LAUSR

Abstract Interactions between meteoric water and ultramafic rocks in the Oman Ophiolite generate waters of variable physicochemical characteristics. The discharge of these waters forms complex alkaline pool networks, in which mineral precipitation is triggered by mixing, evaporation, and uptake of atmospheric CO2. A systematic and co-localized sampling of waters and solids in two individual spring sites allowed us to determine the saturation state of a range of minerals and correlate them to the different water and precipitate types. We subdivided the waters of the spring sites into three distinctive types: i) Mg-type; moderately alkaline (7.9 11.6), Ca2+–OH−-rich waters, and iii) Mix-type; alkaline to hyperalkaline (9.6