During play, as far as I can tell, cracked sand only spreads on the surface; it represents dirt that has dried and become "useless".

But at generation, it goes deep to the stone.

Should it only generate as a top layer -- the grass only, instead of the dirt-and-grass?

It actually represents blighted land, like from radioactive fallout--but yes it should only be the top layer. This can be done most easily in the 3.0 series of releases.

On review, this can be fixed fairly easily. Milestone changed to reflect.