A review of the geodynamic constraints on the development and evolution of geothermal systems in the Central Andean Volcanic Zone (18–28°Lat.S)

Reactivation of Fault Systems by Compartmentalized Hydrothermal Fluids in the Southern Andes Revealed by Magnetotelluric and Seismic Data

“…Stanton-Yonge et al, 2016;Veloso et al, 2019;Wrage et al, 2017). The majority of this WNW seismicity is located below 4 km, suggesting that the fault is located within the pre-Jurassic basement (Pavez et al, 2016).…”

“…Structural and mineralogical analyses of the faults have shown that fluid pressures between >85% and 98% of lithostatic stress can be required to trigger hybrid (extension plus shear) mode of failure (Roquer et al, 2017). It is therefore likely that fluid migration through these systems occurs in moments of seismic activity and conversely host hydrothermal reservoirs due to the entrapment of fluids during interseismic periods (Roquer et al, 2017; Veloso et al, 2019). Finally, rare outcrops of the ATF are characterized by multiple fault cores and dense vein networks within a wide damage zone, which prevent cross‐fault fluid flow due to their low permeability (Lara et al, 2004; Perez‐Flores et al, 2016).…”

“…This is interpreted to be an active ATF, as it shows similar characteristics to other ATF structures observed in different localities across the Andes. Namely, they are WNW trending, are discrete, blind, basement structures, and show spatial proximity to volcanoes, which can be emplaced at the intersection of the ATF and arc‐parallel fault systems (Cembrano & Lara, 2009; Chernicoff et al, 2002; Lara et al, 2004; Roquer et al, 2017; Sielfeld et al, 2017; Stanton‐Yonge et al, 2016; Veloso et al, 2019; Wrage et al, 2017). The majority of this WNW seismicity is located below 4 km, suggesting that the fault is located within the pre‐Jurassic basement (Pavez et al, 2016).…”

“…Tectonics of seismic activity and conversely host hydrothermal reservoirs due to the entrapment of fluids during interseismic periods (Roquer et al, 2017;Veloso et al, 2019). Finally, rare outcrops of the ATF are characterized by multiple fault cores and dense vein networks within a wide damage zone, which prevent cross-fault fluid flow due to their low permeability (Lara et al, 2004;Perez-Flores et al, 2016).…”

“…In an active volcanic arc, this complex interaction between hydrothermal fluids and structural systems can significantly influence tectonomagmatic processes, such as the distribution of volcanoes (Cembrano & Lara, 2009; Nakamura, 1977; Sielfeld et al, 2017; Tibaldi, 2005), the emplacement of ore deposits and plutons (Hedenquist & Lowenstern, 1994; Piquer et al, 2016), the localized structural and geochemical development of geothermal springs and fumaroles (Sanchez et al, 2013; Sibson, 1996; Tardani et al, 2016; Veloso et al, 2019), and the location, magnitude, frequency, and timing of crustal seismicity (Cox, 2016). Geophysical studies can image these active structural and hydromagmatic systems in order to map their architecture as a function of depth.…”