Mineral-chemical comparisons of MAC88105 with Yamato lunar meteorites

Conference · Fri Nov 01 04:00:00 EST 1991 · Geochimica et Cosmochimica Acta; (United States)

OSTI ID:5142786

Takeda, Hiroshi; Mori, Hiroshi; Saito, Jun ^[1]; Miyamoto, Masamichi ^[1]

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1. Univ. of Tokyo (Japan)

The new lunar meteorite MAC88105 has been studied by mineral-chemical techniques and was compared with the Yamato lunar meteorites. Clast types and pyroxene compositions of MAC88105 indicate that evidence for a pairing with any known lunar meteorites is unlikely. Clast-laden vitric breccia and comminuted mineral fragments in glassy matrix are common components as in other lunar meteorites, but granulitic clasts are not as common as in other lunar meteorites. The large and common granulite-like meta-igneous clasts still preserve lath-shaped plagioclase crystals with fine-grained olivine and pyroxenes in the interstices. Pyroxenes with mg number = Mg {times} 100/(Mg + Fe) between 70-48 mol% are common, but more Mg-rich pyroxenes and plutonic pyroxenes from nonmare pristine crustal rocks are rare. One basaltic clast contains pyroxenes with zoning trends more MG-rich than the above mg range and than those of the VLT basalts common in lunar meteorites. MAC88105 preserves true glass in the matrix as observed by a transmission electron microscope (TEM). The preservation of glassy materials indicates that MAC 88105 had a metamorphic annealing history different from other lunar meteorites.

• OSTI ID: 5142786
• Report Number(s): CONF-9003166--
• Conference Information: Journal Name: Geochimica et Cosmochimica Acta; (United States) Journal Volume: 55:11
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ANNEALING
BASALT
CHEMICAL COMPOSITION
GEOLOGIC HISTORY
GRANULITES
HEAT TREATMENTS
IGNEOUS ROCKS
LUNAR MATERIALS
MATERIALS
METAMORPHIC ROCKS
METAMORPHISM
METEORITES
MINERALOGY
MINERALS
OLIVINE
OXYGEN COMPOUNDS
PETROGENESIS
PYROXENES
RECRYSTALLIZATION
ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
VOLCANIC ROCKS