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

Conference · Thu Aug 30 04:00:00 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--
• Conference Information: Journal Name: Journal of Geophysical Research; (United States) Journal Volume: 95:B9
• Country of Publication: United States
• Language: English

Related Subjects

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