TY - JOUR
T1 - Targeting mixtures of jarosite and clay minerals for Mars exploration
AU - Hinman, Nancy W.
AU - Bishop, Janice L.
AU - Gulick, Virginia C.
AU - Michelle Kotler Dettmann, J.
AU - Morkner, Paige
AU - Berlanga, Genesis
AU - Henneberger, Ruth M.
AU - Bergquist, Peter
AU - Richardson, Charles Doc
AU - Walter, Malcolm R.
AU - MacKenzie, Lindsay A.
AU - Anitori, Roberto P.
AU - Scott, Jill R.
N1 - Funding Information:
R.M.H. was funded by Macquarie University (Postgraduate Research Fund and an International Travel Scholarship). N.W.H., J.R.S., C.D.R., and J.M.K. were funded by the National Aeronautics and Space Administration (NASA) Exobiology Program (Grant No. NNX08AP59G). N.W.H., V.C.G., and J.L.B. received funding from the NASA Astrobiology Institute (Grant No. NNX15BB01A, N. Cabrol, PI). J.L.B. also received support from the NASA MDAP program (Grant No. NSSC19K1230). P.M. was a NASA Intern at NASA ARC, funded by the California Space Grant under the mentorship of V.C.G. G.B. was a NASA Graduate Student Intern at NASA ARC, funded by the USRA under the mentorship of V.C.G. V.C.G., P.M., and G.B. thank Job Bello (Spectra Solutions, Inc.) for the dual excitation probe EIC Raman Instrument. N.W.H. thanks Gretchen Grimes for assistance. Research was performed at the Idaho National Laboratory under DOE Idaho Operations Office Contract DE-AC07-05ID14517. Research in Yellowstone National Park was conducted under research permit YELL-SCI-1660.
Publisher Copyright:
© 2021 Walter de Gruyter GmbH, Berlin/Boston 2021.
PY - 2021/8/26
Y1 - 2021/8/26
N2 - Terrestrial thermal environments can serve as analogs for subsurface environments in the search for life because they regularly host microbial communities, which may leave behind biosignatures. This study focused on an acid-sulfate hydrothermal site as an analog for a potentially habitable environment on Mars. A weathered boulder in the thermal area was dissected, revealing an interior marked with disconnected horizons of differently colored materials, very low pH, and increasing temperature. The mineralogy comprised weathering products from andesite (kaolinite, quartz, clinoptilolite) along with sulfate salts (alunite, jarosite, tschermigite, and copiapite) formed by oxidation of sulfide and ferrous iron. Characterization of organic matter in this boulder and several soil samples yielded interesting but surprising results. Both mass spectrometry and Raman spectroscopy identified organic compounds in portions of the soils and the boulder. Jarosite-associated samples showed more numerous and diverse organic signatures than did Al-bearing silicate samples, despite the lower total organic carbon content of the jarosite-associated soils (0.69 ± 0.07 wt% Corg) compared to the Al-bearing samples (1.28 ± 0.13 wt% Corg). Results from our geochemical, mineralogical, and spectroscopic study of hydrothermal alteration products and salts inform the heterogeneous distribution of inorganic and organic materials that could delineate habitats and demonstrate the limits on organic matter detectability using different analytical techniques. Furthermore, we relate our measurements and results directly to current and upcoming martian missions, and we provide recommendations for detection and characterization of minerals and organics as biosignatures on Mars using instruments on future missions.
AB - Terrestrial thermal environments can serve as analogs for subsurface environments in the search for life because they regularly host microbial communities, which may leave behind biosignatures. This study focused on an acid-sulfate hydrothermal site as an analog for a potentially habitable environment on Mars. A weathered boulder in the thermal area was dissected, revealing an interior marked with disconnected horizons of differently colored materials, very low pH, and increasing temperature. The mineralogy comprised weathering products from andesite (kaolinite, quartz, clinoptilolite) along with sulfate salts (alunite, jarosite, tschermigite, and copiapite) formed by oxidation of sulfide and ferrous iron. Characterization of organic matter in this boulder and several soil samples yielded interesting but surprising results. Both mass spectrometry and Raman spectroscopy identified organic compounds in portions of the soils and the boulder. Jarosite-associated samples showed more numerous and diverse organic signatures than did Al-bearing silicate samples, despite the lower total organic carbon content of the jarosite-associated soils (0.69 ± 0.07 wt% Corg) compared to the Al-bearing samples (1.28 ± 0.13 wt% Corg). Results from our geochemical, mineralogical, and spectroscopic study of hydrothermal alteration products and salts inform the heterogeneous distribution of inorganic and organic materials that could delineate habitats and demonstrate the limits on organic matter detectability using different analytical techniques. Furthermore, we relate our measurements and results directly to current and upcoming martian missions, and we provide recommendations for detection and characterization of minerals and organics as biosignatures on Mars using instruments on future missions.
KW - Earth Analogs for Martian Geological Materials and Processes
KW - Mars
KW - astrobiology
KW - exobiology
KW - spectroscopy
KW - surface
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UR - http://www.scopus.com/inward/citedby.url?scp=85112438086&partnerID=8YFLogxK
U2 - 10.2138/am-2021-7415
DO - 10.2138/am-2021-7415
M3 - Article
AN - SCOPUS:85112438086
SN - 0003-004X
VL - 106
SP - 1237
EP - 1254
JO - American Mineralogist
JF - American Mineralogist
IS - 8
ER -