Selected Chemical Analysis and Geothermometry of Hot Spring Waters from the Calabozos Caldera, Central Chile

Abstract

Hot springs discharging from the active hydrothermal system associated with the Calabozos caldera, Chile, have measured orifice temperatures as high as 98.5°C and calculated geothermometers temperatures as high as 250°C. Three types of spring waters can be identified form the chemical analyses: a Na=C1 type, a Na-HCO3 type and a Na-mixed anion type. Chloride enthalpy relations indicate that the hydrothermal reservoir water may attain temperatures near 342°C and that most spring waters are mixed with cold meteoric water. Despite the proximity of Mesozoic marine gypsum deposits, the C1/Br weight ratio of the Calabozos spring waters does not appear to indicate that these waters have a indicate "marine" signature.