HR: 13:55h
AN: P12C-02 INVITED     [PDF]
TI: Mars Surface Composition Through Pan-spectral Analysis: Mafic Mineralogy, Alteration, and Hydration
AU: * Mustard, J F
EM: John_Mustard@brown.edu
AF: Department of Geological Sciences, Box 1846, Brown University, Providence, RI 02912 United States
AB: In the next five years there will be global data sets for Mars spanning the wavelength range 0.4-50 microns encompassing the reflected solar and emitted thermal regimes (pan-spectral). These data sets provide critical information on surface mineralogy and composition. The reflected solar region is most sensitive to electronic processes associated with iron minerals (e.g. ferric oxides, mafic silicates) and vibrational processes associated with hydroxyl, water, and other anions. The emitted thermal region is sensitive to the lattice mode vibrations of minerals. Thus these regions are extremely complementary in the specific information provided,. While laboratory measurements have been used to investigate the pan-spectral properties of materials, we have just completed a study of the pan-spectral properties of the martian surface using spacecraft observations. We merged data from the spatially-limited ISM experiment that flew on the Phobos-II mission in 1989 with thermal emission observations from the TES experiment with arrived at Mars in 1998. Our strategy was to test hypotheses developed through the analysis of ISM data (electronic and vibrational spectroscopic interpretations) with TES data (lattice-mode interpretations). The key areas of investigation are the composition of dark regions, mineralogic interpretations of unique materials on the floor of Eos Chasma, variations in spectral properties across Syrtis Major, and the mineralogy of hydrated deposits typical of dark red regions. Dark region mineralogies are complementary and consistent using pan-spectral analysis, though differences remain on the nature of the pyroxene composition. The materials on the floor of Eos Chasma are apparently more pyroxene rich than typical dark materials. The variations in visible and infrared spectral properties across Syrtis Major are most consistent with penetrative oxidation rather than surface coatings. And the mineralogy of dark red regions is consistent with a sulfate-cemented dust. The results indicate that with new global visible-infrared data sets to complement the existing global thermal infrared data, a highly refined picture of martian surface composition will emerge.
DE: 5410 Composition
DE: 5464 Remote sensing
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting