The Bholghati howardite: Petrography and mineral chemistry

Journal Article · Wed Aug 01 00:00:00 EDT 1990 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(90)90041-I· OSTI ID:5980433

Reid, A M; Buchanan, P ^[1]; Zolensky, M E ^[2]; Barrett, R A ^[3]

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1. Univ. of Houston, TX (USA)
2. NASA, Houston, TX (USA)
3. Lockheed Engineering and Sciences Co., Houston, TX (USA)

A 10 g sample of the Bholghati howardite was disaggregated in order to separate two eucrite clasts, several small carbonaceous clasts, fragments of diogenitic pyroxene, and bulk matrix. The eucrite clasts show evidence of moderately rapid cooling from a melt, followed by prolonged subsolidus annealing. The carbonaceous clasts mostly resemble CM2 carbonaceous chondrites with low-iron silicates and Fe-Ni sulfides in a fine grained dark matrix. One clast, however, is mineralogically, petrographically, and compositionally similar to a CI1 chondrite. Both carbonaceous and eucritic clasts have a complex history prior to incorporation into the howardite matrix with no evidence of significant metamorphism since assembly. Most clasts in the howardite breccia are monomineralic, with pyroxene and plagioclase predominant. Pyroxenes range from diogenitic to eucritic with diogenitic compositions most abundant; a significant number of intermediate compositions are present, consistent with derivation from a series of rocks related by fractionation.

• OSTI ID: 5980433
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 54:8; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
640106 -- Astrophysics & Cosmology-- Cosmology
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANNEALING
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHONDRITES
GEOLOGIC HISTORY
HEAT TREATMENTS
METEORITES
MINERALOGY
MINERALS
OXYGEN COMPOUNDS
PETROCHEMISTRY
PETROGRAPHY
PYROXENES
SILICATES
SILICON COMPOUNDS
STONE METEORITES