Northwest Africa 5958: A weakly altered CM-related ungrouped chondrite, not a CI3
Abstract
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 multitechnique 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 ∆'17O = -4.3‰, 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.
- Publication:
-
Meteoritics and Planetary Science
- Pub Date:
- May 2016
- DOI:
- 10.1111/maps.12628
- arXiv:
- arXiv:1702.05955
- Bibcode:
- 2016M&PS...51..851J
- Keywords:
-
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 32 pages, 12 figures