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Allan Hills A77264 | |||||||||||||||||||||
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Basic information | Name: Allan Hills A77264 This is an OFFICIAL meteorite name. Abbreviation: ALHA77264 This meteorite may also be called Allan Hills 77264 (ALH 77264) in publications. Observed fall: No Year found: 1977 or 1978 Country: Antarctica [Collected jointly by ANSMET (US) and NIPR (Japan)] Mass: 11 g | ||||||||||||||||||||
Classification history: |
This is 1 of 11505 approved meteorites (plus 23 unapproved names) classified as H5. [show all] Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||
Writeup |
Writeup from AMN 4(1):
Sample No.: ALHA77264 Location: Allan Hills Field No.: B78010301 Weight (gms): 10.97 Meteorite Type: H5 Chondrite
Physical Description: The stone is tabular with well-defined edges and is completely covered by a slightly glassy, brownish-black fusion crust. One surface shows cracks that have weathered rusty, and a cavity which is a nearly perfect hemisphere. Chipping for a thin section sample revealed a fresh surface containing rust stains and fresh metal particles. The approximate dimensions of sample: 2.75x2.0x1.5 cm.
Petrographic Description: Brian Mason Chondrules are prominent and well-defined, 0.3-1.2 in diameter; porphyritic olivine, barred olivine, and radiating pyroxene chondrules were noted. The matrix is medium-grained (grains up to 0.2 mm), and consists largely of olivine and pyroxene, with minor amounts of nickel-iron, troilite, and plagioclase; the plagioclase occurs as small grains in the matrix and in the bars of some chondrules. Fusion crust, up to 1 mm thick, is preserved on one edge. The sections show extensive limonitic staining, and limonite is concentrated around nickel-iron grains. Microprobe analyses give a mean composition of Fa19 for olivine and Fs16 for orthopyroxene. The meteorite is classified as an H5 chondrite. | ||||||||||||||||||||
Data from: MB76 Table 2 Line 215: |
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Catalogs: |
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References: | Published in Antarctic Meteorite Newsletter 4(1) (1981), JSC, Houston Published in Meteoritical Bulletin, no. 76, Meteoritics 29, 100-143 (1994)
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Geography: |
Statistics: This is 1 of 44400 approved meteorites from Antarctica (plus 3802 unapproved names) | ||||||||||||||||||||
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Revision history: |
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