The section shows a brecciated structure, with clasts of orthopyroxene, pigeonite, and plagioclase up to 1.2 mm across in a comminuted groundmass of these minerals; two gabbroic clasts, 3.2 and 1.8 mm across, were noted. Microprobe analyses show a wide range in pyroxene compositions: Wo1-22, Fs20-53, En35-79; orthopyroxene compositions cluster around Wo3Fs24. Plagioclase composition is An90-95. The meteorite is a howardite; mineral compositions and texture are similar to the EET87503 group of howardites, and the possibility of pairing should be considered. |
An initially defined pairing group (e.g., AMN 11, 2) consisting of EET 87503, EET 87509, EET 87510, EET 87512, EET 87518, and EET 87531 has been re-evaluated by Mittlefehldt et al. (2013). Based on petrography, mineralogy, petrology, bulk composition, and find locations, EET 87503 was removed from this group (and instead paired with EET 87513), and EET 87512 was removed from this group to be unpaired. The original group also gained EET 92002, EET 83376 (previously unpaired), EET 87532 (previously unpaired), and two from 1999 field season EET 99400 and EET 99408. Thus, the newly revised pairing groups are EET 87503 (503 and 513) and EET 87509 (EET 87509, EET 87510, EET 87518, and EET 87531, EET 87532, EET 83376, EET 92022, EET 99400 and EET 99408). EET 87512 is unpaired. |