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Abundances and implications of volatile‐bearing species from evolved gas analysis of the Rocknest aeolian deposit, Gale Crater, Mars
Author(s) -
Archer Paul Douglas,
Franz Heather B.,
Sutter Brad,
Arevalo Ricardo D.,
Coll Patrice,
Eigenbrode Jennifer L.,
Glavin Daniel P.,
Jones John J.,
Leshin Laurie A.,
Mahaffy Paul R.,
McAdam Amy C.,
McKay Christopher P.,
Ming Douglas W.,
Morris Richard V.,
NavarroGonzález Rafael,
Niles Paul B.,
Pavlov Alex,
Squyres Steven W.,
Stern Jennifer C.,
Steele Andrew,
Wray James J.
Publication year - 2014
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
eISSN - 2169-9100
pISSN - 2169-9097
DOI - 10.1002/2013je004493
Subject(s) - mars exploration program , aeolian processes , astrobiology , atmosphere of mars , weathering , martian surface , impact crater , perchlorate , geology , mineralogy , martian , environmental chemistry , chemistry , geochemistry , geomorphology , organic chemistry , ion , physics
The Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) rover Curiosity detected evolved gases during thermal analysis of soil samples from the Rocknest aeolian deposit in Gale Crater. Major species detected (in order of decreasing molar abundance) were H 2 O, SO 2 , CO 2 , and O 2 , all at the µmol level, with HCl, H 2 S, NH 3 , NO, and HCN present at the tens to hundreds of nmol level. We compute weight % numbers for the major gases evolved by assuming a likely source and calculate abundances between 0.5 and 3 wt.%. The evolution of these gases implies the presence of both oxidized (perchlorates) and reduced (sulfides or H‐bearing) species as well as minerals formed under alkaline (carbonates) and possibly acidic (sulfates) conditions. Possible source phases in the Rocknest material are hydrated amorphous material, minor clay minerals, and hydrated perchlorate salts (all potential H 2 O sources), carbonates (CO 2 ), perchlorates (O 2 and HCl), and potential N‐bearing materials (e.g., Martian nitrates, terrestrial or Martian nitrogenated organics, ammonium salts) that evolve NH 3 , NO, and/or HCN. We conclude that Rocknest materials are a physical mixture in chemical disequilibrium, consistent with aeolian mixing, and that although weathering is not extensive, it may be ongoing even under current Martian surface conditions.