Water in the deep Earth: The dielectric constant and the solubilities of quartz and corundum to 60kb and 1200°C

Sverjensky, Dimitri A.; Harrison, Brandon; Azzolini, David

doi:10.1016/j.gca.2013.12.019

Cited by 235 publications

(225 citation statements)

References 106 publications

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“…Such reaction energetics is further supported by the close chemical affinities of the HS − and S − 3 ions for Au + according to the general Au and S chemistry (25) and first-principles calculations on aqueous solutions of this and previous (26) studies. In addition, similar values of the electrostatic Born parameter (ω ≈ 0.8 × 10 5 cal/mol) derived in the framework of the revised HelgesonKirkham-Flowers (HKF) equation of state (27,28) for S − 3 (24) and AuðHSÞ − 2 (6) imply a close evolution with temperature and pressure of the hydration energies of both ions in aqueous solution. These similarities, together with an isocoulombic nature of reaction (R1), strongly suggest that the reaction energetics is constant over a wide T-P range.…”

Section: Resultssupporting

confidence: 59%

Sulfur radical species form gold deposits on Earth

Pokrovski

Kokh

Guillaume

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

121

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Current models of the formation and distribution of gold deposits on Earth are based on the long-standing paradigm that hydrogen sulfide and chloride are the ligands responsible for gold mobilization and precipitation by fluids across the lithosphere. Here we challenge this view by demonstrating, using in situ X-ray absorption spectroscopy and solubility measurements, coupled with molecular dynamics and thermodynamic simulations, that sulfur radical species, such as the trisulfur ion S − 3 , form very stable and soluble complexes with Au + in aqueous solution at elevated temperatures (>250°C) and pressures (>100 bar). These species enable extraction, transport, and focused precipitation of gold by sulfur-rich fluids 10-100 times more efficiently than sulfide and chloride only. As a result, S − 3 exerts an important control on the source, concentration, and distribution of gold in its major economic deposits from magmatic, hydrothermal, and metamorphic settings. The growth and decay of S − 3 during the fluid generation and evolution is one of the key factors that determine the fate of gold in the lithosphere.gold | sulfur | ore deposit | hydrothermal fluid | trisulfur ion

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Section: Resultssupporting

confidence: 59%

Sulfur radical species form gold deposits on Earth

Pokrovski

Kokh

Guillaume

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

121

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“…To rigorously evaluate the energy sources for microbial life within the subduction zone forearc, better constraints are needed for the fluid influxes from the subduction zone and how these slabderived fluids interact with the forearc. Increasing sophisticated fluid speciation models coupled to fluid-rock interaction simulations and experiments at high pressures and temperatures (56,57) will provide critical insights into this problem.…”

Section: ) Indicate Thatmentioning

confidence: 99%

Subduction zone forearc serpentinites as incubators for deep microbial life

Plümper

Geisler

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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Serpentinization-fueled systems in the cool, hydrated forearc mantle of subduction zones may provide an environment that supports deep chemolithoautotrophic life. Here, we examine serpentinite clasts expelled from mud volcanoes above the Izu-BoninMariana subduction zone forearc (Pacific Ocean) that contain complex organic matter and nanosized Ni-Fe alloys. Using time-of-flight secondary ion mass spectrometry and Raman spectroscopy, we determined that the organic matter consists of a mixture of aliphatic and aromatic compounds and functional groups such as amides. Although an abiotic or subduction slab-derived fluid origin cannot be excluded, the similarities between the molecular signatures identified in the clasts and those of bacteria-derived biopolymers from other serpentinizing systems hint at the possibility of deep microbial life within the forearc. To test this hypothesis, we coupled the currently known temperature limit for life, 122°C, with a heat conduction model that predicts a potential depth limit for life within the forearc at ∼10,000 m below the seafloor. This is deeper than the 122°C isotherm in known oceanic serpentinizing regions and an order of magnitude deeper than the downhole temperature at the serpentinized Atlantis Massif oceanic core complex, MidAtlantic Ridge. We suggest that the organic-rich serpentinites may be indicators for microbial life deep within or below the mud volcano. Thus, the hydrated forearc mantle may represent one of Earth's largest hidden microbial ecosystems. These types of protected ecosystems may have allowed the deep biosphere to thrive, despite violent phases during Earth's history such as the late heavy bombardment and global mass extinctions.deep biosphere | serpentinization | subduction zone | forearc

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“…Na + , K + , that may M.E. Galvez et al / Earth and Planetary Science Letters Sverjensky et al, 2014) along with density values from Zhang and Duan (2005).…”

Section: Introductionmentioning

confidence: 99%

“…The g • for ions in pure H 2 O can be determined using the HKF equations of state (Helgeson et al, 1981) as revised and extended by Tanger and Helgeson (1988) and Shock et al (1992). Here, (ε r ) H 2 O is computed at P and T with an EoS from Sverjensky et al (2014) with input H 2 O densities from Zhang and Duan (2005) (Fig. 1).…”

Section: Introductionmentioning

confidence: 99%