NORTHWEST AFRICA 12416


C3-ungrouped
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Purchased July 2018
no coordinates recorded

Numerous friable, fusion-crusted stones having a combined weight of 875 g were purchased from a Moroccan source by several meteorite dealers. Samples were sent for analysis and classification to the University of Washington in Seattle (A. Irving and S. Kuehner) and Arizona State University (L. Garvie), and it was determined that NWA 12416 is an ungrouped carbonaceous chondrite of petrologic type 3.

The meteorite has a relatively high abundance (~50%) of fine-grained matrix containing small chondrules, mineral fragments, and AOAs. In addition, minor kamacite and pentlandite are present, but no CAIs or phyllosilicates were observed. The oxygen isotope composition of NWA 12416 was obtained by laser fluorination at the University of New Mexico (K. Ziegler), and the meteorite has unique oxygen isotope values distinct from those of the CV, CK, and CM groups, but similar to those for the C-ungrouped NWA 8781, the C3-ungrouped Telakoast 001, and the C2-ungrouped NWA 13167 and NWA 13479 (see diagrams below).

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Diagram from MetBull 108

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Diagram from MetBull 107

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Diagram from MetBull 110

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Diagram from MetBull 109

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Diagram from MetBull 109

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Diagram credit: Greenwood et al., GCA, vol. 277, p. 381 (2020, open access link)
'Linking asteroids and meteorites to the primordial planetesimal population'
(https://doi.org/10.1016/j.gca.2020.02.004)

Further isotopic analyses including 54Cr will help resolve the potential genetic relationships for these ungrouped meteorites. The specimen of NWA 12416 shown above and below is a small 0.85 g fragment acquired from Mark Lyon.

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