Calcium carbonate and sulfate of possible extraterrestrial origin in the EETA 79001 meteorite

Journal Article · Fri Apr 01 00:00:00 EST 1988 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(88)90361-4· OSTI ID:5181161

Gooding, J L; Wentworth, S J; Zolensky, M E ^[1]

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1. NASA/Johnson Space Center, Houston, TX (USA)

Two varieties of Ca-carbonate were found in a total of three interior (>2-cm depth) samples of glass inclusions from the shergottite meteorite, Elephant Moraine, Antarctica, A79001. Two of the samples, including the largest deposit around a vug near the center of the meteorite (8-cm depth), contained veins of granular calcite with significant magnesium and phosphorus, either as Mg-calcite with dissolved P or as calcite with very finely intergrown Mg-bearing phosphate. The second variety, which occurred in a third sample with a previously documented high concentration of trapped gases, consisted of disseminated 10-20 {mu}m, anhedral grains of nearly pure CaCO{sub 3} and was intimately associated with laths and needles of Ca-sulfate (possibly gypsum). The coexisting carbonate and sulfate appeared to be partially decrepitated, relict grains that were trapped during rapid solidification of quench-textured pyroxene and glass. For at least the latter occurrence, textural relationships clearly indicate a pre-terrestrial origin for the salts. All evidence considered, it is probably that both varieties of Ca-carbonate (and the Ca-sulfate) formed on a planetary body (probably Mars) before the meteorite fell on Earth.

• OSTI ID: 5181161
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Vol. 52:4; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
INCLUSIONS
CHEMICAL COMPOSITION
METEORITES
COSMOLOGICAL MODELS
ANTARCTICA
CALCITE
GEOCHEMISTRY
GEOLOGIC HISTORY
GLASS
MARS PLANET
MINERALOGY
ORIGIN
PLANETARY EVOLUTION
ALKALINE EARTH METAL COMPOUNDS
ANTARCTIC REGIONS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATES
CHEMISTRY
MATHEMATICAL MODELS
MINERALS
OXYGEN COMPOUNDS
PLANETS
POLAR REGIONS
SOLAR SYSTEM EVOLUTION
580000* - Geosciences