Equilibrium of nitrogen-rich spring waters of the Baikal Rift Zone with host rock minerals as a basis for determining mechanisms of their formation

This paper presents calculations of equilibria between nitrogenrich hot springs of the Baikal Rift Zone (BRZ) and a secondary mineral assemblage (carbonate, fluoride, clay, zeolite, and other minerals). The results confirm the equilibrium–nonequilibrium character of the nitrogen spring water–rock system. Unlike other water types, the system evolves under conditions of continuous incorporation of chemical elements released from the host minerals into the newly formed secondary minerals. This allows the system to remain dynamically stable with no increase in salinity, despite continued water–rock interaction. The main factor responsible for this state of the system is a deficiency of acids, i.e., high pH. As a result, the disturbance of relationships between concentrations of aqueous species compared to the starting composition of dissolved solids produces a deficiency of some elements (Ca, Mg, Fe, Al, etc.) and an excess of other elements (Na, Si, F, etc.).