Northwest Africa 5958: A weakly altered CM-related ungrouped chondrite, not a CI3

作者:Jacquet Emmanuel*; Barrat Jean Alix; Beck Pierre; Caste Florent; Gattacceca Jerome; Sonzogni Corinne; Gounelle Matthieu
来源:Meteoritics & Planetary Science, 2016, 51(5): 851-869.
DOI:10.1111/maps.12628

摘要

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 Delta ' O-17 = -4.3 parts per thousand, is more O-16-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.

  • 出版日期2016-5