  We present deep WIYN H_alpha SparsePak and DensePak spatially-resolved
optical spectroscopy of the dwarf irregular starburst galaxy NGC 1140. The
different spatial resolutions and coverage of the two sets of observations have
allowed us to investigate the properties and kinematics of the warm ionized gas
within both the central regions of the galaxy and the inner halo. We find that
the position angle of the H_alpha rotation axis for the main body of the galaxy
is consistent with the HI rotation axis at PA = 39 deg, but that the ionized
gas in the central 20x20 arcsecs (~2x2 kpc) is kinematically decoupled from the
rest of the system, and rotates at a PA approximately perpendicular to that of
the main body of the galaxy at +40 deg. We find no evidence of coherent
large-scale galactic outflows. Instead multiple narrow emission line components
seen within a radius of ~1-1.5 kpc, and high [SII]/H_alpha ratios found beyond
~2 kpc implying a strong contribution from shocks, suggest that the intense
star formation is driving material outwards from the main star forming zone in
the form of a series of interacting superbubbles/shells.
  A broad component (100<FWHM<230 km/s) to the H_alpha line is identified
throughout galaxy disk out to >2 kpc. Based on recent work, we conclude that it
is produced in turbulent mixing layers on the surfaces of cool gas knots
embedded within the ISM, set up by the feedback from young massive star
clusters. Our data suggest a physical limit to the radius where the broad
emission line component is significant, and we propose that this limit marks a
significant transition point in the development of the galactic outflow, where
turbulent motion becomes less dominant. This mirrors what has recently been
found in another similar irregular starburst galaxy NGC 1569.
