SINKS
The most impressive sinks in the park, including Falling Water Sink, formed when the roof of an underground cavern or solution pipe collapsed. This caused the overburden sediments to slump into the cavity, opening a funnel, or a tube-shaped hole at the surface, and exposing the limestone bedrock in the walls of the sink. As the land surrounding Falling Water Hill was lowered by dissolution and erosion, the water table was also lowered sharply. The deep, tubular shape of Falling Water Sink may have been due, in part, to rapid downward dissolution in pace with the lowering of the ground water surface.
Many of the sinks in the area also take the form of coversubsidence sinkholes. In this type, a bowl-shaped depression in the earth occurs, which does not open into a hole.
The age of formation of the sinks is uncertain, but it has probably been a continual process for many thousands of years. Geologists believe that the ground-water table was considerably lower during the Pleistocene sealevel lowstands than it is today This may have left many of the formerly water-filled subterranean caverns high-and-dry, which, in turn, could have caused overburden collapse and sinkhole formation.
CAVES
Today, some of the caverns developed in the limestones under Falling Waters State Recreation Area are above the ground-water table, and contain dry, air-filled passages. Spelunkers, or cave explorers, have mapped two stretches of cave in the park. These are shown on the accompanying map. One is the cave which drains Falling Water sink. This cave extends westward nearly 80 feet from the opening in the base of the sink. Water flows along the floor of the cave and disappears under an impassable limestone wall.
A second, larger cave system runs under the walkway below the Falling Water sink overlook. It zig-zags some 400 feet southeast of the entrance sink, with connections to various small surface sinks. As you walk along the sink loop trail, you may observe cave entrances in some of the sinks. Please remember that the caves are off-limits to all but experienced spelunkers who have obtained permission from the Florida Park Service.