Updated Resource Assessment and 3-D Geological Model of the Mita Geothermal System, Guatemala

Mita is a moderate temperature geothermal system that was discovered in 1997 during gold exploration in south-eastern Guatemala. This system is associated with bimodal basaltrhyolite volcanism, and occurs alongside (and overlapping with) the Cerro Blanco 2 million ounce epithermal gold deposit. Four 1000-1500m deep slim holes were drilled in 2008-09 to confirm the nature of the deep reservoir. This drilling program outlined an intermediate depth reservoir with temperatures in the region of 200°C, with a deeper inferred reservoir with temperatures of around 240°C. The intermediate geothermal system has been interpreted to be an outflow of a deeper system which migrates up along a horst fault. Following the latest exploration drilling phase, an updated conceptual model and 3D geological model have been created. This reservoir is liquid-dominated with a sodiumchloride-bicarbonate composition, TDS of about 1,900 mg/kg and gas content of 0.4 wt%. The shallow outflow from this system appears to be linked to the thick Salinas rhyolite encountered at shallow depths. Commercial electricity generation is feasible from wells targeted along the Eastern Horst Fault (EHF). The extraction from these wells will also assist in the dewatering and cooling of the Cerro Blanco gold deposit.