  We introduce the Dirac eigenmode filtering of topological charge density
associated with Ginsparg-Wilson fermions as a tool to investigate the local
structure of topological charge fluctuations in QCD. The resulting framework is
used to demonstrate that the bulk of topological charge in QCD does not appear
in the form of unit quantized lumps. This means that the mixing of "would-be"
zeromodes associated with such lumps is probably not the prevalent microscopic
mechanism for spontaneous chiral symmetry breaking in QCD. To characterize the
coherent local behavior in topological charge density at low energy, we compute
the charges contained in maximal coherent spheres enclosing non-overlapping
peaks. We find a continuous distribution essentially ending at ~0.5. Finally,
we study, for the first time, the overlap-operator topological-charge-density
correlators and find consistency with non-positivity at nonzero physical
distance. This represents a non-trivial check on the locality (in gauge paths)
of the overlap Dirac operator for realistic gauge backgrounds.
