Rates of oxidative weathering on the surface of Mars
| Autor: | Duncan S. Fisher, Roger G. Burns |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Atmospheric Science
Inorganic chemistry Soil Science Mineralogy Weathering Aquatic Science engineering.material Oceanography Ferrous Hydrous ferric oxides Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Pyrrhotite Dissolution Earth-Surface Processes Water Science and Technology Aqueous solution Ecology Paleontology Forestry Mars Exploration Program Geophysics Space and Planetary Science engineering Pyrite Geology |
| Zdroj: | Journal of Geophysical Research: Planets. 98:3365-3372 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/92je02055 |
| Popis: | A model of acid weathering is proposed for the iron-rich basalts on Mars. Aqueous oxidation of iron sulfides released SO4(2-) and H(+) ions that initiated the dissolution of basaltic ferromagnesian silicates and released Fe(2+) ions. The Fe(2+) ions eventually underwent ferrolysis reactions and produced insoluble hydrous ferric oxide phases. Measurements of the time-dependence of acid weathering reactions show that pyrrhotite is rapidly converted to pyrite plus dissolved ferrous iron, the rate of pyrite formation decreasing with rising pH and lower temperatures. On Mars, oxidation rates of dissolved Fe(2+) ions in equatorial melt-waters in contact with the atmosphere are estimated to lie in the range 0.3-3.0 ppb Fe/yr over the pH range 2 to 6. Oxidation of Fe(2+) ions is estimated to be extremely slow in brine eutectic solutions that might be present on Mars and to be negligible in the frozen regolith. |
| Databáze: | OpenAIRE |
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