O, H, C isotope geochemistry of carbonated mineral springs in central Victoria, Australia: sources of gas and water-rock interaction during dying basaltic volcanism

Waters discharging from carbonated cold mineral springs in the central Vict orian Highlands of Australia have delta(2)H and delta(18)O values of -45 to -35 parts per thousand and -8 to -5.5 parts per thousand, respectively, th at suggest that they were derived from local meteoric water recharged under cooler climatic conditions than present. delta(13)C values of entrained CO 2 (-10.4 to -7.0 parts per thousand) and dissolved inorganic carbon (-3.9 t o -0.1 parts per thousand) imply that the C was probably derived from outga ssing of Recent igneous rocks within the Newer Volcanic Province. The water s lie to the left of both local and global meteoric water lines due to CO2 exsolution from waters that were never involved in high-temperature water-r ock interaction. (C) 2000 Elsevier Science B.V. All rights reserved.