  The recent observations of microlensing events in the LMC by the MACHO and
EROS collaborations suggest that an important fraction of the galactic halo is
in the form of Massive Halo Objects (MHO) of about 0.1 M_{\odot}. Here, we
argue that the galactic halo is mainly baryonic and that besides MHO also H_2
molecular clouds may significantly contribute to it. We propose a scenario in
which dark clusters of MHO and/or H_2 molecular clouds form in the halo at
galactocentric distances larger than ~ 10-20 kpc, since there we expect less
collisions among proto globular cluster clouds and a smaller UV radiation flux.
Cosmic ray protons may induce a significant gamma-ray flux in H_2 molecular
clouds. Our calculation gives an upper bound to this flux which is below
present detectability.
