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| Allan Hills A78262 | |||||||||||||||||||||
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| Basic information | Name: Allan Hills A78262 This is an OFFICIAL meteorite name. Abbreviation: ALHA78262 This meteorite may also be called Allan Hills 78262 (ALH 78262) in publications. Observed fall: No Year found: 1978 Country: Antarctica [Collected jointly by ANSMET (US) and NIPR (Japan)] Mass:  26.2 g | ||||||||||||||||||||
| Classification history: |
This is 1 of 581 approved meteorites classified as Ureilite. [show all] Search for other: Achondrites, Ureilites | ||||||||||||||||||||
| Writeup |
Writeup from AMN 3(2):
This text was reprinted from AMN 3(2) in AMN 4(1). In some cases, it may be an updated version from the original. Sample No.: ALHA78262 Location: Allan Hills Field No.: 500 Weight (gms): 26.18 Meteorite Type: Ureilite
Physical Description: The overall shape of this specimen (4.0 x 2.5 x 2.0 cm) is triangular. A thin, dull black fusion crust is present on three surfaces. The remaining surfaces are fracture surfaces that are rough on a small scale. The surface roughness appears to be the result of exposed crystal faces. The overall color is very dark greenish-black. Chipping of the specimen during processing revealed a brownish coarse grained material. Many crystal faces were exposed on the interior surfaces
Petrographic Description: Brian Mason The section consists almost entirely of olivine, in rounded to subhedral grains 0.3-2.2 mm across; most of the olivine is colorless, but some grains have a pale brownish tint. A little pyroxene of similar grain size is present. The grains are rimmed with black carbonaceous material, which contains trace amounts of nickel-iron and troilite. Very thin fusion crust rims part of the section. Microprobe analyses show olivine and pyroxene of uniform composition. Olivine has a composition of Fa22; and a notably high content of calcium (CaO 0.4 weight percent) and chromium (Cr2O3 0.8 weight percent). Pyroxene composition is Wo8Fs19En73, with Cr2O3 1.2 weight percent. This meteorite is a ureilite and resembles ALHA78019 in all respects. | ||||||||||||||||||||
| Data from: MB76 Table 2 Line 438: |
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| References: | Published in Antarctic Meteorite Newsletter 3(2) (1980), 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 40849 approved meteorites from Antarctica (plus 4494 unapproved names) | ||||||||||||||||||||
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