珪酸塩鉱物の水溶液に対する溶解速度 –実験値とフィールド値の比較と流動・溶解カイネティックスモデルによる地下水組成の解釈–

抄録

Simple coupled fluid flow-dissolution kinetics model for one-component and one-dimensional system was applied to estimate the ratio of surface area to mass of water (A/M) for granitic rock (Tsukuba, Japan). Dissolution rate of feldspar experimentally determined was used for the calculation. Estimated A/M values are in a range of 0.1〜6.0. This indicates that the width of fractures in granitic rock penetrated by groundwater is much wider than that of laboratory data. Therefore, it is suggested that the groundwater flow and interaction of groundwater with the country rocks are largely controlled by fractures in the country rocks, A/M and dissolution rate constants of silicates estimated based on field observations previously estimated for a catchment area were incorrect.