Structural controls of the Domuyo geothermal field, Southern Andes (36°38′S), Argentina

GALETTO, ANTONELLA; GARCÍA, VÍCTOR; CASELLI, ALBERTO

JOURNAL OF STRUCTURAL GEOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2018 vol. 114 p. 76 - 94

0191-8141

Geothermal fields in subduction-related orogens are closely linked to areas characterized byyoung magmatic and tectonic activity, both in arc- and back-arc settings. The spatio-temporalinteraction of Quaternary volcanic complexes with regional extensional and transtensionalstructures might favor a hydrothermal circuit between meteoric water and magmatic fluids.This study encompasses a kinematic analysis of fault structures from the high-enthalpy systemlocated at the western flank of the Domuyo volcano in Argentina. An analysis of remote sensingdata was applied to detect regional lineaments, lineament density, and to identify fracturepatterns possibly associated with the different deformational stages documented in the area.These results were combined with detailed fracture analysis and kinematic study of mesoscalefaults, as well as existing geological, structural, and geophysical data. The integration suggeststhat the fluid dynamics of the Domuyo geothermal field are directly conditioned by pre-existingbasement structures that were reactivated as normal faults during Pliocene-to-Quaternarytimes. Furthermore, the intensely fracture late Triassic - early Jurassic units are interpreted asthe potential level for the reservoir. The fault reactivation was likely associated with theaccommodation of regional extension along pre-existing fault structures, and locally enhancedby hydrothermal effects of the Domuyo geothermal field.