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| Allan Hills 84004 | |||||||||||||||||||||
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| Basic information | Name: Allan Hills 84004 This is an OFFICIAL meteorite name. Abbreviation: ALH 84004 Observed fall: No Year found: 1984 Country: Antarctica [Collected by US Antarctic Search for Meteorites program (ANSMET)] Mass:  9 kg | ||||||||||||||||||||
| Classification history: |
This is 1 of 6434 approved meteorites (plus 2 unapproved names) classified as H4. [show all] Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||
| Writeup |
Writeup from AMN 8(2):
Sample No.: ALH84004 Location: Allan Hills Weight (g): 9000.0 Field No.: 2505 Dimensions (cm): 21 x 16 x 16 Meteorite Type: H4 Chondrite
Macroscopic Description: Carol Schwarz Slightly weathered fusion crust covers this large specimen. Deep regmaglypts are abundant as are deep crevasses that are filled in with fusion crust. Some salt deposit has formed. The interior is red-brown to dark grayish with some areas of light gray matrix visible.
Thin Section (,4) Description: Glenn MacPherson This chondrite is heavily stained by iron oxide, indicating that it has experienced a moderate degree of terrestrial weathering. Well-defined chondrules and clasts, up to 3.5 mm in diameter, are very closely packed. No isotropic glass is preserved anywhere, but devitrified glass is common. Olivine is uniformly Fa17-18 in composition. The pyroxene is commonly monoclinic, and is Fs16-19. Coarse kamacite, troilite, and taenite are abundant, with the metal phases considerably in excess of the sulfide. Chromite is accessory. In one portion of the thin section there is abundant black interstitial material that consists of veins, stringers, patches, and tiny globules of metal and sulfide in a microcrystalline intergrowth. These are probably shock veins. The silicates in this region show some evidence of brecciation and, locally, granulation. This is an H4 chondrite. | ||||||||||||||||||||
| Data from: MB76 Table 2 Line 970: |
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| References: | Published in Antarctic Meteorite Newsletter 8(2) (1985), 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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