Northwest Africa 5958: a weakly altered CM-related ungrouped chondrite, not a CI3 [EPA]

http://arxiv.org/abs/1702.05955


Northwest Africa (NWA) 5958 is a carbonaceous chondrite found in Morocco in 2009. Preliminary chemical and isotopic data leading to its initial classification as C3.0 ungrouped have prompted us to conduct a multi-technique study of this meteorite and present a general description here. The petrography and chemistry of NWA 5958 is most similar to a CM chondrite, with a low degree of aqueous alteration, apparently under oxidizing conditions, and evidence of a second, limited alteration episode manifested by alteration fronts. The oxygen isotopic composition, with $\Delta^{17}$O = -4.3 $\permil$, is more 16O-rich than all CM chondrites, indicating, along with other compositional arguments, a separate parent body of origin. We suggest that NWA 5958 be reclassified as an ungrouped carbonaceous chondrite related to the CM group.

Read this paper on arXiv…

E. Jacquet, J. Barrat, P. Beck, et. al.
Tue, 21 Feb 17
70/70

Comments: 32 pages, 12 figures