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| Allan Hills A81187 | |||||||||||||||||||||||||||||
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| Basic information | Name: Allan Hills A81187 This is an OFFICIAL meteorite name. Abbreviation: ALHA81187 This meteorite may also be called Allan Hills 81187 (ALH 81187) in publications. Observed fall: No Year found: 1981 Country: Antarctica [Collected by US Antarctic Search for Meteorites program (ANSMET)] Mass:  40 g | ||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 91 approved meteorites classified as Acapulcoite. [show all] Search for other: Acapulcoite-lodranite family, Acapulcoites, and Primitive achondrites | ||||||||||||||||||||||||||||
| Writeup |
Writeup from AMN 7(2):
Sample No.: ALHA81187 Location: Allan Hills Field No.: 1236 Weight (gms): 40.0 Meteorite Type: Achondrite (unclassified)/Forsterite Chondrite
Physical Description: Roberta Score Fusion crust covers two surfaces, one of which contains remnants of flow features. Several cracks penetrate the mostly weathered interior of the stone. Dimensions: 4.5 x 2.5 x 2 cm
Petrographic Description: Brian Mason The section shows an aggregate of anhedral to subhedral grains, 0.05-0.6 mm across, of pyroxene and olivine, with about 20% of disseminated nickel-iron and minor amounts of plagioclase, troilite, and schreibersite. The proportion of pyroxene to olivine is estimated at 4:1. Weathering is extensive, with veinlets and small areas of brown limonite throughout the section. Microprobe analyses give the following compositions: olivine, Fa4; pyroxene, Wo3Fs6.5; plagioclase, An18. The meteorite is tentatively considered to be an achondrite (unclassified), but it may belong to the small group of forsterite chondrites (Graham et al., Mineralogical Magazine, v. 41, p. 201, 1977). | ||||||||||||||||||||||||||||
| Data from: MB76 Table 2 Line 710: |
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| References: | Published in Antarctic Meteorite Newsletter 7(2) (1984), 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 44048 approved meteorites from Antarctica (plus 3802 unapproved names) | ||||||||||||||||||||||||||||
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