79 ACTA CARSOLOGICA 29/1 5 79-92 LJUBLJANA 2000 COBISS: 1.08 Prejeto / received: 6. 3. 2000 1 Institute “Joæef Stefan”, Dept. of Environmental Sciences, LJUBLJANA, SLOVENIA A STABLE ISOTOPE INVESTIGATION OF THE CLASSICAL KARST AQUIFER: EVALUATING KARST GROUNDWATER COMPONENTS FOR WATER QUALITY PRESERVATION RAZISKAVA KRA[KEGA VODONOSNIKA S STABILNIMI IZOTOPI DANIEL H. DOCTOR 1 & SONJA LOJEN 1 & MILENA HORVAT 1