TY - JOUR
T1 - Hydrogeochemical and isotope geochemical study of northwestern Algerian thermal waters
AU - Belhai, Mohamed
AU - Fujimitsu, Yasuhiro
AU - Bouchareb-Haouchine, Fatima Zohra
AU - Iwanaga, Tatsuto
AU - Noto, Masami
AU - Nishijima, Jun
N1 - Funding Information:
We would like to express our sincere thankful acknowledgement for the Ministry of Education, Culture, Sports, Science and Technology (MEXT, Japan) Ph.D. scholarship support providing the first author during this study. We would also like to show our sincere gratitude and acknowledgement to the G-COE of Kyushu University for funding of this research.
Publisher Copyright:
© 2016, Saudi Society for Geosciences.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Northwestern Algeria is characterized by a large number of thermal waters and volcanic eruptions and belongs to the Alpine-Magrebide belt. The geothermal reservoirs that feed these reservoirs are mainly hosted by a fractured Jurassic limestone and dolomite sequence. Seven samples were collected from thermal springs of near-neutral pH (6.2 to 7.56) with discharge temperatures between 42.9 and 66.1 °C. Hydrogeochemical analyses of the thermal waters reveal four types (Na+-Ca2+-Cl−, Na+-Ca2+-Cl−-HCO3 −, Na+-Ca2+-Cl−-SO4 2−, and Na+-HCO3 −-Cl−) and show high total dissolved solids up to 4002 mg/L. Stable isotopic results (δ18 O and δ D) indicate that the thermal waters are of meteoric origin deeply infiltrated and heated by advective heat anomalies and raised up to the surface through deep-seated faults acting as hydrothermal conduits. The estimated reservoir temperatures using silica geothermometers and fluid-mineral equilibria overlap between 66 and 125 °C, while Na/K and K/Mg geothermometers give much higher and lower results, respectively, and are mainly influenced by mixing with cooler Mg groundwaters as indicated by the Na-K-Mg plot in the immature water field and in silica and chloride mixing models. Thermal waters deeply circulated and heated at a depth of 2 km were supplied by the higher geothermal gradients, which can reach 42.8 °C km−1 due to the complex geological setting.
AB - Northwestern Algeria is characterized by a large number of thermal waters and volcanic eruptions and belongs to the Alpine-Magrebide belt. The geothermal reservoirs that feed these reservoirs are mainly hosted by a fractured Jurassic limestone and dolomite sequence. Seven samples were collected from thermal springs of near-neutral pH (6.2 to 7.56) with discharge temperatures between 42.9 and 66.1 °C. Hydrogeochemical analyses of the thermal waters reveal four types (Na+-Ca2+-Cl−, Na+-Ca2+-Cl−-HCO3 −, Na+-Ca2+-Cl−-SO4 2−, and Na+-HCO3 −-Cl−) and show high total dissolved solids up to 4002 mg/L. Stable isotopic results (δ18 O and δ D) indicate that the thermal waters are of meteoric origin deeply infiltrated and heated by advective heat anomalies and raised up to the surface through deep-seated faults acting as hydrothermal conduits. The estimated reservoir temperatures using silica geothermometers and fluid-mineral equilibria overlap between 66 and 125 °C, while Na/K and K/Mg geothermometers give much higher and lower results, respectively, and are mainly influenced by mixing with cooler Mg groundwaters as indicated by the Na-K-Mg plot in the immature water field and in silica and chloride mixing models. Thermal waters deeply circulated and heated at a depth of 2 km were supplied by the higher geothermal gradients, which can reach 42.8 °C km−1 due to the complex geological setting.
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U2 - 10.1007/s12517-015-2252-2
DO - 10.1007/s12517-015-2252-2
M3 - Article
AN - SCOPUS:84959373932
SN - 1866-7511
VL - 9
SP - 1
EP - 17
JO - Arabian Journal of Geosciences
JF - Arabian Journal of Geosciences
IS - 3
M1 - 169
ER -