Fig. 4: ∂D versus H2O for heated and unheated omphacite Obn112.
From: Molecular hydrogen in minerals as a clue to interpret ∂D variations in the mantle
Total water content (determined by Thermal conversion/Elemental Analyser coupled with Isotope-Ratio Mass spectrometer - TC/EA-IRMS) and ∂D (relative to Vienna Standard Mean Ocean Water – V-SMOW) show a robust linear correlation. The loss of H with increasing temperature implies higher ∂D values supporting the loss of a component with much more negative ∂D (thus H2 rather than OH or H2O), as also observed in the infra-red spectra where the integrated absorbance of the H2 band decreases significantly with increasing temperature.
