Experiments and geochemical modeling of CO2 sequestration during hydrothermal basalt alteration

Gysi, Alexander P.; Stefánsson, Andri

doi:10.1016/j.chemgeo.2012.02.016

Cited by 73 publications

(42 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…wairakie, scolecite), albite, K-feldspar and epidote are also formed in the last stages of the reaction path of our high-T model runs. These alteration mineral assemblages, predicted by our high-T model runs, match well experimental results from Gysi and Stefánsson (2012), and are consistent with the observed distribution of hydrothermal minerals in boreholes from Krýsuvík and Krafla (Ármannsson et al, 1982).…”

Section: Secondary Minerals Formedsupporting

confidence: 76%

Reaction path models of magmatic gas scrubbing

et al. 2016

View full text Add to dashboard Cite

Gas-water-rock reactions taking place within volcano-hosted hydrothermal systems scrub reactive, water-soluble species (sulfur, halogens) from the magmatic gas phase, and as such play a major control on the composition of surface gas manifestations. A number of quantitative models of magmatic gas scrubbing have been proposed in the past, but no systematic comparison of model results with observations from natural systems has been carried out, to date. Here, we present the results of novel numerical simulations, in which we initialized models of hydrothermal gaswater-rock at conditions relevant to Icelandic volcanism. We focus on Iceland as an example of a "wet" volcanic region where scrubbing is widespread. Our simulations were performed (using the EQ3/6 software package) at shallow (temperature b 106°C; low-T model runs) and deep hydrothermal reservoir (200-250°C; high-T model runs) conditions. During the simulations, a high-temperature magmatic gas phase was added stepwise to an initial meteoric water, in the presence of a dissolving aquifer rock. At each step, the chemical compositions of coexisting aqueous solution and gas phase were returned by the model. The model-derived aqueous solutions have compositions that describe the maturation path of hydrothermal fluids, from immature, acidic Mg-rich waters, toward Na-Cl-rich mature hydrothermal brines. The modeled compositions are in fair agreement with measured compositions of natural thermal waters and reservoir fluids from Iceland. We additionally show that the composition of the modelgenerated gases is strongly temperature-dependent, and ranges from CO 2(g) -dominated (for temperatures ≤80°C) to H 2 O (g) -dominated (and more H 2 S (g) rich) for temperatures N 100°C. We find that this range of model gas compositions reproduces well the (H 2 O-CO 2 -S TOT ) compositional range of reservoir waters and surface gas emissions in Iceland. From this validation of the model in an extreme end-member environment of high scrubbing, we conclude that EQ3/6-based reaction path simulations offer a realistic representation of gas-water-rock interaction processes occurring underneath active magmatic-hydrothermal systems.

show abstract

Section: Secondary Minerals Formedsupporting

confidence: 76%

Reaction path models of magmatic gas scrubbing

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Understanding their alteration mechanisms and rates is a preliminary step toward the comprehension of different natural phenomena such as volcano slope stability (Schiffman et al, 2006), the chemical mass balance of the oceans (Walton et al, 2005), and the geological history of the planet Mars (Minitti et al, 2007). This knowledge may also lead to industrial applications such as geological storage of CO 2 (Stockmann et al, 2011;Gysi and Stefansson, 2012) and their use as a natural analog of nuclear glasses (Ewing, 1979;Crovisier et al, 2003;Libourel et al, 2011). In this last case, the long-term behavior of nuclear waste glasses will be predicted by building mechanistic models of their alteration (Grambow and Muller, 2001;Frugier et al, 2008) which cannot be directly validated over the long term.…”

Section: Introductionmentioning

confidence: 99%

Long-term alteration of basaltic glass: Mechanisms and rates

Parruzot

Jollivet

Rébiscoul

et al. 2015

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

“…Over the last few years, the issues involved in underground CO 2 sequestration have been included in the scientific literature mainly from a fluid property, fluid-dynamical, and geochemical viewpoint (e.g., Dethlefsen et al, 2012;Gysi and Stefansson, 2012;Balashov et al, 2013;Hosein and Alshakh, 2013;Poordad and Forutan, 2013)), but relatively fewer works have focused on the related geomechanical processes especially caprock integrity during CO 2 injection (e.g., Shukla et al, 2011;Dempsey et al, 2014;Vilarrasa, 2014)). …”

Section: Introductionmentioning

confidence: 99%