De or het mergelwinning?

The correct Dutch article is:

de mergelwinning

Rule Words ending in -ing: almost always de. See the rule

How to use mergelwinning

the mergelwinningde mergelwinning
this mergelwinningdeze mergelwinning
that mergelwinningdie mergelwinning
our mergelwinningonze mergelwinning
your mergelwinningjouw mergelwinning
every mergelwinningelke mergelwinning
which mergelwinning?welke mergelwinning?
a big mergelwinning / the big mergelwinningeen grote mergelwinning, de grote mergelwinning