Geochemical and isotopic evidences of magmatic inputs in the hydrothermal reservoir feeding the fumarolic discharges of Tacora volcano (northern Chile)

Gas emissions from five volcanoes in northern Chile and implications for the volatiles budget of the Central Volcanic Zone

“…Gas samples from Villarrica, which originate from a persistent lava lake, represent the best available compositional proxy for the magmatic gas end‐member in Chile. In contrast, the CO 2 ‐rich (CO 2 /SO 2 ~ 27.9) signature of Tacora gas [ Capaccioni et al , ] is typical of residual fluids formed after prolonged gas‐water‐rock interactions [ Symonds et al , ] and is therefore taken as representative of the hydrothermal compositional end‐member.…”

“…(b) Temperature dependence of CO 2 /S tot molar ratios in gas samples from Alitar (AL), Tupungatito (TU), Olca (OC), Ollagüe (OG), Tacora (TA), Irruputuncu (IR), Putana (PU), Láscar (LC), and Lastarria (LT) in the CVZ within northern Chile, and from Villarrica (VI) in the SVZ. Additional data are from Aguilera et al [], Capaccioni et al [], Benavente et al [], Tassi et al [], and Shinohara and Witter [].…”

“…The scanning Mini‐DOAS and UV camera measurements made at Lastarria, Láscar, Putana, San Pedro, and Ollagüe lead to a cumulative SO 2 output from the five volcanoes of ~1800 t d −1 (or 6.6 × 10 5 t yr −1 ) in 2012–2013 (Table ). Three additional volcanoes (Irruputuncu, Olca, and Tacora) in this arc segment are reported to comprise high‐temperature fumaroles [ Capaccioni et al , ; Tassi et al , ]. The strongest S emitter of the three volcanoes is probably Irruputuncu, a volcano that typically vents S‐rich gas [ Tassi et al , ].…”

HCl degassing from extremely acidic crater lakes: preliminary results from experimental determinations and implications for geochemical monitoring

“…With the observation of acidic gas species in boilingtemperature fumaroles (Turrialba, Tacora, Meakandake; Vaselli et al 2009;Capaccioni et al 2011;Shinohara et al 2011), and HCl degassing at even lower-temperature conditions (this study), the presence of an extremely acidic aquifer beneath fumaroles has also temporal buffer capacities. The hydrodynamics in aquifers is even slower than for lakes (low porosity/permeability v. open-water systems), and could thus additionally slow down the signal of a fumarole at the surface.…”

“…Degassing of acid species from boiling temperature fumaroles has been temporarily detected at just a few volcanoes (Turrialba, Tacora and Meakandake), often preceding phreatic eruption activity and probably triggered by the input of a hot magmatic gas phase (Vaselli et al 2009;Capaccioni et al 2011;Shinohara et al 2011). …”