In situ oxygen, magnesium, and silicon isotopic compositions of the <scp>FUN</scp> inclusion Vigarano 1623‐5

Oxygen, magnesium, and silicon isotopic abundances in Vigarano 1623-5 were studied using secondary ion mass spectrometry to investigate correlations between petrologic properties of this unique forsterite-bearing FUN inclusion. displays large, correlated mass-dependent fractionation effects, tightly linked mineralogy within distinct units the The pyroxene-rich melilite-rich interior parts inclusion display highly mass-fractionated compositions oxygen, silicon, consistent with Rayleigh distillation during evaporation a melt initial oxygen composition close solar composition. However, chemical composition, enriched magnesium suggests precursor already fractionated by prior evaporation. A discontinuous igneous rim was produced flash-melting event followed exchange melilite planetary-like mechanical fragmentation, reassembly an accretionary heterogeneous materials. Al-rich minerals show evidence for having crystallized live 26Al but at less than “canonical” level most CV calcium-aluminum-rich inclusions. well-defined 26Al-26Mg isochrons are not found temporal implications ambiguous.