Tag Archives: flowstone

Geopic of the week: Travertine falls

Travertine Fall over St. Peter ss, Searcy County

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

Geopic of the week: Speleothems

 

Geopic Blanchard

Above are speleothems- they’re also called dripstones, stalagmites and stalactites, or other names depending on their shape.  They can be seen when touring Blanchard Springs Caverns located about 10 miles north of Mountain View, Arkansas.  The cave is full of breathtaking features like these which form by precipitation from ground water that drips from the cave ceiling.  The groundwater, which has traveled through rock and soil before reaching the cave, is saturated with minerals it dissolved along it’s path.  The principal mineral that forms the dripstones is calcite.  As the groundwater enters the open air of the cave a pressure drop causes the calcite to come out of solution and precipitate a tiny coating on the outside of the growing speleothem.  Over time some of them can reach from the roof to the floor of the cave and elaborate, and marvelous shapes develop.