Abstract
Acid weathering of plagioclase-pyroxene mixtures has been investigated with an open system kinetic dissolution model. The modeling reveals that elevated plagioclase/pyroxene ratios observed in some low-albedo martian regions and atmospheric dust could be partially caused by preferential dissolution of pyroxenes at pHs below ∼3-4. Surface materials with smaller grain sizes, affected by lower pH fluids, and/or exposed to longer durations of acid weathering would be enriched in plagioclase. If preferential dissolution is responsible for the observed mineral ratios, the dissolution process likely occurred on a large scale, such as weathering by acid atmospheric precipitates. If dissolution was continuous, modeled timeframes required to produce a high plagioclase/pyroxene ratio are short on geologic timescales; however, it is likely that acid weathering on Mars was episodic, possibly occurring over a longer period of time.
Original language | English (US) |
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Pages (from-to) | 90-96 |
Number of pages | 7 |
Journal | Icarus |
Volume | 196 |
Issue number | 1 |
DOIs | |
State | Published - Jul 1 2008 |
Keywords
- Mars
- Mineralogy
- surface
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science