|
Allan Hills A77261 | |||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Basic information | Name: Allan Hills A77261 This is an OFFICIAL meteorite name. Abbreviation: ALHA77261 This meteorite may also be called Allan Hills 77261 (ALH 77261) in publications. Observed fall: No Year found: 1977 Country: Antarctica [Collected jointly by ANSMET (US) and NIPR (Japan)] Mass: 412 g | ||||||||||||||||||||
Classification history: |
This is 1 of 12727 approved meteorites (plus 11 unapproved names) classified as L6. [show all] Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||
Writeup |
Writeup from AMN 2(1):
This text was reprinted from AMN 2(1) in AMN 4(1). In some cases, it may be an updated version from the original. Sample No.: ALHA77261 Location: Allan Hills Field No.: 77123021 Weight (gms): 411.7 Meteorite Type: L6 Chondrite
Physical Description: The stone is angular and ~8.5x5.0x5.5 cm. Fusion crust covers ~75% of the sample, is dull black and approximately 0.5 mm thick. In places the fusion crust has weathered to a reddish color. Polygonal fractures are present on all surfaces with fusion crust. The surfaces devoid of fusion crust are polished. One large fracture penetrates the entire stone. A few weathered, reddish-brown, chondrules (?), up to as much as 0.5 cm, are apparent on the stone. Cleaving reveals fresh matrix material that is grayish-white and contains small metallic flakes. The exterior weathering penetrates the specimen up to a depth of 2.5 cm. One irregular (0.5 cm in maximum length), gray, lithic clast(?) is apparent on the cleaved surface.
Petrographic Description: Brian Mason The section shows sparse and poorly-defined chondrules, merging with the granular groundmass, which consists largely of olivine and orthopyroxene with minor sub-equal amounts of nickel-iron and troilite; small grains of plagioclase are scattered throughout the groundmass. About one-third of the section is bordered by well-developed fusion crust, up to 0.6 mm thick. A little limonite and limonitic staining is present, concentrated around the nickel-iron grains. Microprobe analyses show olivine (Fa24), orthopyroxene (Fs21), and plagioclase (An11) of uniform composition; accessory merrillite was identified with the microprobe. The meteorite is classified as an L6 chondrite. | ||||||||||||||||||||
Data from: MB76 Table 2 Line 212: |
|
||||||||||||||||||||
Catalogs: |
| ||||||||||||||||||||
References: | Published in Antarctic Meteorite Newsletter 2(1) (1979), JSC, Houston Published in Meteoritical Bulletin, no. 76, Meteoritics 29, 100-143 (1994)
| ||||||||||||||||||||
Geography: |
Statistics: This is 1 of 44400 approved meteorites from Antarctica (plus 3802 unapproved names) | ||||||||||||||||||||
Proximity search: | |||||||||||||||||||||
Also see: |
This lists the most popular meteorites among people who looked up this meteorite.
| ||||||||||||||||||||
Revision history: |
This lists important revisions made to data for this record.
|