Hydrogen Isotope Fractionation During Impact Degassing of Pyroxene and Maskelynite in Shergottite Larkman Nunatak 06319Hydrogen in nominally anhydrous minerals (NAMs) in meteorites provides insight to mantle sources of indigenous water on differentiated bodies: e.g. Peslier et al. 2017 [1], including Mars [2-4]. However, all meteorite samples, including Martian shergottites, record impact events as fractures, deformation, silicate darkening, shock melt veins and pockets, etc. The effect of shock on hydrogen in NAMs is poorly constrained, and must be understood prior to using these data to infer planetary indigenous water. Here we present water contents and D/H ratios (calculated as dD, i.e. the variation of the D/H ratio relative to a standard, in this case sea water "SMOW") in pyroxene, olivine and maskelynite in the olivine-phyric shergottite Larkman Nunatak 06319 (LAR 06319) as a function of proximity to impact melt. While the results suggest impact may have a role in fractionating H isotopes, the magmatic signature of H2O in Mars can be preserved in some pyroxene.
Document ID
20190001953
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Dudley, J. M. (Jacobs Technology, Inc. Houston, TX, United States)
Peslier, A. H. (Jacobs Technology, Inc. Houston, TX, United States)
Herving, R. L. (Arizona State Univ. Flagstaff, AZ, United States)