Publication Date:
2019-07-19
Description:
High Mn concentrations provide unique indicators of water-rich environments and their redox state. Very high-potential oxidants are required to oxidize Mn to insoluble, high-valence oxides that can precipitate and concentrate Mn in rocks and sediments; these redox potentials are much higher than those needed to oxidize Fe or S. Consequently, Mn-rich rocks on Earth closely track the rise of atmospheric oxygen. Given the association between Mn-rich rocks and the redox state of surface environments, observations of anomalous Mn enrichments on Mars raise similar questions about redox history, solubility and aqueous transport, and availability as a metabolic substrate. Our observations suggest that at least some of the high Mn present in Gale crater occurs in the form of Mn-oxides filling veins that crosscut sand-stones, requiring post-depositional precipitation as highly oxidizing fluids moved through the fractured strata after their deposition and lithification.
Keywords:
Chemistry and Materials (General); Lunar and Planetary Science and Exploration
Type:
JSC-CN-32872
,
Lunar and Planetary Science Conference; Mar 16, 2015 - Mar 20, 2015; The Woodlands, TX; United States
Format:
application/pdf
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