Mineralization of freshwater-dissolved gases, such as CO₂ and H₂S, in subsurface mafic rocks is a successful permanent gas storage strategy. To apply this approach globally, the composition of locally available water must be considered. In this study, reaction path models were run to estimate the rate and extent of gas mineralization reactions during gas-charged freshwater and seawater injection into basalts at temperatures of 260, 170, 100, and 25°C. The calculations were validated by comparison to field observations of gas-charged freshwater injections at the CarbFix2 site (Iceland). The results show that more than 80% of the injected CO₂ dissolved in freshwater or seawater mineralizes as Ca and Fe carbonates at temperatures ≤170°C after reaction of 0.2 mol/kgw of basalt, whereas at 260°C much lower carbon mineralization rates are observed in response to the same amount of basalt dissolution. This difference is due to the competition between carbonate versus non-carbonate secondary minerals such as epidote, prehnite, and anhydrite for Ca. In contrast, from 80 to 100% of the injected H₂S is predicted to be mineralized as pyrite in all fluid systems at all considered temperatures. Further calculations with fluids having higher CO₂ contents (equilibrated with 9 bar pCO₂) reveal that i) the pH of gas-charged seawater at temperatures ≤170°C is buffered at ≤6 due to the precipitation of Mg-rich aluminosilicates, which delays CO₂ carbonation; and ii) the most efficient carbonation in seawater systems occurs at temperatures <150°C as anhydrite formation is likely significant at higher temperatures.

地下镁铁质岩石中诸如CO ₂和H ₂ S之类的淡水溶解气体的矿化是一种成功的永久性储气策略。为了在全球范围内采用这种方法，必须考虑当地可用水的成分。在这项研究中，运行了反应路径模型以估计在260、170、100和25°C的温度下充气的淡水和海水注入玄武岩中的气体矿化反应的速率和程度。通过与在CarbFix2站点（冰岛）充气的淡水注入的现场观测结果进行比较，对计算结果进行了验证。结果表明，超过80％的注入的CO ₂在0.2 mol / kgw的玄武岩反应后，在≤170°C的温度下，溶解在淡水或海水中的碳酸钙和铁的碳酸盐会矿化，而在260°C时，由于同样数量的玄武岩溶解，观察到的碳矿化速率要低得多。这种差异是由于碳酸盐与非碳酸盐次生矿物（如附子，钙钛矿和硬石膏）之间对Ca的竞争所致。相反，在所有考虑的温度下，预计所有流体系统中80％至100％的注入H ₂ S会矿化为黄铁矿。具有更高CO ₂含量的流体的进一步计算（与9 bar p CO ₂平衡））揭示：i）由于富含Mg的铝硅酸盐的沉淀而延迟了CO _2的碳化，在≤170°C的温度下充气的海水的pH缓冲在≤6 。ii）海水系统中最有效的碳酸化发生在<150°C的温度下，因为在较高的温度下硬石膏的形成可能很明显。