A unique type 3 ordinary chondrite containing graphite-magnetite aggregates - Allan Hills A77011

• Main Authors: Mckinley, S. G., Scott, E. R. D., Taylor, G. J., Keil, K.
• Format: Other/Unknown Material
• Language: unknown
• Published: 1982
• Subjects: 91; Allan Hills; Antarc*; Antarctica
• Online Access: http://ntrs.nasa.gov/search.jsp?R=19820048209

ALHA 77011, which is the object of study in the present investigation, is a chondrite of the 1977 meteorite collection from Allan Hills, Antarctica. It contains an opaque and recrystallized silicate matrix (Huss matrix) and numerous aggregates consisting of micron- and submicron-sized graphite and magnetite. It is pointed out that no abundant graphite-magnetite aggregates could be observed in other type 3 ordinary chondrites, except for Sharps. Attention is given to the results of a modal analysis, relations between ALHA 77011 and other type 3 ordinary chondrites, and the association of graphite-magnetite and metallic Fe, Ni. The discovery of graphite-magnetite aggregates in type 3 ordinary chondrites is found to suggest that this material may have been an important component in the formation of ordinary chondrites.