Geochemical relationships in CO2-rich therapeutic waters of the Sudetes (Poland)

Geochemical studies of CO2-rich therapeutic waters in the Sudetes have provided new data on a wide range of trace elements, going beyond standard chemical analyses of such waters. A consistent set of physicochemical data obtained using the same analytical methods was subjected to statistical analyses, including hierarchical clustering, factor analysis and nonparametric tests (Kruskal-Wallis, Tau Kendall), to reveal geochemical relationships between physicochemical and chemical parameters in the waters, and their relationships with the aquifer lithology. Distinct differences in the composition of waters found in crystalline rocks (mainly gneisses and mica schists) and sedimentary rocks were identified. The wide range of elements can be associated with the hydrolysis of silicate minerals, including alkali and alkali earth metals (Li, Na, K, Rb, Cs, Be) and (mostly) transition elements (Fe, Mn, Zn, Co, W, Mg). Carbonate equilibria are the next important factor as it determines the aggressiveness of the water towards the minerals of aquifer rocks and affects the concentrations of numerous solutes. The probable common origin of chlorides, bromides and sulphates together with Li, Na, Sr may be related to the relict saline component of deep circulating waters, a hypothesis that requires further investigations.