Abstract Characterization of geochemistry and geothermometry of the groundwater from the Continental Intercalaire (CI) aquifer, one of the largest aquifers in the world, stretching over one million km2 surface area shared between Algeria, Tunisia and Libya, was conducted in southeastern Algeria nearby the border with Tunisia. Thirty-two water samples were collected from boreholes to analyze the physicochemical parameters and stable isotopes (δ18O(H2O), δ18O(SO4), δ 34S(SO4)) and determine the origin of water mineralization of the CI aquifer. Water temperature was assessed using several geothermometers, such as cations, silica and SO4–H2O stable isotopes. The CI aquifer displayed a discharge temperature varying from 45 to 65.1 °C due to water circulation at deeper depths ranging from 1000 to 2200 m. The Results show that CI water contains high total dissolved solids (TDS) and neutral to slightly alkaline pH. The most frequent water types were Na–Cl–SO4 and Ca–SO4 indicating the geological formation nature of CI aquifer which is mainly composed of evaporites. The application of Na–K and Na–K–Ca geothermometers yielded unreliable temperatures. However, Na–Li geothermometer resulted in relatively plausible temperatures ranging from 74.69 to 147.83 °C. Quartz and CaSO4–H2O isotope geothermometer are the most suitable methods for temperature estimation, due to their attainment of equilibrium resulting in temperatures ranging from 62 to 93 °C, and validation by the multiple mineral equilibrium approach. The present study demonstrated a successful application of CaSO4–H2O isotope geothermometer in a low enthalpy (

中文翻译：

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阿尔及利亚东南部大陆性 Intercalaire 含水层中地下水的地温测量和地球化学：来自阳离子、二氧化硅和 SO4-H2O 同位素地温计的见解

摘要 在阿尔及利亚东南部边界附近，对来自大陆间夹层 (CI) 含水层的地下水进行了地球化学和地球测温表征，该含水层是世界上最大的含水层之一，面积超过 100 万平方公里，由阿尔及利亚、突尼斯和利比亚组成。与突尼斯。从钻孔中采集了32个水样，分析理化参数和稳定同位素（δ18O(H2O)、δ18O(SO4)、δ34S(SO4)），确定CI含水层的水矿化成因。使用几种地温计评估水温，例如阳离子、二氧化硅和 SO4-H2O 稳定同位素。由于水在 1000 至 2200 m 的较深深度循环，CI 含水层的排放温度在 45 至 65.1 °C 之间变化。结果表明 CI 水含有高总溶解固体 (TDS) 和中性至微碱性的 pH 值。最常见的水类型是 Na-Cl-SO4 和 Ca-SO4，表明主要由蒸发岩组成的 CI 含水层的地质形成性质。Na-K 和 Na-K-Ca 地温计的应用产生了不可靠的温度。然而，钠锂地温计得出的温度范围相对合理，范围从 74.69 到 147.83 °C。石英和 CaSO4-H2O 同位素地温计是最合适的温度估计方法，因为它们达到平衡导致温度范围为 62 至 93 °C，并通过多种矿物平衡方法进行验证。本研究证明了 CaSO4-H2O 同位素地温计在低焓下的成功应用（