Groundwater-rock interaction in Hakushu area, Yamanashi Prefecture and a role of host rocks for CO₂ underground sequestration

Abstract

Chemical and mineralogical compositions of groundwater and country rocks in sedimentary an d granitic rock areas in Hakushu area, Yamanashi Prefecture are distinctly different. Anion (Cl^-, SO₄^2-) concentrations in the sedimentary rock area are higher than those in the granitic rock area due to the influence of fossil seawater, but cation concentrations are not different and pH is higher. Saturation index for calcite in groundwater in the sedimentary rock area is higher than that in the granific rock area, suggesting groundwater chemistry of the sedimentary rock area is influenced by the dissolution of calcite.