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| Allan Hills A77118 | |||||||||||||||||||||||||
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| Basic information | Name: Allan Hills A77118 This is an OFFICIAL meteorite name. Abbreviation: ALHA77118 This meteorite may also be called Allan Hills 77118 (ALH 77118) in publications. Observed fall: No Year found: 1977 Country: Antarctica [Collected jointly by ANSMET (US) and NIPR (Japan)] Mass:  7.8 g | ||||||||||||||||||||||||
| Classification history: |
This is 1 of 10254 approved meteorites (plus 18 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.: ALHA77118 Location: Allan Hills Field No.: 77123118 Weight (gms): 7.84 Meteorite Type: H5 Chondrite
Physical Description: Specimen is rounded. A brownish-black fusion crust covers approximately 75% of the meteorite's surface. Approximately 25% of the specimen is a fracture surface. This is a nearly complete specimen. No fresh metal was observed on chipping. The maximum dimension is ~2.5 cm. From field photographs it is evident that the B surface was in contact with the ice.
Petrographic Description: Brian Mason Chondritic structure well-developed, with a variety of chondrule types, the commonest being barred olivine, granular and porphyritic olivine, and fine-grained pyroxene. The matrix is fine- to medium-grained, consisting of olivine, pyroxene, nickel-iron, and troilite. Fusion crust is present on one side of the section. The section is pervaded by yellow-brown limonitic material. Microprobe analyses show olivine (Fa19) and orthopyroxene (Fs17) of uniform composition; some small grains of sodic plagioclase were detected. | ||||||||||||||||||||||||
| Data from: MB76 Table 2 Line 93: |
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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:
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Statistics: This is 1 of 40744 approved meteorites from Antarctica (plus 4494 unapproved names) | ||||||||||||||||||||||||
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