Understanding the Caviahue-Copahue volcanic complex through kinematic solutions, paleotensors and analogue modelling
Registro en:
1873-0647
0895-9811
Autor
Vigide, Nicolás
Yagupsky, Daniel
Barcelona, Hernan
Augusto, Mariano
Caselli, Alberto Tomás
Institución
Resumen
Fil: Vigide, Nicolás. Observatorio Argentino de Vigilancia Volcánica (OAVV), Servicio Geológico Minero Argentino (SEGEMAR). Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Argentina. Fil: Yagupsky, Daniel. CONICET- IDEAN, Instituto de Estudios Andinos “Don Pablo Groeber”, Universidad de Buenos Aires,. Argentina. Fil: Barcelona, Hernan. CONICET- IDEAN, Instituto de Estudios Andinos “Don Pablo Groeber”, Universidad de Buenos Aires,. Argentina. Fil: Augusto, Mariano. CONICET- IDEAN, Instituto de Estudios Andinos “Don Pablo Groeber”, Universidad de Buenos Aires,. Argentina. Fil: Caselli, Alberto Tomás. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Argentina. This work aims to study the interaction between two of the most representative structural systems controlling the Caviahue-Copahue volcanic complex. To achieve this objective, a structural analysis based on outcrop-scale fault-slip data field surveys and analogue models were carried out. The deformation regime acting on the studied area was characterized, and the associated paleostresses were obtained from the kinematic data
inversion. The performed analysis in Caviahue-Copahue volcanic complex allowed to define two main sets of faults controlling the deformation of the area: NE-SW to ENE-WSW, and WNW-ESE to NW-SE, respectively. The first group comprises high-angle normal faults, resulting in a horst-and-graben setting with along-strike lengths up to 2 km. The second group shows strike-slip kinematics with a minor normal component. These NW-SE faults are related to the Miocene-Pliocene fissure-related volcanism and define the major caldera axis direction. In the geothermal area, the obtained paleostress orientation shows a consistent vertical σ1, denoting a local extensional regime. Regarding the geothermal field, the NE-SW extensional fault system is proposed as the main circulation pathways for hydrothermal fluids rising to the surface. The major NW-SE faults would act as barriers for this circulation.
The set of analogous experiments was used to contrast the obtained local structural kinematic results. Two
non-coaxial extensional events were established to achieve a local scale approach to the structural configuration observed in the area. Simulations aimed to understand the structural behavior of the superposition of non-coaxial extensive events; they allowed us to assess the role of the different fault sets surveyed in the field within the system. Particularly, our findings support that the NW-SE-oriented structures compartmentalize the subsequent NE-SW-oriented faults, acting on occasions as transfer zones. true This work aims to study the interaction between two of the most representative structural systems controlling the Caviahue-Copahue volcanic complex. To achieve this objective, a structural analysis based on outcrop-scale fault-slip data field surveys and analogue models were carried out. The deformation regime acting on the studied area was characterized, and the associated paleostresses were obtained from the kinematic data
inversion. The performed analysis in Caviahue-Copahue volcanic complex allowed to define two main sets of faults controlling the deformation of the area: NE-SW to ENE-WSW, and WNW-ESE to NW-SE, respectively. The first group comprises high-angle normal faults, resulting in a horst-and-graben setting with along-strike lengths up to 2 km. The second group shows strike-slip kinematics with a minor normal component. These NW-SE faults are related to the Miocene-Pliocene fissure-related volcanism and define the major caldera axis direction. In the geothermal area, the obtained paleostress orientation shows a consistent vertical σ1, denoting a local extensional regime. Regarding the geothermal field, the NE-SW extensional fault system is proposed as the main circulation pathways for hydrothermal fluids rising to the surface. The major NW-SE faults would act as barriers for this circulation.
The set of analogous experiments was used to contrast the obtained local structural kinematic results. Two
non-coaxial extensional events were established to achieve a local scale approach to the structural configuration observed in the area. Simulations aimed to understand the structural behavior of the superposition of non-coaxial extensive events; they allowed us to assess the role of the different fault sets surveyed in the field within the system. Particularly, our findings support that the NW-SE-oriented structures compartmentalize the subsequent NE-SW-oriented faults, acting on occasions as transfer zones.