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 Victorian 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, that suggest that they were derived from local meteoric water recharged under cooler climatic conditions than present. delta(13)C values of entrained CO2 (-10.4 to -7.0 parts per thousand) and dissolved inorganic carbon (-3.9 to -0.1 parts per thousand) imply that the C was probably derived from outgassing of Recent igneous rocks within the Newer Volcanic Province. The waters 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-rock interaction. (C) 2000 Elsevier Science B.V. All rights reserved.