The hydrothermal-volcanic system of Rincon de la Vieja volcano (Costa Rica): A combined (inorganic and organic) geochemical approach to understanding the origin of the fluid discharges and its possible application to volcanic surveillance

Geochemistry of fluid discharges from Peteroa volcano (Argentina-Chile) in 2010–2015: Insights into compositional changes related to the fluid source region(s)

“…The relatively slow kinetic of reaction (4) would explain the limited variations of the CH 4 /CO 2 ratio (less than 0.5 log-units) in response to the strong compositional changes occurred in 2012. On the contrary, dehydrogenation reactions of the C 2 and C 3 alkene-alkane pairs are considered particularly sensitive to changes of chemical-physical conditions (e.g., Seewald, 1994;Capaccioni and Mangani, 2001;Capaccioni et al, 2004;Taran and Giggenbach, 2003;Tassi et al, 2005). A generic expression for dehydrogenation of alkanes can be expressed, as follows:…”

The Geothermal Resource in the Guanacaste Region (Costa Rica): New Hints From the Geochemistry of Naturally Discharging Fluids

“…In contrast, gases from (i) the Miravalles geothermal gases (GW), (ii) the active crater (AC) of Rincón de la Vieja, and (iii) AL were marked by a significant N 2 -excess (Figure 3). The GW gases were expected to show a limited interaction with the shallow environment, being preserved by the tubing of the wells, whereas the low air contamination of AC was likely related to a strong magmatic fluid inputs, considering that this gas collected from a high-flux emission at the border of the hyperacidic and extremely active carter lake of Rincón de la Vieja (Tassi et al, 2005). The high N 2 /Ar ratios of the AL gases were surprising since these gas emissions were apparently similar to the other hydrothermal discharges, i.e., low flux bubbling pools with a relatively low (<100 • C) outlet temperature ( Table 1).…”

“…Data from literature (Tassi et al, 2005) of Rincón de la Vieja thermal manifestations are also reported. The δ 13 C-CO 2 values of gases from the N flank of Tenorio (Figure 1) were significantly more negative (from −5.44 to −2.80‰ vs. V-PDB) with respect to those from the other thermal discharges (from −2.71 to −1.16‰ vs. V-PDB).…”

“…Data from literature of some of these thermal fluid discharges from Rincón de la Vieja and Miravalles that were sampled in 1984 and1987 (BOR1 andPA;Giggenbach and Corrales, 1992), as well as in 1998, 1999Tassi et al, 2005), are also reported. The dataset also includes the chemical composition of gases collected from different sites within GGP in 1987 and1990 (MZ, TM, andGB;Giggenbach and Corrales, 1992), 1998 (GB; Gherardi et al, 2002), 1999Tassi et al, 2005), as well as that of gases from exploitation wells of the Miravalles geothermal plant (PGM01, PGM05, PGM10, PGM11, PGM12, PGM17, PGM31, and PGM49; Gherardi et al, 2002). The thermal manifestations consist of bubbling and boiling pools with temperatures ranging from 21 to 99 • C. The chemical composition of the dry fraction of the fluids (the concentrations of steam were mostly controlled by the liquid phase at the surface) was dominated by CO 2 (up to 996 mmol/mol), followed by N 2 (from 2 to 53 and mmol/mol).…”

Volcanic Lakes

“…Intermediate lakes are rare, which have an input of a mixed volcanic fluid but do not reach a pH low enough to let CO 2 escape. Concentrated pools of exotic S-Cl-rich water are found where the lake absorbs largely unprocessed raw volcanic gases, such as in the Keli Mutu lakes (Pasternack and Varekamp 1994) and Kawah Putih lake, both in Indonesia (Sriwana et al 2000), and Poás and Rincón de la Vieja lakes in Costa Rica (Tassi et al 2005(Tassi et al , 2009.…”