Sample No.: ALHA77215

Location: Allan Hills

Field No.: 77122946

Weight (gms): 819.6

Meteorite Type: L3 Chondrite

Physical Description:

The surface of this specimen is mostly weathered surface, however a small remnant of the fusion crust remains. The E, W, and N surfaces are fracture surfaces that contain numerous chondrules and lithic clasts. The largest chondrule is approximately 0.5 cm in diameter. Both the chondrules and lithic clasts are commonly lighter color than the surrounding gray matrix. The fractures that are not covered with weathering rind range from greenish-brown to reddish brown. There are numerous fractures over the meteorite's surface. The sample is approximately 13.0 x 7.0 x 7.0 cm. The sample closely resembles ALHA77216, ALHA77217 and ALHA77252.

Petrographic Description: Brian Mason

The thin section shows well-developed chondritic structure, with a variety of chondrule types; chondrules range from 0.3 - 1.8 mm in diameter. The chondrules are set in a granular groundmass consisting largely of olivine and pyroxene (some grains polysynthetically twinned), with minor nickel-iron and troilite in approximately equal amounts. A minor amount of limonitic staining is present. Microprobe analyses show some variability in olivine and pyroxene compositions: olivine, Fa22-Fa26, average Fa23; pyroxene, Fs9-Fs21, average Fs15. The meteorite is classified as an L3 chondrite.