Spectroscopy of Loose and Cemented Sulfate-Bearing Soils: Implications for Duricrust on Mars

The composition and evolution of primordial solutions on Mars, with application to other planetary bodies

“…Recent analyses at Gusev Crater and Meridiani Planum (Landis et al, 2004;Rieder et al, 2004) support these findings. There is no data regarding S-or Cspeciation; however the Viking analyses suggest S 6ϩ (Toulmin et al, 1977) and sulfate and carbonate salts have been tentatively identified in the martian dust using infrared spectroscopy (Bell, 1996;Blaney, 2001;Cooper and Mustard, 2002;Bandfield et al, 2003;Christensen et al, 2004). Because sulfate and carbonate salts are relatively soluble (e.g., species derived from salts with small log K in Table 1), any surface solutions in contact with dust must have been a brine such as "dirty water ice" (Christensen, 2003) or a high salinity brine(s) (Brass, 1980).…”

The use of UV‐VIS‐NIR reflectance spectroscopy to identify iron minerals

“…Higher reflection in 416, 473-475 nm indicates free trivalent iron both of terrestrial lab spectra and remote sensed spectra of Martian indurated surface soil (Banin et al 1985;Cooper & Mustard 2002). The reflection in 540-575 nm is also appeared in Martian soil spectra (Esposito, Colangeli & Palomba 2000).…”

Permeability data for impact breccias imply focussed hydrothermal fluid flow

“…This will be dependent upon the concentrations of salts in groundwaters. Evidence from the formation of soil crusts on Mars (Cooper and Mustard, 2002) suggests that reprecipitation of salts is likely in at least some areas.…”