  We report Li and B isotopic compositions of 10 Spinel-HIBonite spherules
(SHIBs) separated from the Murchison meteorite, in order to understand their
irradiation history in the early Solar System. The extremely low Be
concentrations in SHIBs preclude detection of extinct 10Be, but instead allow
for a search of the original Li and B isotopic ratios of the grains, as these
isotopes are sensitive indicators for irradiation. We found that some of the
SHIBs carried sub-chondritic 7Li/6Li and supra-chondritic 10B/11B ratios.
Considering two possible irradiation scenarios that could have occurred in the
early Solar System, irradiation of hibonite solids followed by addition of
isotopically normal Li and B seems to be the most plausible explanation for the
observed Li and B isotope ratios.
