Iron-sulfur mineralogy of Mars: Magmatic evolution and chemical weathering products

Conference · Thu Aug 30 00:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

OSTI ID:5445407

Burns, R G; Fisher, D S ^[1]

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1. Massachusetts Institute of Technology, Cambridge (USA)

Models for the evolution of sulfide minerals on Mars and reaction pathways to their oxidative weathering products in Martian regolith have been proposed based on petrogenetic associations between komatiitic rock types, Viking geochemical data, SNC meteorites, and terrestrial Fe-Ni sulfide deposits. To test the weathering model, komatiitic pyrrhotites and olivines were exposed to sulfuric acid solutions, with and without dissolved ferric iron added to simulate deep-weathering processes, and the reaction products were identified by Mossbauer spectroscopy. Secondary FeS{sub 2} (pyrite or marcasite), FeOOH (goethite), and possibly jarosite were formed from pyrrhotite, while olivine was oxidized to nanophase goethite. These results suggest that on Mars, acidic groundwater induced pyrrhotite {yields} FeS{sub 2} {yields} FeOOH (+jarosite) oxidative weathering reactions, particularly in the presence of dissolved Fe{sup 3+}. Such gossaniferous materials occurring in Martian regolith were derived mainly from Fe-Ni sulfides associated with komatiitic basalts and not from sulfides occurring in calc-alkaline porphyry copper deposits, granitic hydrothermal veins, sediment-hosted PbS-ZnS ores, etc., which presumably did not evolve on Mars due to the virtual lack of plate tectonic activity there.

• OSTI ID: 5445407
• Report Number(s): CONF-9001119-; CODEN: JGREA; TRN: 91-023772
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:B9; Conference: 4. international conference on Mars, Tucson, AZ (United States), 10-13 Jan 1990; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
IRON SULFIDES
MINERALOGY
MARS PLANET
GEOLOGY
BASALT
CHEMICAL COMPOSITION
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
MAGMA
MATHEMATICAL MODELS
OLIVINE
OVERBURDEN
PLANETARY EVOLUTION
ROCKS
SPECTROSCOPY
WATER
WEATHERING
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
HYDROGEN COMPOUNDS
IGNEOUS ROCKS
IRON COMPOUNDS
IRON SILICATES
MAGNESIUM COMPOUNDS
MAGNESIUM SILICATES
MINERALS
OXYGEN COMPOUNDS
PLANETS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SOLAR SYSTEM EVOLUTION
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VOLCANIC ROCKS
YIELDS
640107* - Astrophysics & Cosmology- Planetary Phenomena