os79
Deity
Are there units at the end of the tech tree that can be built without any mine/quarry resource? If no, you're creating a situation where instead of reaching for the stars, everyone will be necessarily go back to fighting with pointy sticks. I'm dubious about solar power, but at the least there should be a series of 'solar-powered' non-resource requiring units. Or some form of recycling (maybe national wonders?) that provide most of those resources late in the game.
Honestly, we shouldn't ever run out of stone, and we can get salt just by letting sea water evaporate. And if we ever literally ran out of iron or copper underground, some one would start digging up landfills. Uranium is more problematic, but we use less of it any given time-I don't think I've ever seen concern expressed that we might burn through the worlds radioactive materials. And there are experiments not that demonstrate we can produce oil by subjecting biological waste (inedible chicken parts, but I think any such material would work) to heat and pressure.
Yeah, but the oil is what is causing Global Warming in this day and age. So, I doubt strongly that humanity would even want to produce more oil synthetically after they figure out the technology for an effective green energy.