Chemometrics Applied to the Fluid of Fields in the Taupo Volcanic Zone, New Zealand

Abstract

Weirbox water chemistries of geothermal fluids discharged from Kawerau, Rotorua, Waiotapu, Te Kopia, Orakeikorako, Ohaaki, Mokai, Rotokawa, Wairakei, Tauhara and Tokaanu geothermal fields were selected for trial application of multivariate statistical techniques. Correlation coefficients identified inter-element associations, which were further quantified by R-mode factor analysis. These methods identified sources and controls on the distribution of major and trace constituents in the water, and may form the basis of a future mixing model. Cluster analysis groups waters of similar chemistry, and shows promise as a method to recognise fields with a common reservoir, and to distinguish between wells within a field which discharge waters from shallow and deep The techniques require further development but, as this study shows, are a potential tool in the evaluation of geothermal fluid chemistry.