  The observations of the surfaces of the mid sized Saturnian satellites made
by Cassini Huygens mission have shown a variety of features that allows study
of the processes that took place and are taking place on those worlds. Research
of the Saturnian satellite surfaces has clear implications for Saturn history
and surroundings. In a recent paper, the production of craters on the mid sized
Saturnian satellites by Centaur objects was calculated considering the current
Solar System. We have compared our results with crater counts from Cassini
images and we have noted that the number of observed small craters is less than
our calculated number. In this paper we estimate the age of the surface for
each observed terrain on each mid sized satellite of Saturn. We have noticed
that since there are less observed small craters than calculated (except on
Iapetus), this results in younger ages. This could be the result of efficient
endogenous or exogenous process(es) for erasing small craters and or crater
saturation at those sizes. The size limit from which the observed number of
smaller craters is less than the calculated is different for each satellite,
possibly indicating processes that are unique to each, but other potential
common explanations would be crater saturation and or deposition of E ring
particles. These processes are also suggested by the findings that the smaller
craters are being preferentially removed, and the erasure process is gradual.
On Enceladus, only mid and high latitude plains have remnants of old terrains;
the other regions could be young; the regions near the South Polar Terrain
could be as young as 50 Myr old. On the contrary for Iapetus, all the surface
is old and it notably registers a primordial source of craters. As the crater
size is decreased, it would be perceived to approach saturation until D less
than 2 km craters, where saturation is complete.
