  The energy dissipated by virialization shocks during hierarchical structure
formation of the Galaxy can exceed that injected by concomitant supernova (SN)
explosions. Cosmic rays (CRs) accelerated by such shocks may therefore dominate
over SNe in the production of $^6$Li through $\alpha + \alpha$ fusion without
co-producing Be and B. This process can give a more natural account of the
observed $^6$Li abundance in metal-poor stars compared to standard SN CR
scenarios. Future searches for correlations between the $^6$Li abundance and
the kinematic properties of halo stars may constitute an important probe of how
the Galaxy and its halo formed. Furthermore, $^6$Li may offer interesting clues
to some fundamental but currently unresolved issues in cosmology and structure
formation on sub-galactic scales.
