The genesis of groundwater composition in deep basin structures on the example of the Bohemian Cretaceous Basin and the Eger Rift relationship

This thesis deals with genesis of the Cretaceous thermal waters in the Ústí nad Labem. These thermal waters are interesting in that are very different from other Cretaceous thermal waters, which also appear in Benešov-Ústí aquifer system of the Bohemian Cretaceous Basin in Děčín. Thermal waters in the Ústí nad Labem area more than chalk waters resemble the thermal waters in Teplice, which are associated with body of Teplice rhyolite. Many authors studied thermal waters in the Ústí nad Labem, but isotope analysis and inverse geochemical modeling were not used for their study. Results based on water chemistry, water D and 18 O, 87 Sr/86 Sr ratios, and dissolved sulfate 34 S and 18 O values, indicate mixing of ground water from aquifers of the Bohemian Cretaceous Basin with ground water derived from crystalline rocks of the Erzgebirge Mts. Unlike thermal waters in Děčín are Ca-HCO3 type (160 mg/L), in Ústí nad Labem there are two types of thermal waters, Na-HCO3 type with higher TDS values (over 1 g/L) and Na-(Ca)-HCO3-SO4 type with lower TDS values (approximately 600 mg/L). Carbon isotope data and speciation and inverse geochemical modeling suggest a significant input of endogenous CO2 at Ústí nad Labem. Besides CO2 input, both silicate dissolution and cation exchange coupled with dissolution of..