The Use of Noble Gases and Stable Isotopes to Indicate Temperatures and Mechanisms of Subsurface Boiling and (Less Certainly) Reservoir Depletion in Geothermal Systems

Salts are essentially insoluble in the low pressure steam produced from vapor-dominated systems. Hence, the normal chemical constituents used in studying hot-water geothermal systems prove ineffective in the study of subsurface conditions of vapor-dominated systems. This paper discusses how noble gases and stable isotopes of water may be used to fill this gap and may, in addition, provide a means of estimating the degree of reservoir depletion. 5 refs., 4 figs., 1 tab