  The characterisation of galaxy-scale outflows in terms of their multi-phase
nature, amount, and effects of flowing material is crucial to place constraints
on models of galaxy evolution. This study can proceed only with the detailed
investigation of individual targets.
  We present a spatially resolved spectroscopic optical data analysis of Mkn
848, a complex system consisting of two merging galaxies at z~0.04 that are
separated 7.5 kpc (projected distance). Motivated by the presence of a
multi-phase outflow in the north-west system revealed by the SDSS integrated
spectrum, we analysed the publicly available MaNGA data, which cover almost the
entire merging system, to study the physical properties of cool and warm gas in
detail.
  Galaxy-wide outflowing gas in multiple phases is revealed for the first time
in the two merging galaxies. We also detect spatially resolved resonant NaID
emission associated with the outflows. The derived outflow energetics may be
consistent with a scenario in which both winds are accelerated by stellar
processes and AGN activity, although we favour an AGN origin given the high
outflow velocities and the ionisation conditions observed in the outflow
regions. Deeper observations are required, however, to better constrain the
nature of these multi-phase outflows. Outflow energetics in the north-west
system are strongly different between the ionised and atomic gas components,
the latter of which is associated with mass outflow rate and kinetic and
momentum powers that are 1-2 dex higher; those associated with the south-east
galaxy are instead similar.
  Strong kp-scale outflows are revealed in an ongoing merger system, suggesting
that feedback can potentially impact the host galaxy even in the early merger
phases. The characterisation of the neutral and ionised gas phases has proved
to be crucial for a comprehensive study of the outflow phenomena.
