  We examine the qualitative features of parton production through
materialization in heavy-ion collisions within perturbative QCD, and estimate
the magnitude of the resulting parton density created during the early stage of
the collisions. The implications for ``anomalous'' $J/\psi$ suppression
observed in Pb+Pb collisions at the CERN SPS are discussed. We argue that the
A-dependence of absorption of $J/\psi$ by (partonic) comovers is steeper than
assumed in most phenomenological models, because the absorption process is
dominated by quasi-perturbative QCD interactions. Our argument is supported by
results recently obtained in the framework of the parton cascade model. We
predict significant ``anomalous'' suppression for Pb+Pb collisions at the
CERN-SPS, but not for S+U collisions.
