Abstract
Hydrogen-rich and water-rich fluids exert different control on dissolution mechanism of oxide and silicate minerals in the Earth’s interior. With Mgsilicate- H2 fluids, dissolution tends to be incongruent with the (Mg/Si)fluid < (Mg/Si)Mg-silicate with formation of SiOH and SiH4 complexes in the fluid (Shinozaki et al. 2013, 2014). In contrast, in Mg-silicate-H2O systems, Mg-silicate minerals in the mantle (pyroxene and forsterite) dissolve stoichiometrically (congruently) in aqueous fluids to at least 10 GPa pressure. Metasomatic alteration by H2-rich fluids enriches, therefore, the mantle in SiO2 compared with alteration by H2O fluid. This difference becomes increasingly important with mantle depth because the environment becomes more reducing, which results in an increase of H2/H2O fluids (Shinozaki et al. 2014, this issue). Chemical gradients with depth of the Earth could be affected by increased H2/H2O of mantle fluids whereby Mg/Si ratios, for example, will become variable. Silicate-H2 alteration processes likely also played major roles during the early, core-forming stages of the Earth. Such a process could be responsible for Mg/Si changes in the early silicate Earth.
© 2014 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Highlights and Breakthroughs
- An alternative to alteration and melting processes in the Earth: Reaction between hydrogen (H2) and oxide components in the Earth in space and time
- The crystallographic and petrogenetic significance of pegmatite phosphates
- Small grains and big implications: Accessory Ti- and Zr-minerals as petrogenetic indicators in HP and UHP marbles
- What Lurks in the Martian Rocks and Soil? Investigations of Sulfates, Phosphates, and Perchlorates
- Natural Fe-bearing oxides and sulfates from the Rio Tinto Mars analog site: Critical assessment of VNIR reflectance spectroscopy, laser Raman spectroscopy, and XRD as mineral identification tools
- Dissolution rates of amorphous Al- and Fe-phosphates and their relevance to phosphate mobility on Mars
- Stability and spectroscopy of Mg sulfate minerals: Role of hydration on sulfur isotope partitioning
- Synthesis and characterization of the Mars-relevant phosphate minerals Fe- and Mg-whitlockite and merrillite and a possible mechanism that maintains charge balance during whitlockite to merrillite transformation
- Minerals in the Human Body
- Determination of the concentration of asbestos minerals in highly contaminated mine tailings: An example from abandoned mine waste of Crètaz and Èmarese (Valle d’Aosta, Italy)
- Spinels Renaissance: The past, present, and future of those ubiquitous minerals and materials
- Pressure-volume equation of state for chromite and magnesiochromite: A single-crystal X-ray diffraction investigation
- The systematics of the spinel-type minerals: An overview
- Chemistry and Mineralogy of Earth’s Mantle
- Formation of SiH4 and H2O by the dissolution of quartz in H2 fluid under high pressure and temperature
- Identifying the spin transition in Fe2+-rich MgSiO3 perovskite from X-ray diffraction and vibrational spectroscopy
- Mantle-derived guyanaite in a Cr-omphacitite xenolith from Moses Rock diatreme, Utah
- Pluton assembly and the genesis of granitic magmas: Insights from the GIC pluton in cross section, Sierra Nevada Batholith, California
- First-principles molecular dynamics simulations of MgSiO3 glass: Structure, density, and elasticity at high pressure
- A new UHP metamorphic complex in the ~1.8 Ga Nagssugtoqidian Orogen of West Greenland
- Visible and short-wave infrared reflectance spectroscopy of REE fluorocarbonates
- Volatile abundances of coexisting merrillite and apatite in the martian meteorite Shergotty: Implications for merrillite in hydrous magmas
- Sb5+ and Sb3+ substitution in segnitite: A new sink for As and Sb in the environment and implications for acid mine drainage
- First-principles elasticity of monocarboaluminate hydrates
- Substitution of Ti3+ and Ti4+ in hibonite (CaAl12O19)
- Exploring the effect of lithium on pegmatitic textures: An experimental study
- XANES measurements of Cr valence in olivine and their applications to planetary basalts
- Z-contrast imaging and ab initio study on “d” superstructure in sedimentary dolomite
- Influence of temperature, pressure, and chemical composition on the electrical conductivity of granite
- Ti- and Zr-minerals in calcite-dolomite marbles from the ultrahigh-pressure Kimi Complex, Rhodope mountains, Greece: Implications for the P-T evolution based on reaction textures, petrogenetic grids, and geothermobarometry
- Ab initio thermodynamic and thermophysical properties of sapphirine end-members in the join Mg4Al8Si2O20-Mg3Al10SiO20
- The relation between Li ↔ Na substitution and hydrogen bonding in five-periodic singlechain silicates nambulite and marsturite: A single-crystal X-ray study
- Natural analogs of belite sulfoaluminate cement clinkers from Negev Desert, Israel
- Australian sedimentary opal-A and its associated minerals: Implications for natural silica sphere formation
- The 2H and 3R polytypes of sabieite, NH4Fe3+(SO4)2, from a natural fire in an oil-bearing shale near Milan, Ohio
- Letter
- Te-rich raspite, Pb(W0.56Te0.44)O4, from Tombstone, Arizona, U.S.A.: The first natural example of Te6+ substitution for W6+
- New Mineral Names
- Book Review
Articles in the same Issue
- Highlights and Breakthroughs
- An alternative to alteration and melting processes in the Earth: Reaction between hydrogen (H2) and oxide components in the Earth in space and time
- The crystallographic and petrogenetic significance of pegmatite phosphates
- Small grains and big implications: Accessory Ti- and Zr-minerals as petrogenetic indicators in HP and UHP marbles
- What Lurks in the Martian Rocks and Soil? Investigations of Sulfates, Phosphates, and Perchlorates
- Natural Fe-bearing oxides and sulfates from the Rio Tinto Mars analog site: Critical assessment of VNIR reflectance spectroscopy, laser Raman spectroscopy, and XRD as mineral identification tools
- Dissolution rates of amorphous Al- and Fe-phosphates and their relevance to phosphate mobility on Mars
- Stability and spectroscopy of Mg sulfate minerals: Role of hydration on sulfur isotope partitioning
- Synthesis and characterization of the Mars-relevant phosphate minerals Fe- and Mg-whitlockite and merrillite and a possible mechanism that maintains charge balance during whitlockite to merrillite transformation
- Minerals in the Human Body
- Determination of the concentration of asbestos minerals in highly contaminated mine tailings: An example from abandoned mine waste of Crètaz and Èmarese (Valle d’Aosta, Italy)
- Spinels Renaissance: The past, present, and future of those ubiquitous minerals and materials
- Pressure-volume equation of state for chromite and magnesiochromite: A single-crystal X-ray diffraction investigation
- The systematics of the spinel-type minerals: An overview
- Chemistry and Mineralogy of Earth’s Mantle
- Formation of SiH4 and H2O by the dissolution of quartz in H2 fluid under high pressure and temperature
- Identifying the spin transition in Fe2+-rich MgSiO3 perovskite from X-ray diffraction and vibrational spectroscopy
- Mantle-derived guyanaite in a Cr-omphacitite xenolith from Moses Rock diatreme, Utah
- Pluton assembly and the genesis of granitic magmas: Insights from the GIC pluton in cross section, Sierra Nevada Batholith, California
- First-principles molecular dynamics simulations of MgSiO3 glass: Structure, density, and elasticity at high pressure
- A new UHP metamorphic complex in the ~1.8 Ga Nagssugtoqidian Orogen of West Greenland
- Visible and short-wave infrared reflectance spectroscopy of REE fluorocarbonates
- Volatile abundances of coexisting merrillite and apatite in the martian meteorite Shergotty: Implications for merrillite in hydrous magmas
- Sb5+ and Sb3+ substitution in segnitite: A new sink for As and Sb in the environment and implications for acid mine drainage
- First-principles elasticity of monocarboaluminate hydrates
- Substitution of Ti3+ and Ti4+ in hibonite (CaAl12O19)
- Exploring the effect of lithium on pegmatitic textures: An experimental study
- XANES measurements of Cr valence in olivine and their applications to planetary basalts
- Z-contrast imaging and ab initio study on “d” superstructure in sedimentary dolomite
- Influence of temperature, pressure, and chemical composition on the electrical conductivity of granite
- Ti- and Zr-minerals in calcite-dolomite marbles from the ultrahigh-pressure Kimi Complex, Rhodope mountains, Greece: Implications for the P-T evolution based on reaction textures, petrogenetic grids, and geothermobarometry
- Ab initio thermodynamic and thermophysical properties of sapphirine end-members in the join Mg4Al8Si2O20-Mg3Al10SiO20
- The relation between Li ↔ Na substitution and hydrogen bonding in five-periodic singlechain silicates nambulite and marsturite: A single-crystal X-ray study
- Natural analogs of belite sulfoaluminate cement clinkers from Negev Desert, Israel
- Australian sedimentary opal-A and its associated minerals: Implications for natural silica sphere formation
- The 2H and 3R polytypes of sabieite, NH4Fe3+(SO4)2, from a natural fire in an oil-bearing shale near Milan, Ohio
- Letter
- Te-rich raspite, Pb(W0.56Te0.44)O4, from Tombstone, Arizona, U.S.A.: The first natural example of Te6+ substitution for W6+
- New Mineral Names
- Book Review