In Brevard and Volusia Counties the terraces and approximate elevations (in order of 

 decreasing age) are: Penholoway, 80 feet; Talbot, 50 feet; Pamlico, 25 feet; and Silver Bluff, 

 12 feet. (Wyrick, 1960.) Only the lower two terraces are germane to this report. They 

 represent the last two sea advances into the region; consequently, coastal sediments, 

 shoreline evolution, and shelf analogies may be related and better understood through 

 examination of their development. 



According to Cooke (1945), both the Pamlico and Silver Bluff terraces were formed 

 during brief transgressions associated with the Wisconsin glacial stage. As with the projected 

 ages of the higher, older terraces, the ages assigned by Cooke (1945), are debated by recent 

 investigators. Schnable and Goodell (1968), assigned the Pamlico terrace (25 feet) to the 

 Sangamon (last interglacial 80,000-120,000 B.P.) and the Silver Bluff (12 feet) to 

 mid-Wisconsin (30,000-40,000 B.P.). The age of the 25-foot terrace is ascribed by Alt and 

 Brooks (1965), to one or more, older interglacial: Yarmouth, 500,000 B.P. and Aftonian, 

 800,000 B.P. Contrasts in ages assigned to the 25- and 12-foot terraces by various 

 investigators working in different regions are largely a result of confusing stratigraphic 

 associations. Alt and Brooks (1965) and Osmond, May and Tanner (1970), show that these 

 conflicts may be due to repeated submergence and exposure of shell deposits and 

 reoccupation of old shorelines which would alter carbonates and anomalous carbon-14 

 dates. Reoccurring submergence and exposure may also cause cementation of shell deposits 

 at a time much later than original deposition of the shells, thus yielding inaccurate ages for 

 samples dated in toto. 



Sea level positions during the mid-Wisconsin transgression are not well known and thus 

 their effect on coastal morphology during this time cannot be established. Numerous 

 investigators have made an effort at resolving and providing insight into the problem of 

 mid-Wisconsin sea level positions. (Curray, 1965, 1969), (MilUman and Emery, 1968), 

 (Scholl and Stuiver, 1967.) Studies by Hoyt, Henry and Weimer (1968), and Hoyt and Hails 

 (1967), indicate that the sea invaded the Georgia coastal region at least twice during the 

 mid-Wisconsin. Further discussions and summaries of Pleistocene sea levels are contained in 

 Curray (1969), and Guilcher (1969). 



While it is not the intent of this study to evaluate the potential of onshore deposits for 

 borrow areas, these coastal terraces may be considered a future source for beach 

 nourishment materials. Samples of quartzose Pamlico sediments have a mean diameter of 

 0.21 mm (2.25 phi) and a standard deviation of 1.35 mm (0.44 phi); calcareous Silver Bluff 

 sediments have a mean diameter of —0.536 mm (0.90 phi) and a standard deviation of 

 2.12 mm (1.10 phi), a reflection of the coarse shell component. These size values, and the 

 proximity of the terraces to the shore make the terraces a feasible borrow source for beach 

 nourishment material. Economic practicality of using the terraces for a borrow source 

 depends on land values and transportation costs. 



(2) Canaveral Peninsula. Classically identified as a cuspate foreland (GuUiver, (1968), 

 and Johnson, (1919), Canaveral Peninsula is a prominent extension of the surrounding 

 adjacent Pleistocene coastline terrace complex. Aerial photos and topographic maps of the 

 peninsula reveal extensive rows of low linear ridges striking nearly parallel to the present day 

 coast as shown in Figure 3. The morphological pattern shown in the figure is interpreted as 

 sequential seaward building of a series of beach ridges. 



14 



