George Elambo Nkeng ; Gloria Eneke Takem Eyong ; Ntankouo Njila Roger
• 关键词：Hydrogeochemistry ; Environmental isotopes ; Groundwater ; Mbanga ; Njombe ; Penja ; Cameroon
• 刊名：Journal of African Earth Sciences
• 出版年：2012
• 出版时间：18 October, 2012
• 年：2012
• 卷：75
• 期：Complete
• 页码：25-36
• 全文大小：2779 K

文摘

Hydrochemical and environmental isotopic (²H, ¹⁸O and ³H) data were used to investigate the hydrogeochemical and isotopic characteristics of groundwater within Mbanga, Njombe and Penja (Banana Plain). Hydrogeochemically, the groundwaters are mainly Ca-HCO₃, Ca-Mg-HCO₃, Ca-Na-HCO₃, and Ca-Na-NO₃-Cl-HCO₃ water types. The groundwater chemistry may be adequately explained by the incongruent dissolution of silicate and alumino-silicate minerals, impact of anthropogenic activities and cation exchange between the groundwaters and clay minerals. The isotopic contents of groundwaters ranged from ?4.2¡ë to ?2.1¡ë for ¦Ä¹⁸O, from ?23.4¡ë to ?10.6¡ë for ¦ÄD and from 0.6 to 1.4 TU for tritium. In the conventional ¦ÄD-¦Ä¹⁸O diagram, the distribution of data points indicates that the groundwaters are of meteoric origin and have not been affected by evaporation. Environmental isotopes (¹⁸O, ²H and ³H) indicate mixing between recent and old groundwaters; the latter were recharged under more humid climatic conditions than that at present or from higher elevations. Groundwater in Mbanga, Njombe and Penja are of meteoric origin, young and are still in the early stage of geochemical evolution.