Travertine Precipitation.
According to the Yellowstone National Park Service (NPS), the Mammoth Hot Springs area is continually being shaped by unique geothermal processes. These processes start as ground water seeps slowly downward and comes in contact with hot carbon dioxide filled gases rising from Yellowstone’s magma chamber. The carbon dioxide is then dissolved in the hot water to form a weak carbonic acid solution. This solution then aids in dissolving limestone as it works its way towards the surface. Once this solution is exposed to open air, carbon dioxide is released and a solid mineral reforms and is deposited as Travertine. It is this Travertine that forms the terraces at Mammoth Hot Springs.
This is a compelling example of real world phenomena that provides opportunities for debate on chemical versus physical geothermal changes in nature. Location: Yellowstone National Park. Author: Karl Spencer.