water. These nodular masses were more resistant and the less-resistant, usually softer limestone has been removed from about them, leaving the form resembling a duck. Several stalagmites are in the background. These are younger than the “duck.”" tag="{http://www.w3.org/1999/xhtml}img"/>

The “duck” results from irregular resistance of the limestone to solution by ground water. These nodular masses were more resistant and the less-resistant, usually softer limestone has been removed from about them, leaving the form resembling a duck. Several stalagmites are in the background. These are younger than the “duck.”

Since emerging from the sea for the last time, this part of Florida about the state park area has been undergoing changes constantly. The rocks have been continuously attacked by elements of the weather, and disintegrated where exposed. Running streams carry away much of these products of weathering, but the work of water under the ground is the major factor in the creation of these caves and the deposits in them. This underground water, running through the pores in the limestone, has been and is now wearing away portions of the land. These water channels are isolated along fractures, bedding planes and other structural weaknesses, or along poorly consolidated rock. The water dissolves the limestone and carries it out into surface streams and on to the sea, and as this material is carried away the rock, through which the water flowed to the surface, is being worn away an equal amount. The amount of this material being carried away is illustrated at Silver Springs, one of our larger springs, where each day about 450 tons of rock is carried away dissolved in water. When it is realized that this is only one of thousands of springs in Florida, you can readily see what a large amount of rock is being dissolved from beneath the ground and just how cavernous the rock must be.

Ground water cascading down a gentle limestone face was ponded irregularly and the evaporation of the water along the outer edges formed small terraces.

Solution of Limestone

The rocks in which the caves of the Florida Caverns State Park were formed are limestone. This rock is made of the mineral calcite, calcium carbonate, and it is soluble in pure water under conditions of favorable structure, a continuous supply of moving water and time. However, in the water of Florida this limestone is readily dissolved, because the humid climate and prolific vegetation contribute organic and mineral acids to water and make it a highly potent solvent that is capable of dissolving large amounts of this rock.

Limestone is as a rule jointed vertically and bedded horizontally. Openings along these joints and beds provide easy avenues of travel for water. The ultimate source of all of Florida’s ground water is from the rain and precipitates from the air. As this rain water falls through the air it becomes charged with carbon dioxide gas which combines with water to form carbonic acid. On the ground humic acids from rotting vegetation is added. These are the common natural solvents of limestone. A good portion of this acid charged water soaks into the ground, and as it descends through lime rock small portions of the rock are dissolved. However,