CO3.1
(CO3.0 in MetBull 90)
Found 2005
no coordinates recorded
A single stone weighing 237 g was found in the Sahara Desert in Northwest Africa. The meteorite was subsequently purchased by A. Hupé and was submitted for analysis to Northern Arizona University (T. Bunch and J. Wittke). Northwest Africa 2918 was classified as a CO3.0 carbonaceous chondrite, among a paucity of highly unequilibrated CO chondrites including Colony, ALHA77307 and Y-81020. However, examining the content of Cr in ferroan olivine, Grossman et al. (2006) argue that NWA 2918 is more consistent with a CO3.1, similar to DOM 03238. Interestingly, they discovered a very rare compound chondrule–CAI within this CO chondrite, with the CAI exhibiting a Ti-rich core consiting of deep-blue colored spinel. This meteorite has been shocked to stage S1 and weathered to grade W2.
The petrology, chemistry, and mineralogy of NWA 2918 is very similar to the CO3.05 Colony, and this page can be accessed for further details. In addition, the Colony page contains information relating to the current refinements in the classification techniques which have enabled NWA 2918 to be distinguished as a highly unequilibrated CO3.1 chondrite. The photo of NWA 2918 shown above is a small 0.92 g partial slice.
