  We analyse the geometry of the Pipe Nebula, drawn by the distribution
($Q$-spatial parameter) and hierarchy ($\Lambda$ spatial segregation) of column
density peaks previously detected and catalogued. By analysing the mass and
volume density of the cores, we determine that both variables shown to be
spatially segregated and with a high degree of substructure. Given the early
evolutionary state of the Pipe Nebula, our results suggest that both, mass and
volume-density segregations, may be primordial, in the sense of appearing in
the early phases of the chain of physical mechanisms which conform the
cluster-formation process. We also propose that volume density, and not mass,
is the parameter that most clearly determines the initial spatial distribution
of pre-stellar cores.
