Evolution of sulfide mineralization on Mars

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

OSTI ID:5444956

Burns, R G; Fisher, D S ^[1]

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1. Massachusetts Institute of Technology, Cambridge (USA)

The presence of komatiitic igneous rocks on Marks, based on geochemical evidence from SNC meteorites and Viking X ray fluorescence analyses of the regolith, suggests that massive and disseminated iron sulfide mineralization occurs near the Martian surface. Analogies are drawn between possible ultramafic Fe-Ni sulfides on Mars and terrestrial pyrrhotite-pentlandite ore deposits associated with Archean komatiites formed during early crustal development on Earth. Partial melting of the mantle as a result of high radiogenic heat production then, extrusion of turbulent high-temperature ultramafic lavas, segregation of immiscible FeS melts during cooling, gravitational settling and fractional crystallization of sulfide minerals in magma chambers or lava flows produced massive and disseminated sulfide mineralization associated with terrestrial komatiites. Comparable processes probably occurred on Mars where, on account of the inferred higher Fe/(Fe + Mg) ratio of the X ray mantle (estimated to contain {approximately}4.5 wt % S), iron-rich basaltic magmas were produced by partial melting at depths and temperatures exceeding 165 km and 1,400{degree}C, respectively. Adiabatic diapiric emplacement of these iron-rich, very low viscosity basaltic melts transported significant concentrations of dissolved sulfur as S{sup 2{minus}} and HS{sup {minus}} from the mantle. Ensuing sulfide mineralization may have been either thinly disseminated within ultramafic lavas erupting over large areas of Mars or concentrated locally at the base of structural depressions. Cumulate ore deposits several meters thick may occur at the base of intrusions or in near-surface magma chambers. The evidence for insignificant plate tectonic activity on Mars and minimal interactions of Martian mantle with crust, hydrosphere and atmosphere has restricted the evolution of sulfide ore deposits there.

• OSTI ID: 5444956
• Report Number(s): CONF-9001119-; CODEN: JGREA
• 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
MARS PLANET
PLANETARY EVOLUTION
SULFIDES
MINERALIZATION
CHEMICAL COMPOSITION
GEOCHEMISTRY
IGNEOUS ROCKS
IRON SULFIDES
LEAD SULFIDES
MAGMA
MELTING
METEORITES
OVERBURDEN
PLATE TECTONICS
ZINC SULFIDES
CHALCOGENIDES
CHEMISTRY
INORGANIC PHOSPHORS
IRON COMPOUNDS
LEAD COMPOUNDS
PHASE TRANSFORMATIONS
PHOSPHORS
PLANETS
ROCKS
SOLAR SYSTEM EVOLUTION
SULFUR COMPOUNDS
TECTONICS
TRANSITION ELEMENT COMPOUNDS
ZINC COMPOUNDS
640107* - Astrophysics & Cosmology- Planetary Phenomena