Hydrochemical evolution of the Na-HCO_3-type groundwater from northern Sikhote-Alin (Far East Russia)

摘要

The Muhen River catchment, located in the northern end of Sikhote-Alin mountain system, is host to Ca-Mg-HCO_3- and Na-HCO_3-type cold CO_2-rich groundwaters issuing from closely spaced wells (～60m intervals). Ca-Mg-HCO_3-type fluids are characterized by low TDS (300-1700 mg/L) and by enriched Fe, Mn, Ba, SiO_2. In contrast, the Na-HCO_3-type fluids have very high TDS (up to 14000 mg/L) and elevated contents of Li, B, Sr, Br and I. This paper demonstrates the origin and evolution of both types of water using detailed descriptions of geological and hydrogeological setting of the area, composition data for major, trace and rare earth elements in the waters, and thermodynamic modeling.