Radiocarbon Concentration and Origin of Thermal Karst Waters in the Region of the Bükk Mountains, Northeastern Hungary

Ede Hertelendi, Mihály Veres, István Futó, Éva Svingor, Lajos Mikó, László Lénárt, József Deák, Miklós Süveges
1995 Radiocarbon: An International Journal of Cosmogenic Isotope Research  
Karst springs are abundant in Hungary, and many are thermal (temperatures >30°). As thermal springs are a significant part of Hungary's water resources, it is important to quantify their travel times in the karst systems. Thus, we chose to measure T and δ18O in the water and δ13C and14C in dissolved inorganic carbon (DIC) in water from 50 thermal and nonthermal springs and wells in the Bükk Mountains, northeastern Hungary. Environmental isotope data confirm the karst water-flow pattern
more » ... d by earlier studies. We found the water in warm springs and boreholes to be mixtures of cold young and old thermal water. We also determined short mean-residence times for some large cold springs. The14C activities measured in these springs indicate that the recharge area of the karst aquifer is open to the atmosphere, and atmospheric CO2contributes to the14C activity of these groundwaters. We observed good correlation between14C and3H activities and we determined negative correlations between14C concentration and δ13C values and temperature. From the δ18O values of the oldest thermal waters, we attribute their origin to precipitation during colder temperatures than at present.
doi:10.1017/s0033822200031039 fatcat:warqkkybu5fgxlo2f76mbl7yzq