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Gulf of Mexico Tidal Wetlands

A Photo Gallery of Florida's Big Bend Tidal Wetlands

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Ellen Raabe


Gulf of Mexico Bathymetric Map
location of Florida's Big Bend

  Limestone outcropping karst
Florida rests on a wide shallow limestone shelf that extends offshore in the Gulf of Mexico. The resulting gradient creates a low energy system unusual in open coastal environments. This low gradient supports the development of extensive tidal marshes along Florida's Big Bend.

The carbonate limestone shelf weathers unevenly leaving a pockmarked surface called "karst." Areas of exposed karstified limestone are found throughout the marsh of Florida’s Big Bend coast. Marsh sediments fill the pockets of exposed limestone, providing a foothold for colonization by salt-tolerant species such as pickleweed and glassworts.

Freshwater from the Floridan aquifer seeps through fractures and dissolution channels in the limestone. Sinkholes are created when underground karst features collapse.

fracture pattern in exposed limestone
Fractures in limestone
freshwater sinkhole in tidal marsh
Freshwater sinkhole pond

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Coastal and Marine Geology Program > St. Petersburg Coastal and Marine Science Center > Gulf of Mexico Tidal Wetlands > Photo Gallery > Geology

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Updated January 04, 2013 @ 10:28 AM (THF)