Other
Scientific paper
May 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005gecoa..69.2333s&link_type=abstract
Geochimica et Cosmochimica Acta, Volume 69, Issue 9, p. 2333-2348.
Other
12
Scientific paper
A new microscale oxybarometer for solar system basaltic glasses, based on vanadium K-edge X-ray absorption near edge structure (XANES) spectroscopy, is described. Vanadium is unique among abundant elements in siliceous materials in that it can potentially occur in nature in four valence states: V2+, V3+, V4+ and V5+. Consequently, the vanadium redox system is a robust oxybarometer covering at least six orders of magnitude in buffer-relative oxygen fugacity. The method was calibrated using synthetic glass standards produced under known fO2 and temperature conditions. Correction for temperature differences among standards and unknowns was quantified using microXANES data for isobaric synthetic glass couples. Application of the method to lunar, martian, and terrestrial glasses yielded fO2 estimates from 1.6 log units more reduced than the iron-wüstite (IW) buffer (IW-1.6) for lunar glasses, to IW + 4.0 for terrestrial glass inclusions. The martian and terrestrial results are in good agreement with previous estimates by other methods. The inferred fO2 values for lunar pyroclastic glasses are ˜0.5 log unit more reduced than previous estimates, but the differences are comparable to analytical uncertainties. Micro-extended X-ray absorption fine structure spectra were consistent with the valence states determined by microXANES and provided additional constraints on vanadium site geometry. These results demonstrate the value of this new oxybarometer, which can be applied nondestructively to individual grains in conventional thin sections with ˜ micrometer resolution and ˜100 ppm elemental sensitivity.
Darby Dyar M.
Delaney Jeremy S.
Eng Peter
Karner J.
Newville Matthew
No associations
LandOfFree
Vanadium K edge XANES of synthetic and natural basaltic glasses and application to microscale oxygen barometry does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Vanadium K edge XANES of synthetic and natural basaltic glasses and application to microscale oxygen barometry, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vanadium K edge XANES of synthetic and natural basaltic glasses and application to microscale oxygen barometry will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1434708