Post-Miocene history has resulted in numerous depositional sequences and erosional 

 surfaces formed as a response to fluctuations in sea level. Multiple eustatic changes are 

 judged the primary agent responsible for the existing land and Continental Shelf 

 topography. Secondary agents of landform modification have been dissolution and 

 dissection of the exposed limestone surface, accretion of modern sediments in lagoons, and 

 modification and accentuation of shallow water features by normal marine processes. 



b. Regional Marine Geology. The Florida Continental Shelf is the southernmost part of 

 the East Coast Shelf (name proposed by Uchupi, 1968) and is bound on the north by the 

 broad Georgia Shelf, on the south by the Straits of Florida and on the east by the steep 

 Florida-Hatteras Slope. (See Figure 1.) Seaward of the Florida-Hatteras Slope is the broad 

 flat platform of the Blake Plateau. The shelf in this region is composed of strata lying at low 

 angles and dipping generally easterly and southeasterly. Slope of the shelf increases rapidly 

 in a southern direction from 1 on 1,750 at Jacksonville to 1 on 200 at West Palm Beach. 

 (Uchupi, 1968.) A marked narrowing of the shelf from north to soutli Florida accompanies 

 this increase in gradient. Shelf width is about 82.5 miles at Jacksonville (30°30'N.) and 

 steadily narrows to 2 miles at West Palm Beach (27°00'N.). (Uchupi, 1968.) The shelf at 

 Cape Canaveral is about 32 miles wide and dips seaward at about 1 on 440. 



Geology of the East Coast Shelf is well known relative to other shelves of the world. 

 (Emery, 1969.) Structure, age, physiography, and sediment cover have been charted and 

 described by many investigators in abundant hterature during the past several decades. In 

 particular, the works of Stetson (1938), Tyler (1934), Gorsline (1963), Curray (1965), 

 Emery (1965), Pilkey and Field (1972), Pilkey (1968), Uchupi (1968, 1969), Maclntyre and 

 MiUiman (1970), MiUiman (1972), have discussed regional aspects of the marine geology of 

 the southeastern U.S. Continental Shelf. These investigators have charted bottom 

 morphology, described textural and compositional parameters of the surficial deposits, and 

 related these parameters to bathymetry, sediment sources, and shelf history. While these 

 studies provide useful background material, the low density of samples, methods of 

 sampling (surface grab) and areas of study (usually deeper parts of the central and outer 

 shelf) limit their use for delineation of smaller sediment bodies within the bounds of this 

 survey. 



c. Coastal Morphology and Evolution. 



(1) Coast Terraces. Morphology of peninsular Florida is dominated by a number of 

 terraces aUgned roughly parallel with the present coastlines. The terraces have long been 

 recognized and their general characteristics are well documented. (Cooke, 1945), 

 (Altschulter and Young, 1960), (Alt and Brooks, 1965), (Schnable and Goodell, 1968.) 

 Most agree on the related positions and ages of the terraces; older terraces are higher and 

 farther inland than younger ones. The Florida coastal terraces are similar to the isostatie reef 

 terraces of Barbados described by Mesolello, et al., (1969) and the coastal terraces and 

 plains from other regions of the world. (Donovan. 1962), (Oaks and Coeh, 1963.) 



The absolute age or exact number of the Florida terraces is not well established. Cooke 

 (1941, 1945) identified four terraces in Florida on a topographic basis and assigned them to 

 interglacial periods of the Pleistocene. However, the interpretation of coastal terraces as 

 being solely a product of Pleistocene eustatic events has long been debated. (Flint, 1940, 

 1941), (Cooke, 1941.) Using stratigraphic data rather than topographic control, Altschulter 

 and Young (1960) and Alt and Brooks (1965) have suggested that the oldest terraces may be 

 late Tertiary and only the lower terraces were formed during the Pleistocene. 



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