  If the dark matter of our galaxy is composed of nuggets of quarks or
antiquarks in a colour superconducting phase there will be a small but non-zero
flux of these objects through the Earth's atmosphere. A nugget of quark matter
will deposit only a small fraction of its kinetic energy in the atmosphere and
is likely to be undetectable. If however the impacting object is composed of
antiquarks the energy deposited can be quite large. In this case nuclear
annihilations within the nugget will trigger an extensive air shower the
particle content of which is similar to that produced by an ultrahigh energy
cosmic ray. This paper gives a qualitative description of the basic properties
of such a shower. Several distinctions from an air shower initiated by a single
ultra high energy nucleus will be described allowing these events to be
distinguished from the cosmic ray background. The subtlety of these features
may mean that some fraction of the high energy cosmic ray spectrum may in fact
be due to this type of dark matter interaction.
  The estimated flux of dark matter nuggets and the energy deposited in the
atmosphere are such that the Pierre Auger Observatory may prove an ideal
facility to place constraints on the flux of heavy quark matter objects. This
paper attempts to highlight the best techniques to search for a quark matter
signature through an extensive air shower signal.

High Energy Astrophysical Phenomena;High Energy Physics - Phenomenology