How exactly does carbonated water form in nature?

Question

No web site, to my knowledge, explains the formation of natural carbonated water. Apparently it has something to do with calcite or similar rocks, and a change in pressure (which brings out the bubbles). Beyond that, I can't find any details, such as specific springs and how they work, or how much CO2 you can actually get naturally in water.

Answer 1

Water under pressure (i.e. deep underground) can dissolve large amounts of CO2 if there is CO2 around then the water will become carbonated.