Galactic Cosmic Rays and the Light Elements

The study of the light elements abundances in low metallicity stars offers a unique way to learn about the past content of our Galaxy in energetic particles (EPs). This study teaches us that either the light elements are not produced by cosmic rays interactions in the interstellar medium (ISM), as has been thought for 30 years, or the cosmic rays are not what one usually thinks they are, namely standard interstellar material accelerated by the shock waves generated by supernova explosions. In any case, we have to revise our understanding of the EPs in the Galaxy. Relying on the observational evidence about Li, Be and B Galactic evolution as well as about the distribution of massive stars, we show that most of the EPs responsible for the production of light elements must be accelerated inside superbubbles, as is probably the case for the standard Galactic cosmic rays as well.