Petrofabrics in fine-grained rims of Vigarano CV3 chondrite : insights from EBSD and AFM studies
Résumé
Fine grained rims (FGR) are commonly encountered around chondrules and CAI’s in CV carbonaceouschondrites. They are mostly composed by very fine grained (mi- cron to submicron) iron rich olivine.Whether the iron rich olivines are of nebular or parent body origin stays a matter of debate ([1],[2], [3]).While chemical and petrographic characterizations are abundant in the literature, only few studies concerningmicrotextures and fabrics of these fine grained olivines are available [4], [5], [6]. Recent EBSD study in Allende has stirred up the debate, since a spherical fabricaround chondrules has been discovered, supporting a nebular origin [5]. In order to further investigate the relationship between chondrules and fine grained rims,we present here EBSD and AFM analyses in Vigarano CV3 chondrite.