Martian Sulfates as Observed by the Mars Exploration Rover Mössbauer and Alpha Particle X-ray Spectrometers

Details Martian Sulfates as Observed by the Mars Exploration Rover Mössbauer and Alpha Particle X-ray Spectrometers Martian Sulfates as Observed by the Mars Exploration Rover Mössbauer and Alpha Particle X-ray Spectrometers

Dec 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006agufm.p22a..02y&link_type=abstract

American Geophysical Union, Fall Meeting 2006, abstract #P22A-02

Other

1060 Planetary Geochemistry (5405, 5410, 5704, 5709, 6005, 6008), 3672 Planetary Mineralogy And Petrology (5410), 5415 Erosion And Weathering, 6225 Mars

Scientific paper

The Mössbauer and Alpha Particle X-ray Spectrometers (APXS) onboard the Mars Exploration Rovers have returned data from over 200 distinct martian samples. Elemental correlations established using the APXS data provide clear evidence for Mg, Ca, and Fe sulfates. Indications of iron sulfates in the chemical data are shown by the Mössbauer spectrometer to be present in ferric phases. Specific examples include the following: (1) Four localized samples of light-toned, subsurface soils have been imaged by Spirit at Gusev Crater, and two of these exposures have been analyzed in detail using the APXS and Mössbauer Spectrometers. The compositions are highly variable, even over cm-scale distances, but are generally dominated by sulfates and silica. Ferric sulfate (Fe:S ~ 2:3) is the most significant reservoir of the sulfur, though Mg and occasionally Ca sulfates are also present. Associations with hematite, indications of trace element enhancements, and incorporation of chemical signatures of local rocks suggest that these deposits are precipitates from fluids and/or vapors (possibly hydrothermal/fumeraloic). (2) Ca-sulfate (Ca:S ~ 1:1) has been observed in weakly consolidated layered materials in close proximity to light-toned soils described above, providing additional support for an aqueous origin of these deposits. (3) Ca-sulfate is also observed as a cementing agent in a localized occurrence of magnetite-rich sandstones on the northwest flank of the Columbia Hills within Gusev Crater. Ca-sulfate cements may also be present in clastic rocks that dominate the West Spur of the Columbia Hills. (4) The outcrop rocks within Endurance Crater at Meridiani Planum show decreasing amounts of Mg and S with depth and an apparent Mg:S of 1:1, a strong indication of Mg-sulfates. (5) Also within Meridiani outcrop rocks, Ca-sulfates are likely to be present, as the Mg and ferric sulfate (determined to be jarosite by the Mössbauer spectrometer) are inadequate to account for the >20 weight percent SO3. (6) Over 50 analyses of soils by the two rovers show a well-defined correlation between sulfur and chlorine (S:Cl ~ 3.7:1), likely due to surface reactions with volcanic volatiles. Two excavations of subsurface soils on the Gusev plains, however, show an enhancement in S relative to this trend with a corresponding increase in Mg. These Mg-sulfate deposits may be a product of localized aqueous alteration.

Affiliated with

Also associated with

No associations

Rating

Martian Sulfates as Observed by the Mars Exploration Rover Mössbauer and Alpha Particle X-ray Spectrometers 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 Martian Sulfates as Observed by the Mars Exploration Rover Mössbauer and Alpha Particle X-ray Spectrometers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Martian Sulfates as Observed by the Mars Exploration Rover Mössbauer and Alpha Particle X-ray Spectrometers will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-961200