HETEROGENEITY OF Mg ISOTOPES AND VARIABLE 26Al/27Al RATIO IN FUN CAIs
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Magnesium and 54Cr isotope compositions of carbonaceous chondrite chondrules – Insights into early disk processes
We report on the petrology, magnesium isotopes and mass-independent 54Cr/52Cr compositions (μ54Cr) of 42 chondrules from CV (Vigarano and NWA 3118) and CR (NWA 6043, NWA 801 and LAP 02342) chondrites. All sampled chondrules are classified as type IA or type IAB, have low 27Al/24Mg ratios (0.04-0.27) and display little or no evidence for secondary alteration processes. The CV and CR chondrules s...
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Introduction: Among the calcium-aluminum-rich inclusions (CAIs) there exists a small subgroup referred to as FUN CAIs (for Fractionation and Unidentified Nuclear effects [1]) that exhibit unusually large mass-dependent fractionations and mass-independent isotopic variations [1-3]. Understanding the origin, conditions of formation, genetic relationship of these inclusions with other CAIs and the...
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