Data for: FTIR Constraints on Martian Mantle Water from Clinopyroxene in Nakhlite and Shergottite Meteorites. (Radu et al.)

This dataset contains raw data tables associated with a study investigating the water content of pyroxenes from nakhlites and shergottites, using FTIR analyses and hydrothermal rehydration experiments. The central hypothesis is that hydrogen-associated structural defects in pyroxene, which are preserved after dehydration, can be experimentally rehydrated to reconstruct the original water content of the pyroxene crystals. This further allows estimating the water content of the melt from which the pyroxenes crystallised.
The data include Fourier Transform Infrared Spectroscopy acquired untreated, after H2-gas treatment, and after H2O-treatment, major element compositions acquired by Scanning Electron Microscope, Supplementary material summarising average major element composition in oxide weight percent and as atoms per formula unit, Table 1. Summary of sample provenance, classification, and measured water content, Table 2. Magmatic water contents calculated using the equation of O'Leary et al. (2010), measured post-hydrothermal water contents, and pyroxene composition for the nakhlites, Table 3. Recalculated water contents of shergottite pyroxenes using the equation of O'Leary et al. (2010) and published estimates of shergottite magmatic water contents (McCubbin et al., 2016; Usui et al., 2012), literature compilation of mantle water estimates for various reservoirs for comparison
The treated nakhlite augites record water contents of 140‒186 ppm H2O, corresponding to magmatic water contents of 1.59‒1.82 wt% H2O and a mantle source estimate of 76‒91 ppm H2O, consistent with previous estimates and supportive of a common magmatic source for all nakhlites. No measurable water was detected in the shergottite pyroxenes, consistent with their expected low water contents of 2‒11 ppm. The water estimates for the nakhlites should be regarded as minimum values, given evidence for magmatic degassing and interaction with H2O-poor Cl-rich fluids in the nakhlite magmatic system. Full methodological details and interpretation are provided in the associated publication.