Geochemical Patterns of Mud Volcanic Waters: Reviewed Worldwide Data

— This paper is the world’s first to generalize and analyze worldwide data on the chemical composition of waters from 175 onshore mud volcanoes. Empirical probability density functions are obtained for the dominant anions and cations, whose average concentrations (Clarke values) were also estimated. Correlations between the geochemical parameters of the samples (Na and Cl concentrations, Na/Cl ratio and HCO_3^ - concentration, Cl/Br ratio and Cl concentration, Cl/B ratio and HCO_3^ - concentration, etc.) were determined and used in the further analysis of conditions under which mud volcanic waters are formed. The waters are mainly slightly alkaline, with mineralization (TDS) in the range of 5 to 25 g/L and mostly belong to the Cl–Na type (about 58