Spectral identification of hydrated sulfates on Mars and comparison with acidic environments on Earth

Abstract

We interpret recent spectral data of Mars collected by the Mars Exploration Rovers to contain substantial evidence of sulfate minerals and aqueous processes. We present visible/near-infrared (VNIR), mid-IR and Mössbauer spectra of several iron sulfate minerals and two acid mine drainage (AMD) samples collected from the Iron Mountain site and compare these combined data to the recent spectra of Mars. We suggest that the sulfates on Mars are produced via aqueous oxidation of sulfides known to be present on

Modeling ferrous–ferric iron chemistry with application to martian surface geochemistry

“…On Mars today, there is abundant evidence for iron minerals such as hematite, goethite, and jarosites (Christensen et al, 2001Bandfield, 2002;Bishop et al, 2004;Klingelhö fer et al, 2004;Morris et al, 2004Morris et al, , 2006Squyres et al, 2004Squyres et al, , 2006Clark et al, 2005;Golden et al, 2005;Navrotsky et al, 2005;Tosca et al, 2005;Ming et al, 2006). If one is looking for other secondary iron minerals on Mars, strong candidates include lepidocrocite, schwertmannite, ferricopiapite, copiapite, and bilinite (Table 8).…”

Acid Rivers and Lakes at Caviahue-Copahue Volcano as Potential Terrestrial Analogues for Aqueous Paleo-Environments on Mars

“…Martian sulfates are associated with a number of non-igneous minerals including alunite, anhydrite, goethite, hematite and kaolinite (e.g., Ehlmann and Edwards 2014). Formation of all these minerals requires specific conditions, for example jarosite needs sulfate rich, acidic (pH < 4.0) and oxidizing conditions to form (Stoffregen 1993;Stoffregen et al 2000) and the specific environment for each mineral is reasonably well known from theory and terrestrial occurrences (Bishop et al 2005;Papike et al 2006). In this chapter, the possibility to interpret active acid hydrothermal systems with their crater lakes, rivers and ponds as found at Copahue volcano as terrestrial analogues for some of these early Mars environments that formed sulfates (e.g., Oonk 2013), was evaluated.…”

Modeling aluminum–silicon chemistries and application to Australian acidic playa lakes as analogues for Mars

“…Alternative mechanisms for acidification include pyrite oxidation (Long et al, 1992a,b;Bishop et al, 2003Bishop et al, , 2004Zolotov and Shock, 2005), ferrolysis (McArthur et al, 1991;Long et al, 1992a,b;Papike et al, 2006), and acidic volatiles emitted by volcanoes (Banin et al, 1997;McCollom and Hynek, 2005). Earth analogues for Meridiani Planum surface geochemistries include: (1) acid mine drainages (AMD) (Fernandez-Remolar et al, 2003Bishop et al, 2004), (2) Antarctic deserts (Wierzchos and Ascaso, 2002;Bishop et al, 2003;Kreslavsky and Head, 2008), and (3) acidic saline lakes (Benison and LaClair, 2003;Benison and Bowen, 2006;Benison et al, 2007;Bowen and Benison, 2008). Potential geochemistries of Meridiani Planum have also been explored using laboratory studies (Banin et al, 1997;Tosca et al, 2004;Golden et al, 2005) and modeling (Schaefer 1990(Schaefer , 1993Morse and Marion, 1999;King et al, 2004;Marion and Kargel, 2008;Marion et al, 2008b).…”