The Pickaxe is used for mining in Night of the Dead. The resources you can gather with the Pickaxe are: Limestone, Boulder, Stone, Iron Ore, Iron Pieces, Copper Ore, Gunpowder. You could also use the pickaxe to kill zombies or fell trees. However it is not the right tool to do it efficiently. It is made for mining purposes and this is where it shines. To gather resources faster upgrading your Quarry Worker, Mine Worker and Mining Expert Perks in the Skilltree accordingly to your needs.