Meteoritical Bulletin, No. 107
Northwest Africa 12279
2016 October 10
History: The meteorite was purchased in Denver USA by Zhouping Guo and Guobing
Zhong on September, 2017 from Adam Aaronson.
Physical characteristics: A single
bulk specimen, with sepia fresh fusion crust and low weathering degree. A
large impact molten mass was observed in the specimen.
Petrography: This lunar
meteorite comprises two petrographic areas: impact melt breccia and
anorthosite. The anorthosite includes forsterite, pigeonite, low-Ca
pyroxene, plagioclase and minor minerals such as ilmenite, chromite, quartz
and other opaque minerals. It has a subophitic
structure. The impact-melt breccia contains various types of lithic clasts
(anorthosite, olivine-gabbro, gabbro), mineral and glassy fragments. The
matrix consists of very fine-grained, cryptocrystalline (~0.1mm) and vitric
particles with sporadic small vesicles.
Geochemistry: (J.K. Zhou, H.Y.
Chen, Z.P. Xia, Guilin University of Technology, China): Olivine, Fa12.8-46.3Fo53.8-87.3,
FeO/MnO=66.3-96.9 (n=29); Orthopyroxene, Fs15.5-32.2Wo2.98-4.22En64.9-80.3,
Fe/Mn(mol)=54.5-69.3 (n=3); Pigeonite: Fs23.2-53.1Wo7.19-23.7En39.8-57.4,
Fe/Mn(mol)=51.1-61.7 (n=6); Augite, Fs8.42-44.4Wo31.4-44.1En18.7-47.5,
Fe/Mn(mol)=37.1-53.9 (n=14); Plagioclase: An92.9-98.5Or0.06-0.69
(n=15); Spinel: MgO, 20.1%-23.6%; Al2O3, 59.5%-69.2%;
Cr2O3, 3.91%-6.00%; FeO,6.05%-7.46%.
(anorthositic impact-melt breccia)
Specimens: 30.2 g including
one polished thin section are deposited in College of Earth Sciences, Guilin
University of Technology, China; Remaining material with Guobing Zhong and Zhouping