Oxygen Isotope Composition Snapshot of Spring Waters in a Karstified Plateau

Indicative mean transit time estimation from δ18O values as groundwater vulnerability indicator in karst-fissure aquifers

“…The median value was -9.48 %, the arithmetical mean was -9.41 %, and standard deviation value of the whole set was -0.74 %. In spite of short sampling period (12 days) and very similar hydrogeological settings of all sampled groundwater sources, very scattered d 18 O values were detected (Malík et al 2014). Although only freshwater of apparently similar origin was sampled, such a range of values cannot be explained by simple impact of altitudinal effect.…”

“…1), all natural groundwater outlets had to be identified, visited and documented on the maps at a scale of 1:10,000. Muránska planina (with its centre of approximately E20°00 0 Lon N48°45 0 Lat) is a karstic plateau built mainly by karstified Middle and Upper Triassic limestones and dolomites belonging at least to two different tectonic units overthrusted one over other, thus forming a complicated geological structure (Š vasta et al 2004;Malík et al 2014). In spite of its complexity, the presence of carbonate rocks in all mentioned units allowed the creating of one relatively uniform, hydrogeologically interconnected karstified body.…”

“…Approximately keeping the regional altitudinal trend but in wide span of values, it seems that differences in d 18 O were caused more by other factors than altitudinal effect, very probably by differences in individual groundwater circulation patterns (Malík et al 2014). If the precipitation input is variable in time, we can possibly follow this signal after its transfer through the aquifer, in groundwater at springs (Maloszewski et al 1983;McGuire and McDonnell 2006).…”

“…3). Precipitation data directly measured within the area (precipitation in Tisovec; snow samples from the top of the Plateau; Malík et al 2014) during the next winter and spring of 2003 were in accordance with the records of the three previously mentioned GNIP station (Fig. 3).…”

“…Taking these into account, the d 18 O values in groundwater sources of the Muránska planina Plateau should be ranging within an approximate width of interval from 1.0 to 2.1 %, and not 3.58 % as were measured. Various factors, possibly responsible for such a variegated d 18 O values in the water of springs were studied, but statistical dependencies of oxygen isotope composition on springs' physical characteristics such as discharge, altitude of spring's orifice, air and water temperature, EC, longitude and latitude of the springs' cartographical position, aquifer lithology, groundwater circulation type and morphology of spring's orifice were very poor (Malík et al 2014).…”