Beryllium‐boron and aluminum‐magnesium chronology of calcium‐aluminum‐rich inclusions in CV chondrites

Abstract— We have made Be‐B measurements in six calcium‐aluminum‐rich inclusions (CAIs) (mostly type B inclusions) from CV chondrites and compared them to Al‐Mg measurements. All CAIs show ¹⁰B excesses in melilite that are correlated with Be/B ratios. The initial ¹⁰Be/⁹Be ratio inferred from the correlation line is 6.2 times 10^?4. In contrast to the Be‐B system in melilite, the Al‐Mg system in anorthite is disturbed. This is probably due to B diffusion in melilite being slow compared with Mg diffusion in anorthite. This suggests that Be‐B chronology may be useful for measuring time differences of high‐temperature (melting, condensation, etc.) events in the early solar system.