engleski

Comparison of the 14^C activity of groundwater and recent tufa from karst areas in Yugoslavia and Czechoslovakia

14^C activity of dissolved inorganic carbon (DIC) in water and in recent tufa samples in several karst areas of Yugoslavia and Czechoslovakia was measured. Groundwater from 11 karst springs were measured for their isotopic content (14^C, 3^H, 13^C), chemical compositions (HCO_3, Ca^2+, Mg^2+) and physico- chemical properties (temperature, pH).Seasonal variations of the 14^C activity of DIC in two karst springs in Plitvice Lakes area, Zugoslavia, were measured systematically from 1979-1987. 14^C activity of recent tufa samples from several locations downstream were also measured. The activity of DIC in karst spring waters in both countries ranged from 63-87 pMC, whivh is attributed to differences in geologic structure ot the recharge area, topsoil thickness and composition. Grouping of 14^C activities of DIC ca (82± ; 4)% is evident. Tritium activity at all the springs indicated short mean residence time (1-10 yr). Concentration of HCO_3, Ca^2+ and Mg^2+ in spring water varied with geomorphology. 14^C activity of streamwater and recent tufa increased downstream from karst springs due to the exchange between atmospheric CO_2 and DIC.

radiocarbon ; tufa ; groundwater

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