Groundwater Contributions to Waikite Geothermal Fluids

Abstract

Isotopic data are reported for hot springs in the Waikitearea. The data, along with chemical data, used to produce a consistent of mixing between deep chloride water and groundwater, with some being affectedby evaporation after rising to the surface. The constant ratio between chloride and bicarbonate concentrations shows that mixing takes place at depth before any boiling occurs. Reservoir temperatures using the Tritiumconcentrationsin springswiththe highest temperaturereservoirsare non-zero indicatingasmall input of 1960ís water. Groundwater from the nearby Paeroa Range is inferred. The weight of evidence the springs being a peripheral outflow on the margin of the Waiotapu system rather than being genetically related to Te Kopia.