Adds Carbonate, oxide, sulfide, and fluoride minerals.
Mods introducing new content into the game.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Map generation and terrain modification.
New Ores and resources as well as machines.
Things related to oil and other fluids.
Furnaces, assembling machines, production chains.
Can I add this mod to current midgame save? Will this mod creane a patches only on undiscovered surface?
You can add it, but won't have extra ores spawned on nauvis. It won't crash your save, but you won't be able to utilize all of the mod's functions.