The mobility of Nb in rutile-saturated NaCl- and NaF-bearing aqueous fluids from 1–6.5 GPa and 300–800 °C
-
,
Abstract
Rutile (TiO2) is an important host phase for high field strength elements (HFSE) such as Nb in metamorphic and subduction zone environments. The observed depletion of Nb in arc rocks is often explained by the hypothesis that rutile sequesters HFSE in the subducted slab and overlying sediment, and is chemically inert with respect to aqueous fluids evolved during prograde metamorphism in the forearc to subarc environment. However, field observations of exhumed terranes, and experimental studies, indicate that HFSE may be soluble in complex aqueous fluids at high pressure (i.e., >0.5 GPa) and moderate to high temperature (i.e., >300 °C). In this study, we investigated experimentally the mobility of Nb in NaCl- and NaF-bearing aqueous fluids in equilibrium with Nb-bearing rutile at pressure-temperature conditions applicable to fluid evolution in arc environments. Niobium concentrations in aqueous fluid at rutile saturation were measured directly by using a hydrothermal diamondanvil cell (HDAC) and synchrotron X‑ray fluorescence (SXRF) at 2.1 to 6.5 GPa and 300-500 °C, and indirectly by performing mass loss experiments in a piston-cylinder (PC) apparatus at ~1 GPa and 700-800 °C. The concentration of Nb in a 10 wt% NaCl aqueous fluid increases from 6 to 11 μg/g as temperature increases from 300 to 500 °C, over a pressure range from 2.1 to 2.8 GPa, consistent with a positive temperature dependence. The concentration of Nb in a 20 wt% NaCl aqueous fluid varies from 55 to 150 μg/g at 300 to 500 °C, over a pressure range from 1.8 to 6.4 GPa; however, there is no discernible temperature or pressure dependence. The Nb concentration in a 4 wt% NaF-bearing aqueous fluid increases from 180 to 910 μg/g as temperature increases from 300 to 500 °C over the pressure range 2.1 to 6.5 GPa. The data for the F-bearing fluid indicate that the Nb content of the fluid exhibits a dependence on temperature between 300 and 500 °C at ≥2 GPa, but there is no observed dependence on pressure. Together, the data demonstrate that the hydrothermal mobility of Nb is strongly controlled by the composition of the fluid, consistent with published data for Ti. At all experimental conditions, however, the concentration of Nb in the fluid is always lower than coexisting rutile, consistent with a role for rutile in moderating the Nb budget of arc rocks.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Highlights and Breakthroughs. Going small: Nanoscale geochronology using atom probe tomography
- Highlights and Breakthroughs. Bubbles do matter!
- Outlooks in Earth and Planetary Materials. Assuring the future of mineralogy
- Review. NMR and computational molecular modeling studies of mineral surfaces and interlayer galleries: A review
- Presidential Address. Nano- and micro-geochronology in Hadean and Archean zircons by atom-probe tomography and SIMS: New tools for old minerals
- 222Rn and 220Rn emanations as a function of the absorbed α-doses from select metamict minerals
- Compositional variation and timing of aluminum phosphate-sulfate minerals in the basement rocks along the P2 fault and in association with the McArthur River uranium deposit, Athabasca Basin, Saskatchewan, Canada
- Kinetics of deuteration in andradite and garnet
- Aluminum and iron behavior in glasses from destabilized spinels: A record of fluid/meltmineral interaction in mantle xenoliths from Massif Central, France
- Elastic plastic self-consistent (EPSC) modeling of plastic deformation in fayalite olivine
- Sc- and REE-rich tourmaline replaced by Sc-rich REE-bearing epidote-group mineral from the mixed (NYF+LCT) Kracovice pegmatite (Moldanubian Zone, Czech Republic)
- Inter-laboratory comparison of fission track confined length and etch figure measurements in apatite
- Origin and significance of the yellow cathodoluminescence (CL) of quartz
- Synthesis of large and homogeneous single crystals of water-bearing minerals by slow cooling at deep-mantle pressures
- A new mineral from the Bellerberg, Eifel, Germany, intermediate between mullite and sillimanite
- Yusupovite, Na2Zr(Si6O15)(H2O)3, a new mineral species from the Darai-Pioz alkaline massif and its implications as a new microporous filter for large ions
- Transition metal incorporation into mackinawite (tetragonal FeS)
- Pink color in Type I diamonds: Is deformation twinning the cause?
- Effect of crystal defects on diamond morphology during dissolution in the mantle
- Silica polymorphs in lunar granite: Implications for granite petrogenesis on the Moon
- Identification of nanocrystalline goethite in reduced clay formations: Application to the Callovian-Oxfordian formation of Bure (France)
- Dependence of R fluorescence lines of rubies on Cr3+ concentration at various temperatures, with implications for pressure calibrations in experimental apparatus
- Topotactic and reconstructive changes at high pressures and temperatures from Cs-natrolite to Cs-hexacelsian
- High-pressure equation of state and phase transition in PbAl2Si2O8 feldspar
- Enthalpies of formation of rare earth niobates, RE3NbO7
- Weathering of galena: Mineralogical processes, hydrogeochemical fluid path modeling, and estimation of the growth rate of pyromorphite
- Dissolved Cl, oxygen fugacity, and their effects on Fe behavior in a hydrous rhyodacitic melt
- The mobility of Nb in rutile-saturated NaCl- and NaF-bearing aqueous fluids from 1–6.5 GPa and 300–800 °C
- The effect of the [Na/(Na+K)] ratio on Fe speciation in phonolitic glasses
- Technical Note: Calculation of stoichiometry from EMP data for apatite and other phases with mixing on monovalent anion sites
- The effects of immobilized carboxylic-functional groups on the dynamics of phase transformation from amorphous to octacalcium phosphate
- Letter. Structural and chemical characterization of Mg[(Cr,Mg)(Si,Mg)]O4, a new post-spinel phase with sixfold-coordinated silicon
- Letter. Partition of Al between Phase D and Phase H at high pressure: Results from a simultaneous structure refinement of the two phases coexisting in a unique grain
- Letter. The speciation of carbon monoxide in silicate melts and glasses
- Letter. Lightning-induced shock lamellae in quartz
- New Mineral Names
- Book Review
- Errata
Articles in the same Issue
- Highlights and Breakthroughs. Going small: Nanoscale geochronology using atom probe tomography
- Highlights and Breakthroughs. Bubbles do matter!
- Outlooks in Earth and Planetary Materials. Assuring the future of mineralogy
- Review. NMR and computational molecular modeling studies of mineral surfaces and interlayer galleries: A review
- Presidential Address. Nano- and micro-geochronology in Hadean and Archean zircons by atom-probe tomography and SIMS: New tools for old minerals
- 222Rn and 220Rn emanations as a function of the absorbed α-doses from select metamict minerals
- Compositional variation and timing of aluminum phosphate-sulfate minerals in the basement rocks along the P2 fault and in association with the McArthur River uranium deposit, Athabasca Basin, Saskatchewan, Canada
- Kinetics of deuteration in andradite and garnet
- Aluminum and iron behavior in glasses from destabilized spinels: A record of fluid/meltmineral interaction in mantle xenoliths from Massif Central, France
- Elastic plastic self-consistent (EPSC) modeling of plastic deformation in fayalite olivine
- Sc- and REE-rich tourmaline replaced by Sc-rich REE-bearing epidote-group mineral from the mixed (NYF+LCT) Kracovice pegmatite (Moldanubian Zone, Czech Republic)
- Inter-laboratory comparison of fission track confined length and etch figure measurements in apatite
- Origin and significance of the yellow cathodoluminescence (CL) of quartz
- Synthesis of large and homogeneous single crystals of water-bearing minerals by slow cooling at deep-mantle pressures
- A new mineral from the Bellerberg, Eifel, Germany, intermediate between mullite and sillimanite
- Yusupovite, Na2Zr(Si6O15)(H2O)3, a new mineral species from the Darai-Pioz alkaline massif and its implications as a new microporous filter for large ions
- Transition metal incorporation into mackinawite (tetragonal FeS)
- Pink color in Type I diamonds: Is deformation twinning the cause?
- Effect of crystal defects on diamond morphology during dissolution in the mantle
- Silica polymorphs in lunar granite: Implications for granite petrogenesis on the Moon
- Identification of nanocrystalline goethite in reduced clay formations: Application to the Callovian-Oxfordian formation of Bure (France)
- Dependence of R fluorescence lines of rubies on Cr3+ concentration at various temperatures, with implications for pressure calibrations in experimental apparatus
- Topotactic and reconstructive changes at high pressures and temperatures from Cs-natrolite to Cs-hexacelsian
- High-pressure equation of state and phase transition in PbAl2Si2O8 feldspar
- Enthalpies of formation of rare earth niobates, RE3NbO7
- Weathering of galena: Mineralogical processes, hydrogeochemical fluid path modeling, and estimation of the growth rate of pyromorphite
- Dissolved Cl, oxygen fugacity, and their effects on Fe behavior in a hydrous rhyodacitic melt
- The mobility of Nb in rutile-saturated NaCl- and NaF-bearing aqueous fluids from 1–6.5 GPa and 300–800 °C
- The effect of the [Na/(Na+K)] ratio on Fe speciation in phonolitic glasses
- Technical Note: Calculation of stoichiometry from EMP data for apatite and other phases with mixing on monovalent anion sites
- The effects of immobilized carboxylic-functional groups on the dynamics of phase transformation from amorphous to octacalcium phosphate
- Letter. Structural and chemical characterization of Mg[(Cr,Mg)(Si,Mg)]O4, a new post-spinel phase with sixfold-coordinated silicon
- Letter. Partition of Al between Phase D and Phase H at high pressure: Results from a simultaneous structure refinement of the two phases coexisting in a unique grain
- Letter. The speciation of carbon monoxide in silicate melts and glasses
- Letter. Lightning-induced shock lamellae in quartz
- New Mineral Names
- Book Review
- Errata
