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GENERAL 

How to get access to the Cave
How to be a Good Guest
Where is Bat Cave?

The AREA 

The Geologic Time Scale 
Area rock Layers
Topography 
Geomorphology
Geological History 
          The Paleozoic
          The Mesozoic
          The Cenozoic
Water
The Hydrologic Cycle
Solution
Solution chemistry
Karst Landscapes
Erosional Features 
Depositional Features
Environmental Issues 

BAT CAVE

What is a cave?
How was Bat Cave formed?
Surface Plan of the site
Map of the Cave
Life in and around Bat Cave
A Virtual Trip Through Bat Cave

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 TYPES OF FLORIDA SINKHOLES
There are basically four (4) different types of sinkholes in Florida. 
1. Collapse sinkholes
This occurs in areas where there is extensive cover materials over a limestone layer. When solution creates a hole in the limestone and the limestone roof over the cavern either dissolves or no longer can support the weight of the overlying materials, these cover materials collapse into the cavern, leaving a funnel shaped sinkhole, usually circular in outline. In sands, these funnels will have gentle slopes, while in cohesive clays or in rock, the sides will be nearly vertical. If the overlying cover is clastic sediments it is called a cover collapse sink. If it is limestone, it is a rock collapse sink. The best known example of  a rock collapse sink is the Devil's Millhopper State Geologic Site near Gainesville.  Commonly, the formation of collapse sinkholes is sudden and catastrophic. These collapses are often affected by human activity, especially those that affect the hydrology of an area. 

2. Solution Sinkholes
These sinkholes form more slowly and gradually as a result of enlargment of joints by solution. Eventually the rocks may settle and the cover material washes into the cavern in a process called raveling. These sinks are not as potentially impacted by human activities as are collapse sinkholes. Most commonly, it is changes in  the hydraulic conditions in the aquifer (either natural or man-induced) that lead to raveling and solution sinkhole activation. 

3. Alluvial Sinkholes.
Older sinkholes partially or entirely filled with sediments due to subsequent marine deposition or by materials washed in from the sides are called alluvial sinkholes. Where the water table is shallow, they are often indicated by ponds, wetlands or cypress domes. 

4. Raveling sinkholes
The above alluvial sinks may become reactivated when the aquifer levels rise or drop. Lowering of the aquifer levels creates a loss of buoyant support;  increasing the water content of the plug such as happens when the water levels rise, increases the load and decreases the cohesion of the sediments. Other factors also come into play: vibrations, pucturing the plug with a well or other activity may cause the plug to fail by erosion and upward piping failure. When the sediments are no longer supported,  the plug rapidly collapses. 
 
Effects on the Landscape
These many cycles of exposure and covering and mixing due to changes in sea level stands have led to repeated cycles of karstification. Virtually all carbonates (at least those deposited after the Late Cretaceous on) contain solution features.  Karstification is more extensive during low stands of sea level and more limited during high stands. We know that there were major variations in sea level in the Late Oligocene and Miocene, especially in the Messinian (Latest Miocene). Some karst features extend well below sea level (up to 800').  The only way of dating karst features is by the fossils they contain, and that only gives us a minimum age. Vertebrate fossils contained in solution features range in age from Oligocene to Recent.

Most sinkholes occur along the sides of the Ocala Platform. The greatest correlation exists between cover type and thickness. Rock collapse ans solution types are most likely where the cover is thin to non-existent. With thicker cover, cover collapse and rejuvenated alluvial sinks (raveling sinks) are more common. Where the cover is very thick there are almost no sinks that develop. There is also a direct correlation between ancient and modern sinks. As can be expected new ones will form in the same area as ancient ones.