Open AccessHydroxide in olivine: A quantitative determination of the absolute amount and calibration of the IR spectrum
Author(s) -
Bell David R.,
Rossman George R.,
Maldener Joachim,
Endisch Denis,
Rauch Friedel
Publication year - 2003
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2001jb000679
Subject(s) - olivine , mantle (geology) , hydrogen , absorbance , analytical chemistry (journal) , mineralogy , calibration , infrared spectroscopy , hydroxide , geology , spectral line , infrared , chemistry , geochemistry , physics , inorganic chemistry , optics , environmental chemistry , organic chemistry , chromatography , quantum mechanics , astronomy
Olivine is an important host of hydrogen in the Earth's upper mantle, and the OH abundance in this mineral determines many important physical properties of the planet's interior. To date, natural and experimentally hydrated olivines have been analyzed by uncalibrated spectroscopic methods with large (±100%) uncertainties in accuracy. We determined the hydrogen contents of three natural olivines by 15 N nuclear reaction analysis and used the results to calibrate the common infrared (IR) spectroscopic method for quantitative hydrogen analysis of olivine. OH content (expressed as parts per million H 2 O by weight) is 0.188 times the total integrated absorbance of the fundamental OH stretching bands in the 3750–3100 cm −1 region. The results indicate that an upward revision of some previous determinations by factors of between 2 and 4 is necessary. The most hydrous naturally occurring mantle‐derived olivine analyzed to date contains 240 ppm wt. H 2 O. Retrospective application of this calibration to experimentally hydrated olivines may be limited by spectral differences in some cases and by the previous use of nonpolarized IR spectra.