Hydrogeochemical patterns of deep thermal groundwater in South Korea

Abstract

The results of our study show that deep thermal groundwater in Korea is clustered into three major types. These are 1) alkaline water with high pH, 2) CO2-rich acidic water, and 3) saline water with high TDS. Among them, the first type is predominant and occurs preferentially in granitic rocks. The relationships between physicochemical variables illustrate that hydrochemistry of each groundwater type is mainly evolved through distinct paths of water-rock interaction but is modified by varying degree of mixing with dilute shallow groundwater during ascent.