Formation of Nitrogen-Rich Hot Springs in the Water–Granite and Water–Porphyrite Systems

Abstract

The processes of evolutionary transformation of solutions in crystalline rocks of different composition under formation parameters of nitrogen-bearing hot springs have been studied using physicochemical modeling. It has been established that the fundamental factor in the formation of solutions that correspond to modern nitrogen hot springs in composition is the presence of elements that produce anions in the host rocks in appropriate concentrations. They create a characteristic geochemical environment that controls their concentrations and speciation in the solutions and the crystallization/dissolution timing and amounts of secondary minerals at each step of changing the value of the rock/water ratio. Both cations and anions clearly maintain the sequence of their presence in the solution in accordance to their concentration in the rock until the time when the crystallization of secondary minerals modifies the trends of component concentrations in the solution. The reasons for low and very low mineralization of nitrogen hot springs, low concentrations of Mg, Ca, and K and high contents of Na and Si are elucidated. Modern nitrogen terms cannot be formed in rocks containing elements that form anions in an amount corresponding to their average values. Based on the revealed high discreteness of the distribution of these elements in space and their extremely poor understanding, it is concluded that the successful study of hydrogeochemical processes is impossible without taking into account the geological heterogeneity, which is a key problem of hydrogeochemistry and is not taken into account when the processes of interaction in the water/rock system are studied.