Modal Mineralogy of the Martian Phyllosilicate-rich Terrains from the Mex/omega Reflectance Data

Details Modal Mineralogy of the Martian Phyllosilicate-rich Terrains from the Mex/omega Reflectance Data Modal Mineralogy of the Martian Phyllosilicate-rich Terrains from the Mex/omega Reflectance Data

Oct 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007dps....39.1405p&link_type=abstract

American Astronomical Society, DPS meeting #39, #14.05; Bulletin of the American Astronomical Society, Vol. 39, p.435

Mathematics

Logic

Scientific paper

Using classical methods of spectral identification based on the absorption band depth of minerals, OMEGA has provided an unambiguous identification of phyllosilicates on the surface of Mars (Poulet et al. 2005, Nature, 438). The presence of these minerals on Mars is of great exobiological relevance, because some of phyllosilicates are potential prebiotic catalyst. However, one of the significant challenges for the use of reflectance spectroscopy is the relationships between the band depth absorptions and mineral abundances and grain sizes.
The modal mineralogy (mineral abundances) of the phyllosilicate-rich terrains is derived using a nonlinear unmixing model based on the Shkuratov radiative transfer theory (Shkuratov et al. 1999, Icarus, 137). We focus our study on the two major regions where phyllosilicates were detected on Mars: Mawrth Vallis and Nilo-Syrtis. Significant differences between these two regions in mineral abundances are found. The phyllosilicate-rich outcrops in Mawrth Vallis are best reproduced by 60% of phyllosilicates (nontronite, montmorillonite) mixed with hydroxides (Ferrihydrite as a likely end-member) and some non-phyllosilicate materials (plagioclase and Martian dust). In the NiloSyrtis region, the total abundance of the phyllosilicate minerals is significantly smaller than in Mawrth Vallis and mafic materials such as pyroxene are always required. This strongly suggests that the degree of alteration was stronger in Mawrth Vallis than anywhere on Mars. In the NiloSyrtis region, we observe significant spot-to-spot differences in modal mineralogy; these differences are remarkably consistent with the geomorphology. For instance, the floor of a crater is well reproduced by a mixture containing a low grade metamorphic water-bearing mineral. This unique mineralogy suggests that the impact may have played a role in the formation of this secondary mineral. Other implications for surface alteration will be addressed.

Affiliated with

Also associated with

No associations

Rating

Modal Mineralogy of the Martian Phyllosilicate-rich Terrains from the Mex/omega Reflectance Data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Modal Mineralogy of the Martian Phyllosilicate-rich Terrains from the Mex/omega Reflectance Data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Modal Mineralogy of the Martian Phyllosilicate-rich Terrains from the Mex/omega Reflectance Data will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1065167