Voluminous Silica Precipitated from Martian Waters during Late-stage Aqueous Alteration

Martian and Lunar Meteorites: Styles of Aqueous Alteration

Introduction: With the recent return of remote sensing evidence for aqueous alteration on Mars in the form of evaporates and other secondary minerals (MERs [e.g., 1] and Mars Express [e.g., 2]), understanding the differences between weathering processes on Mars and Earth becomes imperative. Martian meteorites provide the only available source of detailed geochemical analyses of Martian material...

The toxicity of precipitated silica.

Formation of silica by low-temperature acid alteration of Martian rocks: Physical-chemical constraints

[1] Theoretical geochemical modeling has been used to evaluate the formation conditions of amorphous silica during aqueous alteration of typical Martian igneous rocks at 0 C. The models show that some silica can form during low-temperature alteration of mafic to ultramafic rocks over a large range of pH and water/rock ratios. Silica-dominated deposits, like those found at the Columbia Hills in ...

Formation of Martian Silica-rich Deposits through Rock Alteration: a Theoretical Assessment

Introduction: The secondary mineralogy of martian surface materials is consistent with aqueous alteration of mafic and ultramafic rocks [e.g., 1-3]. Alteration of mafic silicates results in the release of SiO2 into aqueous solution, followed by the precipitation of silica [4] and/or silica-rich minerals. The presence of these phases is consistent with data obtained at the Mars Pathfinder [4] an...

Physicochemical properties of concentrated Martian surface waters

[1] Understanding the processes controlling chemical sedimentation is an important step in deciphering paleoclimatic conditions from the rock records preserved on both Earth and Mars. Clear evidence for subaqueous sedimentation at Meridiani Planum, widespread saline mineral deposits in the Valles Marineris region, and the possible role of saline waters in forming recent geomorphologic features ...