Ohaaki geothermal system: Refinement of a conceptual reservoir model

The deep liquid reservoir across the West and East Banks is proposed to result from mixing of two end-members: a major liquid upflow in the northwest, and a secondary upflow in the southeast with a greater contribution of magmatic volatiles. These deep fluids rise to shallower depth where they undergo various degrees of boiling, dilution and cooling with shallow steam-heated groundwater.