Scientists Decode the Origin of Mammoth Hot Spring Steps.

Scientists can now finally explain how the unusual steps at the Mammoth Hot Springs came to be:

Geologists have long been at a loss to explain the rocks’ unusual shapes, but physicists at the University of Illinois at Urbana-Champaign say they have figured out the answer.

Unlike most water-washed surfaces, the primary geological process shaping the Mammoth Hot Springs landscape is not erosion. The rocks there are actually growing — at the rate of one to five millimeters a day — as calcium carbonate in the water precipitates to form the mineral travertine.

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