Mineralogical Criteria for the Parent Asteroid of the “Carbonaceous” Achondrite NWA 6704
AuthorMcGraw, Allison M.
Izawa, Matthew R. M.
Sanchez, Juan A.
Le Corre, Lucille
Cloutis, Edward A.
Applin, Daniel M.
AffiliationUniv Arizona, Lunar & Planetary Lab
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationAllison M. McGraw et al 2020 AJ 159 107
RightsCopyright © 2020. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractThe unique achondrite meteorite Northwest Africa (NWA) 6704 and its paired samples are fragments of an unknown parent asteroid that experienced large-scale igneous melting early in our solar system's history. The geochemistry and mineralogy of NWA 6704 show that its parent asteroid has affinities with carbonaceous chondrites and that the precursor materials were relatively oxidized. While large-scale melting has affected the meteorite, there is no evidence for equilibration with a metallic melt. NWA 6704 paired meteorites therefore provide insights into the evolution of planetesimals and bodies that accreted from source materials, possibly in the ice-rich outer solar system. Currently, we lack an understanding of the distribution of potential parent asteroids of the NWA 6704 meteorites. We have undertaken a detailed multiwavelength (0.35-25 mu m) spectroscopic and geochemical investigation of NWA 6704 to provide constraints on the potential parent asteroids of these enigmatic meteorites. In comparison with asteroid spectra, NWA 6704 is similar to the S(VI) subtypes of the S-asteroid complex. By using the Bus-DeMeo Taxonomic Classifier, we determine that NWA 6704 has affinities toward V-type (Vesta type) asteroids. We have determined that the parent asteroid of NWA 6704 would be a V-type asteroid that is not dynamically linked to Vesta and also fall in the S(VI) subtype of the Band I center versus Band area ratio diagram. A search in the literature for potential parent bodies yielded one asteroid, (34698) 2001 OD22, as a possible candidate.
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