Chemical denudation dynamic based on hydrochemical measurements in the area of Drienovecká jaskyňa Cave basin (Slovak karst, Slovakia)

Abstract

Denudation is a fundamental process for the development of karst relief. It has different intensity in different geological and climatic condition and beside this many other partial factors influence the intensity and dynamic of the process during the year. In karst systems, there is often a positive correlation between water partial pressure of CO2 and denudation. The Drienovecká jaskyňa Cave spring represents typical active fluviokarstic spring and its catchment area is represented by Wetterstein and Waxenec limestones, and Drienovec conglomerates. This catchment study area is located at the contact of the conti-nental and oceanic climate, in terms of altitude at the border between the lowland and moun-tain climate. During three hydrological years we measured main karst water parameters that helped us bring first results on chemical denudation in the catchment area. The water from the spring is of calcium-magnesium-bicarbonate type. Hydrogeochemical analyses in-dicate that it is mostly water from an open hydrogeological structure. Water of the cave spring is oversaturated with respect to calcite, which is documented by the saturation index of calcite, whose values are higher than the solubility product of calcite. During the studied period, the dynamic of the chemical denudation rate is clearly observable with peaks in spring months in year 2014 and 2016. The average value of denudation rate for the entire period is 21.06 mg Ca2+. Factors that influence chemical denudation include, for example, type of carbonate rock, CO2 partial pressure, water and air temperature, chemical compo-sition of the aqueous solution, activity of soil organisms, vegetation and others. Water from melted snow can also play a significant role in changes in water chemistry and thus chemical denudation. URL: https://www.gcass.science.upjs.sk/