Pictured above is a travertine falls. It looks like a waterfall except that, rather than being water, it’s composed of solid rock.
Travertine is made of calcite which also forms stalactites and stalagmites. Like those familiar cave features, travertine falls form by precipitation from water; the water is flowing in a creek, over a ledge instead of dripping from a cave ceiling. As the travertine precipitates in layer upon layer, it begins to take on the appearance of flowing rock.
Dripstone features like these only form in areas where the groundwater carries a high load of dissolved carbonate minerals. This one was photographed in Searcy County, Arkansas, not far from the Buffalo National River, near the contact between the St. Peter and Plattin Formations.
For another view of this travertine falls click here