Analysis of hydrogen and fluorine in pyroxenes by SIMS and FTIR: 

Part I. Orthopyroxene

Jed L. Mosenfelder, George R. Rossman
Division of Geological and Planetary Sciences
California Institute of Technology
Pasadena, CA  91125-2500


We measured trace concentrations of hydrogen (~40-400 ppm H2O) and fluorine (<1 to 17 ppm) in a suite of nine orthopyroxenes from varying geological environments, using secondary ion mass spectrometry (SIMS) and Fourier transform infrared (FTIR) spectroscopy. The hydrogen data are considered with reference to both the manometry based calibration of Bell et al. (1995) and the frequency dependent calibration for the absorption coefficient derived by Libowitzky and Rossman (1997). Despite the fact that our samples exhibit a wide range of IR band structures, with varying percentages of absorbance split among low (2600-3350 cm-1) and high (3350-3700 cm-1) wavenumber bands, our SIMS data are fit with the same precision and virtually the same regression slope regardless of which IR calibration is used. We also confirm previous suggestions that the matrix effect for SIMS analyses between orthopyroxene and olivine is small (≤20%). Anomalously high yields of 16O1H in some analyses can be attributed to the presence of amphibole lamellae, and these analyses must be filtered out with different criteria than for olivine due to differences in the geometrical relationship of host to inclusion. For fluorine, our derived values are highly dependent on a number of analytical uncertainties related to the use of silicate glasses as standards. Regardless of the accuracy of our calibration, we see systematic differences in fluorine concentrations in orthopyroxenes and olivines depending on their geological context. Samples derived from crustal environments and from Colorado Plateau minette diatremes have very low fluorine (≤3 ppm), while higher contents (up to 17 ppm in orthopyroxene and 47 ppm in olivine) can be found in megacrysts from South African kimberlites. 

Raw Data: orthopyroxene samples:

IR Spectra (Microsoft Excel files with alpha, beta and gamma spectra):

All FTIR spectra in one file
DE 2-1
GK opx A
GRR 1650b
GRR 2334a
JLM 46
JLM 50
PRM 54

Appendices: SIMS analyses and calibration data (Microsoft Excel files):

All SIMS data in one file
Table 1: SIMS glass analyses
Table 2: SIMS orthopyroxene analyses
Table 3: SIMS olivine analyses

Last updated 30-Jan-2014