Hydrogeochemistry and hydrothermal alteration of the Hanle geothermal field, Djibouti-East Africa

zThis study focuses on the geochemistry and hydrothermal alteration of the Hanle geothermal field (Djibouti-East Africa).Water from five drinking water wells, a hot spring and a steam condensate in the Hanle graben was analyzed for major and minor hydrogeochemical parameters.Analyzed items for water samples (hot spring water, groundwater, and steam condensate) are pH, electric conductivity (EC), SiO2, Cl, SO4, HCO3, F, Na, K, Ca, Mg, Al, Fe, B, As, D, 18 O.Using the chemical compositions and saturation indexes of the hot springs, the reservoir temperature was estimated at around 120 to 125 C.Based on the XRD analysis, the clay minerals smectite, chlorite and illite, as well as quartz, calcite, and alunite, were determined as alteration minerals in this region, which represent high temperature environment (>180 C).The obtained data suggest that the water in the Hanle region was likely formed either by the mixing of groundwater and heated fossil seawater, or by the dissolution of evaporite by heated groundwater.(pH, elektrik iletkenlii (EC)SiO2, Cl, SO4, HCO3, F, Na, K, Ca, Mg, Al, Fe, B, As, D, 18 O).Bu sularn doygunluklar ve eitli jeotermometreler kullanlarak, rezervuar scaklnn yaklak 120-125C olduu tahmin edilmitir.XRD zmlemelerinde yksek scaklk ortamn (>180 C) temsil eden smektit, klorit ve illit tr kil mineralleri ile kuvars, kalsit ve alunit gibi alterasyon mineralleri belirlenmitir.Elde edilen veriler, Hanle blgesindeki suyun ya yeralt Bu almada, Hanle Jeotermal Alannn (Cibuti-Dou Afrika) jeokimyas ve hidrotermal alterasyonuna dayal olarak alann jeotermal potansiyelinin aratrlmas amalanmtr. Hanle grabenindeki be ime suyu kuyusundan, bir kaplcadan ve bir buhar youmasndan alnan sulardan hidrojeokimyasal analizler yaplmtr