Sample No.: ALHA77254

Location: Allan Hills

Field No.: 77122704

Weight (gms): 245.8

Meteorite Type: L5 Chondrite

Physical Description:

Very thin, dull, black fusion crust is present on two surfaces (T&N) of the meteorite. The surfaces are free of fusion crust, have a dull, orangish-brown weathering patina, with the exception of the B surface, which is a shiny orangish-brown. From field photographs it was determined that this angular specimen had its B surface in contact with the ice at the time of recovery. The B surface has slickensides. The specimen is 10.5x5.0x4.0 cm. Many inclusions are visible on the sawed surface of the meteorite, which range to as much as 1 cm in length. Discoloration, due to weathering, of the outer most material was observed to a depth of approximately 1.5 cm along the S surface.

Petrographic Description: Brian Mason

The section shows well-developed chondritic structure, the chondrules ranging from 0.3-2.1 mm in diameter; a variety of types is present, the commonest being barred olivine, granular olivine and olivine-pyroxene, and radiating pyroxene. The chondrules are set in a granular matrix of olivine and orthopyroxene, with minor subequal amounts of nickel-iron and troilite. Limonitic staining and a few patches of red-brown limonite are associated with the metal grains. Fusion crust is present along one edge of the section. Microprobe analyses show olivine (Fa23) and orthopyroxene (Fs20) of essentially uniform composition. The meteorite is classified as an L5 chondrite.