Sulfates in Martian Layered Terrains: The OMEGA/Mars Express View

J.-P. Bibring et al., European Space Agency Spec. Publ.1240, 37 (2004).

J.-P. Bibring et al., Science307, 1576 (2005); published online 17 February 2005.

J. F. Mustard et al., Science307, 1594 (2005); published online 17 February 2005.

R. N. Clark et al., J. Geophys. Res.95, 12653 (1990).

Band positions are given with an accuracy of 0.1 μm when the absorption bands are broad or their center is in a wavelength range with possible atmospheric residuals, or in a wavelength range with possible remaining instrumental effects. Otherwise, positions are given with an accuracy of 0.01 μm.

J. K. Crowley et al., Geochem. Explor. Environ. Anal.3, 219 (2003).

Y. Langevin et al., Science307, 1584 (2005); published online 17 February 2005.

M. Lane et al., Geophys. Res. Lett.31, L19702 (2004).

The sulfates are identified with the use of band ratios. To map the sulfate areas, we used a methodology based on (28). We then checked that each spectrum of the resulting classification presents the absorption bands of interest.

J. F. McCauley et al., Icarus17, 289 (1972).

B. K. Lucchitta et al., NASA Tech. Memo.85127, 233 (1982).

B. K. Lucchitta et al., J. Geophys. Res.99, 3783 (1994).

S. S. Nedell et al., Icarus70, 409 (1987).

M. C. Malin, K. S. Edgett, Science290, 1927 (2000).

M. G. Chapman, K. L. Tanaka, Icarus155, 324 (2002).

R. E. Arvidson et al., J. Geophys. Res.108, ROV 14-1 (2003).

B. M. Hynek, Nature431, 156 (2004).

D. T. Vaniman et al., Nature431, 663 (2004).

A. Banin et al., J. Geophys. Res.102, 13341 (1997).

J. Warren, Evaporites: Their Evolution and Economics (Blackwell Science, Oxford, UK, 1999).

Kieserite forms at temperatures typically higher than 40°C, whereas more hydrated phases such as epsomite form at lower temperatures. The association of these minerals of different hydration levels is common on Earth because of diurnal or seasonal temperature variations. Ions and cations present in the body of water control the sequence of formation of evaporitic minerals. The classic terrestrial sequence is dominated by large proportions of halite with underlying gypsum and minor deposits of carbonates at the base. Kieserite and other K or Mg salts are minor components appearing at the top of the sequence. We can outline the large accumulation of kieserite of the Zechstein basin of the Permian epoch and the deposition of magnesium sulfates in the currently drying Aral Sea.

M. A. Bullock et al., Icarus170, 404 (2004).

D. C. Catling, J. Geophys. Res.104, 16453 (1999).

A. G. Fairen et al., Nature431, 423 (2004).

S. W. Squyres et al., Science306, 1698 (2004).

D. L. Huston et al., Earth Planet. Sci. Lett.220, 41 (2004).

R. E. Arvidson et al., Science307, 1591 (2005); published online 17 February 2005.

Green et al., IEEE Trans. Geosc. Rem. Sens.26, 65 (1993).

G. R. Hunt et al., Mod. Geol.3, 1 (1971).

J. Bishop, E. Murad, Am. Miner., in press.

Laboratory reflectance data provided through a cooperation with NASA and the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) team. Reflectance measurements were acquired at the Reflectance Experiment Laboratory (RELAB) at Brown University. Efforts to acquire these data by J. F. Mustard are gratefully acknowledged.