Revealing High‐Manganese Material on Mars at Microscale

Abstract

Manganese (Mn) is a redox-sensitive element. It commonly occurs as Mn(II) (substituting for Fe 2+ ) in a wide range of primary igneous minerals (e.g., olivine and pyroxene). On Earth, when igneous rocks interact with surface water or groundwater, Mn is readily depleted from the host rock and becomes mobile, as Mn(II), in aqueous systems (Crerar et al., 1980). To precipitate and concentrate Mn, the reduced Mn 2+ needs to be oxidized by high-potential oxidants (much higher than that for Fe or S, e.g., O 2 ) in liquid water to form insoluble high-valence Mn-oxides (e.g.,

On the Diversity and Formation Modes of Martian Minerals

“…Note that Cu and Ni are known only from sulfides in martian meteorites, while Ba and Sr are inferred from the sulfate minerals, baryte and celestine. Mn minerals are present but are not yet represented by a confirmed mineral species (Lanza et al., 2016, 2021; Zeng et al., 2021). We discount reports based on spectral data (Rice et al., 2010) of the boron‐bearing mineral datolite, a phase difficult to justify from a paragenetic perspective.…”

Mn‐Precipitates Found in a Martian Crustal Rock

“…Intrinsic Mn 4+ O 2 mineral has been identified in the Martian regolith breccias Northwest Africa (NWA) 7034, 7533, and 11220 (Liu et al., 2021; Zeng et al., 2021). These Mn‐precipitates are formed by the oxidation of Mn 2+ leached from surface rocks by weathering (Liu et al., 2021; Noda et al., 2019; Zeng et al., 2021). If Mn‐precipitates in Y 000802 formed near the surface of Mars, the dominant phase would be Mn 4+ O 2 mineral, similar to Mn‐precipitates in rocks from Endeavour and Gale craters and regolith breccias.…”

“…It has been inferred that the Mn 2+ was oxidized in the Martian atmosphere and precipitated as Mn 4+ O 2 minerals (Noda et al., 2019). This assumption is supported by the discovery of Mn 4+ O 2 minerals from Martian breccia meteorites, which are similar to Martian surface rocks (Agee et al., 2013; Liu et al., 2021; Zeng et al., 2021).…”

“…Mn-precipitates are found in rocks from Endeavour and Gale craters, Mars (Arvidson et al, 2016;Lanza et al, 2014Lanza et al, , 2016 and are thought to be Mn 4+ O 2 mineral based on the laboratory precipitation experiments of manganese (Noda et al, 2019). Intrinsic Mn 4+ O 2 mineral has been identified in the Martian regolith breccias Northwest Africa (NWA) 7034, 7533, and 11220 (Liu et al, 2021;Zeng et al, 2021). These Mn-precipitates are formed by the oxidation of Mn 2+ leached from surface rocks by weathering (Liu et al, 2021;Noda et al, 2019;Zeng et al, 2021).…”

“…A trace amount of Mn 4+ mineral is present in the Mn-precipitates of Y 000802, suggesting that some of the Mn 2+/3+ minerals were oxidized. Mn 4+ mineral is dominant in the fracture-fillings of rocks from Endeavour and Gale craters (Arvidson et al, 2016;Lanza et al, 2014Lanza et al, , 2016Noda et al, 2019) and the Martian regolith breccias (Liu et al, 2021;Zeng et al, 2021). In these previous studies, the candidate oxidant for the formation of Mn 4+ mineral is molecular oxygen (O 2 ).…”