| MetSoc Home Publications Contacts |
|
||
|
||
| Allan Hills A78006 | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Basic information | Name: Allan Hills A78006 This is an OFFICIAL meteorite name. Abbreviation: ALHA78006 This meteorite may also be called Allan Hills 78006 (ALH 78006) in publications. Observed fall: No Year found: 1978 Country: Antarctica [Collected jointly by ANSMET (US) and NIPR (Japan)] Mass:  8 g | ||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 453 approved meteorites classified as Howardite. [show all] Search for other: Achondrites, HED achondrites, and Howardites | ||||||||||||||||||||||||||||||||
| Writeup |
Writeup from AMN 2(2):
This text was reprinted from AMN 2(2) in AMN 4(1). In some cases, it may be an updated version from the original. Sample No. ALHA78006 Location: Allan Hills Field No.: 277 Weight (gms): 8.0 Meteorite Type: Howardite
Physical Description: This is a nearly complete specimen (3.0 x 1.5 x 2.0 cm). Shiny black fusion crust covers all of the stone with the exception of portions of the E, W and S surfaces. There the sample is void of fusion crust, light to dark gray interior material is exposed. A non-weathered brecciated surface with no metal exposed was revealed upon leaving this stone in half.
Petrographic Description: Brain Mason The thin section shows a complex breccia of angular fragments (grains up to 1 mm long) of pyroxene (orthopyroxene and pigeonite and plagioclase, with numerous polymineralic enclaves, set in a matrix of comminuted pyroxene and plagioclase. Accessory chromite and ilmenite and trace amounts of troilite and nickel-iron are present. The enclaves are holocrystalline pyroxene-plagioclase aggregates, and vary considerably in texture from coarse-grained gabbroic to fine-grained basaltic types. Slight weathering is indicated by small areas of rusty staining, usually in association with metal grains. Microprobe analyses show a wide range in pyroxene composition: Wo2-12En31-72Fs25-61; a number of grains with uniform composition Wo3En11Fs26 suggests the presence of a diogenitic component. Plagioclase averages An91. A single grain of iron-rich olivine (Fa81) was analyzed. The meteorite is classified as a polymict pyroxene-plagioclase achondrite (howardite). | ||||||||||||||||||||||||||||||||
| Data from: MB76 Table 2 Line 262: |
|
||||||||||||||||||||||||||||||||
| Catalogs: |
| ||||||||||||||||||||||||||||||||
| References: | Published in Antarctic Meteorite Newsletter 2(2) (1979), JSC, Houston Published in Meteoritical Bulletin, no. 76, Meteoritics 29, 100-143 (1994)
| ||||||||||||||||||||||||||||||||
Geography:
|
Statistics: This is 1 of 44248 approved meteorites from Antarctica (plus 3802 unapproved names) | ||||||||||||||||||||||||||||||||
| Proximity search: | |||||||||||||||||||||||||||||||||