Publication Type Journal Article
Title Analysis of mineral matrices of planetary soil analogues from the Utah Desert
Authors J. M. Kotler R. C. Quinn B. H. Foing Zita Martins P. Ehrenfreund
Groups
Journal INTERNATIONAL JOURNAL OF ASTROBIOLOGY
Year 2011
Month July
Volume 10
Number 3
Pages 221-229
Abstract Phyllosilicate minerals and hydrated sulphate minerals have been positively identified on the surface of Mars. Studies conducted on Earth indicate that micro-organisms influence various geochemical and mineralogical transitions for the sulphate and phyllosilicate minerals. These minerals in turn provide key nutrients to micro-organisms and influence microbial ecology. Therefore, the presence of these minerals in astrobiology studies of Earth-Mars analogue environments could help scientists better understand the types and potential abundance of micro-organisms and/or biosignatures that may be encountered on Mars. Bulk X-ray diffraction of samples collected during the EuroGeoMars 2009 campaign from the Mancos Shale, the Morrison and the Dakota formations near the Mars Desert Research Station in Utah show variable but common sedimentary mineralogy with all samples containing quantities of hydrated sulphate minerals and/or phyllosilicates. Analysis of the clay fractions indicate that the phyllosilicates are interstratified illitesmectites with all samples showing marked changes in the diffraction pattern after ethylene glycol treatment and the characteristic appearance of a solvated peak at similar to 17 angstrom. The smectite phases were identified as montmorillonite and nontronite using a combination of the X-ray diffraction data and Fourier-Transform Infrared Spectroscopy. The most common sulphate mineral in the samples is hydrated calcium sulphate (gypsum), although one sample contained detectable amounts of strontium sulphate (celestine). Carbonates detected in the samples are variable in composition and include pure calcium carbonate (calcite), magnesium-bearing calcium carbonate (dolomite), magnesium, iron and manganese-bearing calcium carbonate (ankerite) and iron carbonate (siderite). The results of these analyses when combined with organic extractions and biological analysis should help astrobiologists and planetary geologists better understand the potential relationships between mineralogy and microbiology for planetary missions.
DOI http://dx.doi.org/10.1017/S1473550411000103
ISBN
Publisher
Book Title
ISSN 1473-5504
EISSN
Conference Name
Bibtex ID ISI:000291609600007
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