Abstract
Carbonaceous chondrites are meteorites that represent ancient Solar System material, and are classified into groups separating different parent bodies. CML 1689 and CML 1723 are two carbonaceous chondrites that appeared atypical to official groups and required further investigation in order to classify. CML 1723 contains an abundance of magnetite grains, porphyritic chondrules, and a lack of CAIs and metals. The fayalite contents of olivine grains and the composition of the magnetite grains are consistent with a CK chondrite. The moderate discernability of chondrules and equilibrated olivine compositions are typical of a type 5 chondrite, representing a moderately metamorphosed meteorite. CML 1723 has subsequently been submitted to the Meteoritical Society as a CK5 chondrite, and is awaiting official approval. CML 1689 contains abundant inclusions such as large chondrules and CAIs, but no metals. The abundance of inclusions, iron-rich minerals, and lack of metals suggests an oxidized CV chondrite, but CML 1689 contains less fayalitic matrix olivines than typical CVs, preventing a simple classification. It has affinities to CKs, CVs, and the proposed CV4 chondrite from MacPherson et al. (2023). CML 1689 has been submitted as a C3 ungrouped and will be the subject of further analysis for a definitive classification.
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Recommended Citation
Morrelli, Nico and Hutson, Melinda (2025) "An Examination of Two Atypical Carbonaceous Chondrites," PSU McNair Scholars Online Journal: Vol. 18: Iss. 1, Article 5.