  One of the abiding mysteries in the so-called standard cosmological model is
the nature of the dark matter. It is universally accepted that there is an
abundance of matter in the universe which is non-luminous, due to their very
weak interaction, if at all, with the other forms of matter, excepting of
course the gravitational attraction. Speculations as to the nature of dark
matter are numerous, often bordering on exotics, and searches for such exotic
matter is a very active field of astroparticle physics at the dawn of the new
century. Nevertheless, in recent years, there has been experimental evidence
for at least one form of dark matter - the massive compact halo objects
detected through gravitational microlensing effects proposed by Paczynski some
years ago. To date, no clear consensus as to what these objects, referred to in
the literature as well as in the following by the acronym MACHO, are made of;
for a brief discussion of some of the suggestions, see below. In this work, we
show that they find a natural explanation as leftover relics from the putative
first order cosmic quark - hadron phase transition that is predicted by the
standard model of particle interactions to have occurred during the microsecond
epoch of the early universe.
