The role of gravitational supernovae on the galactic evolution of the   LiBeB isotopes
  The observed Be and B relationships with metallicity clearly support the idea that both elements have a primary origin and that are produced by the same class of objects. Spallation by particles accelerated during gravitational events (SNII, SNIb/c) seems to be a likely origin. We show, in the context of a model of chemical evolution, that it is possible to solve the Li, Be and B abundance puzzle with the yields recently proposed by Ramaty et al. (1997), provided that SNII are unable to significantly accelerate helium nuclei and that different mechanisms are allowed to act simultaneously. 
C. Abia (Univ. Granada), J. Isern (I.E.E.C.), U. Lisenfeld (I.R.A.M.)