TY - JOUR

T1 - Platinum solubility in a haplobasaltic melt at 1250°C and 0.2 GPa

T2 - The effect of water content and oxygen fugacity

AU - Blaine, Fred A.

AU - Linnen, Robert L.

AU - Holtz, Francois

AU - Brügmann, Gerhard E.

N1 - Funding Information: This project was supported by the “Hochschulvergabe Projekt N° 75 of the BGR (German Geological Survey), by the DFG (German Science Foundation, project Ho 1337/9), and by NSERC and PREA awards to R.L.L. The authors wish to thank M. Sierralta, J. Berndt, M. Freise, and O. Diedrich for their technical and scientific assistance and K. Burgath and F. Melcher (BGR) for helpful discussions when the project was initiated. The authors would also like to thank everyone at the Institut für Mineralogie, Universität Hannover for their assistance. We would also like to thank Hans Keppler and A. E. William Jones for their helpful reviews. Copyright: Copyright 2011 Elsevier B.V., All rights reserved.

PY - 2005/3/1

Y1 - 2005/3/1

N2 - Haplobasaltic melts with a 101 kPa dry eutectic composition (An42Di58) and varying water contents were equilibrated with their platinum capsule at 1523 K and 200 MPa in an internally heated pressure vessel (IHPV) equipped with a rapid quench device. Experimental products were inclusion-free glasses representative of the Pt-saturated silicate melts at the experimental conditions. Platinum concentrations were determined using an isotope dilution multicollector inductively coupled plasma mass spectrometer and water contents and distribution by Karl Fischer titration and Fourier transform infrared spectroscopy, respectively. The water content of the melt has no intrinsic effect on platinum solubility, for concentrations between 0.9 wt.% and 4.4 wt.% H2O (saturation). Platinum solubility increases with increasing water content, but this effect is an indirect effect because increasing water content at fixed fH2 (imposed by the IHPV) increases the oxygen fugacity of the experiment. The positive oxygen fugacity dependence of Pt solubility in a hydrous silicate melt at 200 MPa is identical to that in anhydrous melts of the same composition determined in previous studies at 101 kPa. This study extends the range of platinum solubilities to oxygen fugacities lower than was previously possible. Combining the data of this and previous studies, Pt solubility is related to oxygen fugacity (in bar) at 1523 K by the equation: [Pt]total(ppb) = 1389 × fO2 + 7531 × (fO2)1/2.

AB - Haplobasaltic melts with a 101 kPa dry eutectic composition (An42Di58) and varying water contents were equilibrated with their platinum capsule at 1523 K and 200 MPa in an internally heated pressure vessel (IHPV) equipped with a rapid quench device. Experimental products were inclusion-free glasses representative of the Pt-saturated silicate melts at the experimental conditions. Platinum concentrations were determined using an isotope dilution multicollector inductively coupled plasma mass spectrometer and water contents and distribution by Karl Fischer titration and Fourier transform infrared spectroscopy, respectively. The water content of the melt has no intrinsic effect on platinum solubility, for concentrations between 0.9 wt.% and 4.4 wt.% H2O (saturation). Platinum solubility increases with increasing water content, but this effect is an indirect effect because increasing water content at fixed fH2 (imposed by the IHPV) increases the oxygen fugacity of the experiment. The positive oxygen fugacity dependence of Pt solubility in a hydrous silicate melt at 200 MPa is identical to that in anhydrous melts of the same composition determined in previous studies at 101 kPa. This study extends the range of platinum solubilities to oxygen fugacities lower than was previously possible. Combining the data of this and previous studies, Pt solubility is related to oxygen fugacity (in bar) at 1523 K by the equation: [Pt]total(ppb) = 1389 × fO2 + 7531 × (fO2)1/2.

UR - http://www.scopus.com/inward/record.url?scp=14844307125&partnerID=8YFLogxK

U2 - 10.1016/j.gca.2004.08.008

DO - 10.1016/j.gca.2004.08.008

M3 - Article

AN - SCOPUS:14844307125

VL - 69

SP - 1265

EP - 1273

JO - Geochimica et Cosmochimica Acta

JF - Geochimica et Cosmochimica Acta

SN - 0016-7037

IS - 5

ER -