Aqueous fluid composition in CI chondritic materials: Chemical equilibrium assessments in closed systems

Zolotov, M. Yu.

doi:10.1016/j.icarus.2012.05.036

Cited by 89 publications

(66 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We performed an equilibrium calculation in a Ca-C-O-H-Fe system under the presence of pyrene (C 16 H 10 ), magnetite (Fe 3 O 4 ), and siderite (FeCO 3 ). Pyrene was included as a representative of organic matter similarly to the model by Zolotov (2012 …”

Section: Redox Conditions Under Which Calcite Precipitatedmentioning

confidence: 99%

“…Therefore, the fluids from which the type 1 calcites precipitated had higher pH and/or higher [Ca 2+ ] than fluids from which the type 2 calcites precipitated. For instance, if we adopt pH, defined as Àlog[H + ], =10.5, as expected for fluids in equilibrium with CI chondrite-type materials at a water/rock ratio = 1 (Zolotov, 2012), a minimum [Ca 2+ ] of 5 Â 10 À5 (mol/l) is required for type 1 calcite precipitation, which is higher than the value of 3 Â 10 À6 for type 2 calcite precipitation. These [Ca 2+ ] values are not unreasonable during alteration (Zolotov, 2012).…”

Section: Redox Conditions Under Which Calcite Precipitatedmentioning

confidence: 99%

See 1 more Smart Citation

Comprehensive study of carbon and oxygen isotopic compositions, trace element abundances, and cathodoluminescence intensities of calcite in the Murchison CM chondrite

Fujiya

Sugiura

Marrocchi

et al. 2015

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Section: Redox Conditions Under Which Calcite Precipitatedmentioning

confidence: 99%

Section: Redox Conditions Under Which Calcite Precipitatedmentioning

confidence: 99%

Comprehensive study of carbon and oxygen isotopic compositions, trace element abundances, and cathodoluminescence intensities of calcite in the Murchison CM chondrite

Fujiya

Sugiura

Marrocchi

et al. 2015

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

“…Lower pH would allow CO to survive longer. Zolotov (2012) modeled chemical equilibrium between cometary volatiles and CI chondrite solids down to 0 o C, and found that the predicted equilibrium pH is about two units above neutrality. The relatively high pH in these systems is dictated by reactions between ultramafic silicate minerals and the aqueous solution.…”

Section: Fate Of Co In a Subsurface Oceanmentioning

confidence: 99%

Prerequisites for explosive cryovolcanism on dwarf planet-class Kuiper belt objects

Neveu

Desch

Shock

et al. 2015

Icarus

View full text Add to dashboard Cite

Explosive extrusion of cold material from the interior of icy bodies, or cryovolcanism, has been observed on Enceladus and, perhaps, Europa, Triton, and Ceres. It may explain the observed evidence for a young surface on Charon (Pluto's surface is masked by frosts). Here, we evaluate prerequisites for cryovolcanism on dwarf planet-class Kuiper belt objects (KBOs). We first review the likely spatial and temporal extent of subsurface liquid, proposed mechanisms to overcome the negative buoyancy of liquid water in ice, and the volatile inventory of KBOs. We then present a new geochemical equilibrium model for volatile exsolution and its ability to drive upward crack propagation. This novel approach bridges geophysics and geochemistry, and extends geochemical modeling to the seldom-explored realm of liquid water at subzero temperatures. We show that carbon monoxide (CO) is a key volatile for gas-driven fluid ascent; whereas CO 2 and sulfur gases only play a minor role. N 2 , CH 4 , and H 2 exsolution may also drive explosive cryovolcanism if hydrothermal activity produces these species in large amounts (a few percent with respect to water). Another important control on crack propagation is the internal structure: a hydrated core makes explosive cryovolcanism easier, but an undifferentiated crust does not. We briefly discuss other controls on ascent such as fluid freezing on crack walls, and outline theoretical advances necessary to better understand cryovolcanic processes. Finally, we make testable predictions for the 2015 New Horizons flyby of the Pluto-Charon system.

show abstract

“…Because silica solubility increases with fluid alkalinity, the minimum temperature allowing silica nanoparticle formation on subsequent cooling rises to ,190 uC at pH 10.5 if the hydrothermal fluid pH were to increase by one when mixing with the subsurface ocean water (Methods and ref. 20).…”

mentioning

confidence: 99%

Ongoing hydrothermal activities within Enceladus

Hsu

Postberg

Sekine

et al. 2015

Nature

435

410

View full text Add to dashboard Cite

Detection of sodium-salt-rich ice grains emitted from the plume of the Saturnian moon Enceladus suggests that the grains formed as frozen droplets from a liquid water reservoir that is, or has been, in contact with rock. Gravitational field measurements suggest a regional south polar subsurface ocean of about 10 kilometres thickness located beneath an ice crust 30 to 40 kilometres thick. These findings imply rock-water interactions in regions surrounding the core of Enceladus. The resulting chemical 'footprints' are expected to be preserved in the liquid and subsequently transported upwards to the near-surface plume sources, where they eventually would be ejected and could be measured by a spacecraft. Here we report an analysis of silicon-rich, nanometre-sized dust particles (so-called stream particles) that stand out from the water-ice-dominated objects characteristic of Saturn. We interpret these grains as nanometre-sized SiO2 (silica) particles, initially embedded in icy grains emitted from Enceladus' subsurface waters and released by sputter erosion in Saturn's E ring. The composition and the limited size range (2 to 8 nanometres in radius) of stream particles indicate ongoing high-temperature (>90 °C) hydrothermal reactions associated with global-scale geothermal activity that quickly transports hydrothermal products from the ocean floor at a depth of at least 40 kilometres up to the plume of Enceladus.

show abstract

Aqueous fluid composition in CI chondritic materials: Chemical equilibrium assessments in closed systems

Cited by 89 publications

References 66 publications

Comprehensive study of carbon and oxygen isotopic compositions, trace element abundances, and cathodoluminescence intensities of calcite in the Murchison CM chondrite

Comprehensive study of carbon and oxygen isotopic compositions, trace element abundances, and cathodoluminescence intensities of calcite in the Murchison CM chondrite

Prerequisites for explosive cryovolcanism on dwarf planet-class Kuiper belt objects

Ongoing hydrothermal activities within Enceladus

Contact Info

Product

Resources

About