Accretional and alterational differences in a carbonaceous chondrite parent body: Evidence from the NWA 5491 CV 3 meteorite

• Published in: Meteoritics & planetary science Vol. 52; no. 3; pp. 428 - 442
• Main Authors: Kereszturi, A., Gyollai, I., Jozsa, S., Kanuchova, Z.
• Format: Journal Article
• Language: English
• Published: 01-03-2017
• ISSN: 1086-9379; 1945-5100
• DOI: 10.1111/maps.12802

Abstract
The
NWA
5491
CV
3 meteorite is a
CV
oxA subtype, and composed of two substantially different units (titled “upper” and “lower” units) in the cm size range with original accreted material and also subsequent alteration produced features. Based on the large chondrules in the “upper” unit and the small chondrules plus
CAI
s in the “lower” unit, they possibly accreted material from different parts of the solar nebula and/or at different times, whereas substantial changes happened in the nebula's composition. Differences are observed in the level of early fragmentation too, which was stronger in the upper units. During later alteration oxidizing fluids possibly circulated only in the upper unit, mechanical fragmentation and resorption were also stronger there. In the last phase of the geological history these two rock units came into physical contact, but impact‐driven shock effects were not observed. The characteristics of this meteorite provide evidence that the same parent body might accrete substantially different material and also the later processes could differ spatially in the parent body.