An estimated 95% of the surface waters in northeastern Florida are sinkholes (Brainard, 1982; Lane, 1986). The lakes originate from the direct result of chemical and/or mechanical processes. The mechanical processes that result in lake development are: 1) slumping or subsidence of underlying clastic or carbonate sediments; 2) clustering of sinkholes; or, 3) a combination of the previous two. Sinkhole lakes in Florida occur in areas of thin overburden, typically less than 61 m (100 ft). In areas with an impermeable confining layer and no breaches, a lake might be a perched lake (the lake level is held above the groundwater level) with no communication with subsurface aquifers. Otherwise a lake will form in conditions where a lack of overburden or permeable confining layer allows for increased karstification of the underlying limestone, producing a depression due to limited fill material.
Artifically-induced causes for increased karst development.
The seismic profiles indicate that sinkhole lakes can be delineated into a progressive sequence of lake evolution based on geomorphic types (Kindinger and others, 1999) (Fig. 13). In central Florida the progression begins with the subsurface dissolution of the limestone host rock (see Karst Development), ultimately leading to surface collapse or subsidence. The depression may be dry or, if a portion is below the water table, it may contain water. Erosion of sediments into the depression may cause the sinkhole to become plugged. Further erosion may eventually bury the sinkhole.