The geothermal mineral terraces at Mammoth Hot Springs in the north of Yellowstone National Park, were formed by heat, water, and limestone. They are best explored on foot. These geological features of the terraces have been described as resembling a cave turned inside out, and where the water trickles over the edges a frozen waterfall effect can be seen As ground water seeps slowly downward and laterally, it comes in contact with hot gases charged with carbon dioxide rising from the magma chamber.

Some carbon dioxide is readily dissolved in the hot water to form a weak carbonic acid solution. This hot, acidic solution dissolves great quantities of limestone as it works up through the rock layers to the surface hot springs. Once exposed to the open air, some of the carbon dioxide escapes from solution. As this happens, limestone can no longer remain in solution. A solid mineral reforms and is deposited as the travertine that forms the terraces.

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