Evidence of honeycomb weathering on Mars

Abstract

Abstract. Features similar to honeycomb weathering are observed in some Martian rocks at the Pathfinder landing site. Honeycomb weathering on Earth develops in a range of environments, including extremely arid and cold areas in Antarctica, and on many types of rocks, e.g. basalts and andesites, subjected to physical and/or chemical weathering. Salt weathering, in combination with frost shattering and chemical weathering, provides a viable explanation for the development of honeycomb features on Mars under current environmental conditions. Data supporting this theory are presented and discussed. These findings are important in understanding the present climate, geology, and, in particular, the geomorphology of Mars. They also suggest new paths for research and experimentation in future missions to Mars. (Fig. 1A-C) seem strikingly similar to the honeycomb features (masses of superficial centimetric to decimetric cavities limited by thin walls and resulting in granular disintegration of the host rock, which normally appears surrounded by debris [Mustoe, 1982]) developed on many terrestrial rocks decayed by intense physical and/or chemical weathering. Fig. 1D-F show details of honeycomb weathering developed on Earth rocks (basalts and sandstones) affected by cyclic salt crystallization processes (so-called "salt weathering" [Evans, 1970]). Questions that arise when looking at these images are: Does honeycomb weathering occur on Mars or do these features have another origin? If honeycomb weathering does occur, how does it take place? Here, possible answers to these questions are presented and discussed.

Decomposition reactions of magnesium sulfate hydrates and phase equilibria in the MgSO4–H2O and Na+–Mg2+–Cl−–SO42−–H2O systems with implications for Mars

“…Under such conditions, both natural rocks and building materials are subject to rapid decay (Ruiz-Agudo et al, 2007;Lopez-Arce et al, 2008;Steiger et al, 2008a). Similarities in the geomorphology of Mars to that of Earth led several authors to the conclusion that salt crystallization is also an important weathering mechanism of rock decay on Mars (Malin, 1974;Rodriguez-Navarro, 1998;Thomas et al, 2005;Jagoutz, 2006;Grindrod and Balme, 2010).…”

Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress

“…in deserts (Cooke and Smalley, 1968), in polar regions such as the dry Antarctic valleys (Wellman and Wilson, 1965;Evans, 1970) and at coastlines (Trenhaile, 1987). Similarities in the geomorphology of Mars to that of Earth led several authors to the conclusion that salt crystallization is also an important weathering mechanism of rock decay on Mars (Malin, 1974;Rodriguez-Navarro, 1998). Finally, it is accepted that salt weathering is a major cause of damage in building stones and other porous building materials such as brick and concrete (Goudie and Viles, 1997).…”

The chemical variability at the surface of Mars: Implication for sediment formation and rock weathering

“…In addition, physical weathering processes such as abrasion and mixing associated with aeolian activity (e.g., Bridges et al, 1999;Greley et al, 1982Greley et al, , 1999Greley et al, , 2002, freeze thaw and salt weathering (e.g., Rodriguez-Navarro, 1998) and the accumulation of meteoritic matter (Gibson, 1970;Clark and Baird, 1979;Boslough, 1998;Flynn and McKay, 1990;Flynn, 1996;Yen, 2001) were given attention.…”