Quarries and Mineshafts

[CosmicKobal]

I want to say that I've seen quarries and mines done in various ways by various mods, but I can't honestly remember the particulars of them. I do feel like there should be a renewable source for stone and metal though. perhaps requiring 10 wood or so for each 'USE' of the mine or quarry to represent the resources needed to hold up tunnels and retaining walls. It might be best to only have a percent chance of success in finding usable stone or metals though, that way it's not just a straight trade of wood for metal/stone.

Any thoughts?