There are also biomes, called zones. The mod currently features three zones.
Rock zone – this zone resembles regular cave. Ores don’t spawn in veins, but as single blocks. They are not limited by height. Remoted sheds and ancient ruins are lying in the deeps and stalactites and stalagmites can be found all around.
Snow zone – dead, snow-covered wasteland. Ores are burried deep in snow(in the same fashion as in rock zones), icicles hang from the ceiling and noone lives here except for monsters haunting this frozen hell. However, adventurer brave enough can find and rob big dungeons with exclusive loot. If he doesn’t get killed first, of course.
Jungle zone – Walls here are made of sticky moss-covered stone. Giant roots of ancient trees grow here more than anywhere else. You cannot find any ores here at all. You can sometimes encounter remoted shack.