Clay mineral formation under oxidized conditions and implications for paleoenvironments and organic preservation on Mars

Authors

S R. Gainey, University of Nevada, Las VegasFollow
E M. Hausrath, University of Nevada, Las VegasFollow
C T. Adcock, University of Nevada, Las VegasFollow
O Tschauner, University of Nevada, Las VegasFollow
J A. Hurowitz, University of New YorkFollow
B L. Ehlmann, California Institute of Technology
Y Xiao, Carnegie Institution of WashingtonFollow
C L. Bartlett, University of Nevada, Las VegasFollow

Document Type

Article

Publication Date

1-1-2017

Publication Title

Nature Communications

Volume

8

Issue

1

Abstract

Clay mineral-bearing locations have been targeted for martian exploration as potentially habitable environments and as possible repositories for the preservation of organic matter. Although organic matter has been detected at Gale Crater, Mars, its concentrations are lower than expected from meteoritic and indigenous igneous and hydrothermal reduced carbon. We conducted synthesis experiments motivated by the hypothesis that some clay mineral formation may have occurred under oxidized conditions conducive to the destruction of organics. Previous work has suggested that anoxic and/or reducing conditions are needed to synthesize the Fe-rich clay mineral nontronite at low temperatures. In contrast, our experiments demonstrated the rapid formation of Fe-rich clay minerals of variable crystallinity from aqueous Fe3+ with small amounts of aqueous Mg2+. Our results suggest that Fe-rich clay minerals such as nontronite can form rapidly under oxidized conditions, which could help explain low concentrations of organics within some smectite-containing rocks or sediments on Mars. © 2017 The Author(s).

Language

english

Repository Citation

Gainey, S. R., Hausrath, E. M., Adcock, C. T., Tschauner, O., Hurowitz, J. A., Ehlmann, B. L., Xiao, Y., Bartlett, C. L. (2017). Clay mineral formation under oxidized conditions and implications for paleoenvironments and organic preservation on Mars. Nature Communications, 8(1),
http://dx.doi.org/10.1038/s41467-017-01235-7