The Domuyo volcanic system: an enormous geothermal potential in Argentine Patagonia.

CHIODINI G; LICCIOLI C; VASELLI O; CALABRESE S; CALIRO S; CASELLI A; AGUSTO M

JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 274 p. 71 - 77

0377-0273

A geochemical survey of the main thermal waters discharging inthe southwestern part of the Domuyo volcanic complex (Argentine), whoselatest volcanic activity dates back to 0.11 Ma years, has highlighted thestrikingly high thermal release from this remote site of Patagonia. Thethermal water discharges are mostly Na-Cl in composition and have TDSvalues up to 3.78 g L-1 (El Humazo). A simple hydrogeochemical approachhas evidenced that 1,100 to 1,300 L s-1 of boiling waters, which areaffected by shallow processes of steam separation, flow from the maintributaries into the main drainage system of the area (Rio Varvarco). Adramatic increase of the most conservative species such as Na, Cl and Lifrom the Rio Varcarco down- to upstream was observed and related to thesole contribution of the hydrothermal fluids. The equilibriumtemperatures of the discharging fluids calculated on the basis of the Na-K-Mg geothermometer are between 190 and 230 °C. If we refer to a liquidoriginally at 220 °C (enthalpy = 944 J g-1), the thermal energy releasecan be estimated as high as 1.1 ± 0.2 GW, a value that is much higherthan the natural release of heat in other important geothermal fieldsworldwide, e.g. Mutnovsky (Russia), Wairakei (New Zealand) and LassenPeak (USA). For instance this value is the second ever measured advectiveheat flux from any hydrothermal system of the Earth after Yellowstone.These figures indicate the huge geothermal potential in this part of theDomuyo volcano.