Antarctic Search for Meteorites (ANSMET) Search this
Weight:
0.05 g
Place:
Antarctica
Collection Date:
1977
Notes:
# NASA data for ALH 77005 Weathering: A Fracturing: A Fa: 28 mol % Fs: 23 mol % ²⁶Al: 55 ± 2 dpm/kg
The specimen is well rounded on all faces except the south face, which is a partially broken surface. A well developed, dark fusion crust randomly covers approximately 5% of the meteorite's surface in small, thin patches. Parts of the stone are covered by a vitreous crust that possibly is the lower portion of the dark, outer fusion crust, which has been physically abraded. Some partially melted crystals are in contact with this glassy rind. The specimen's dimensions are ~9.5 cm x 7.5 cm x 5.25 cm.<br /><br />The specimen is well-indurated and difficult to chip. This would be a good meteorite for the study of fusion crust. The outer dark crust has apparently been removed by physical weathering. There is little evidence that the glassy rind has been affected by chemical weathering. The thin section chip may not be representative of the entire specimen.<br /><br />On the cut surface the sample appears to be fresh. Variations in color of sawed surface suggest heterogeneities on a centimeter scale. Voids up to 2 mm in diameter are present on the sawed surface. Some of these voids show crystal structures on the peripheral surface, but they do not appear to extend into the cavity.
