Chemistry of waters from selected caves in Slovakia—a reconnaissance study

The chemical composition of water samples was studied from different caves in Slovakia. The water samples were collected from caves of two karst regions: (1) the Demänovský Cave System (DCS), situated in the Low Tatra Mountains (Northern Slovakia), which is mainly formed of limestone and dolomites; and (2) the Slovakian Karst to the Southeast is formed of limestone. A considerable difference between water from the two regions was shown. The waters from the DCS, that were controlled by vadose water percolating through different types of host rocks, contained more Mg ions than those from the Slovakian Karst caves whereas, the concentration of SO₄ was controlled by the dissolution of displacive gypsum and/or oxidation of pyrite. The distribution of NO₃ in the studied samples was random, hence nitrates probably derived from few pollution sources. The total mineralization of the water was covariant with calcite and aragonite saturation indices. In general, both parameters are higher in the Slovakian Karst caves than in the DCS. It is controlled probably by differences in climatic conditions, soil and plant covers between these two regions. The main goal of this article is to characterize the major-ion water chemistry within the studied caves as well as some microelements. The results have confirmed the dominant role of the bedrock petrography in forming the general chemistry of cave waters.