Terrigenous fraction of the Type A sand is derived ultimately from the complex 

 metamorphic rocks of the southeastern United States as shown by Pilkey (1963, 1968). 

 Paucity of heavy minerals and feldspar suggests that the sediment has undergone one or 

 more previous stages of deposition, erosion and transportation. Calcareous fraction contains 

 both modern shells formed and deposited under conditions similar to those at present and 

 older reworked biogenic grains from underlying sediments. Evidence for derivation of 

 Type A sands from older underlying sediments (mainly Type E) is the presence of fauna not 

 indigenous to the survey area, such as lagoonal species, and of the small percentage of oolitic 

 grains. Ooids are not forming in this area at present and those in surface deposits resemble 

 Type E ooids in size, nucleii, and degree of completeness. Figure 22 shows the occurrence of 

 ooids in beach, shoal and subsurface deposits. The ooids are from Type E sediment; 

 elsewhere, the occurrence of ooids impUes that erosion and reworking ar& taking place. 



e. Beach Sediments. Beach sands in the Cape Canaveral region are derived and 

 maintained by lateral transport of Uttoral currents and by onshore transport from optimum 

 wave conditions. Florida rivers are near grade and are not effective conduits of sand to the 

 Atlantic Ocean. Effect of transport by the larger Georgia rivers which drain the Piedmont 

 Province is unknown. Sediments transported into the region by httoral processes are from 

 erosion of Volusia County beaches and the coastal formations which occasionally crop out 

 on the beach, in the littoral zone and offshore. Sediments delivered to the beaches from 

 offshore originate from modern biogenic production and bottom erosion. Storm deposits of 

 organisms living on the shoreface periodically nourish the carbonate fraction of the beach 

 sands. Onshore transport of Type A sand is inferred from the similarity of beach sand and 

 Type A shelf sand. Especially indicative of this mode of supply is the presence in all Cape 

 Canaveral beach sands of oolitic grains, which are exclusively from offshore sources. (Pilkey 

 and Field, 1972.) 

 2. Quaternary Development of the Inner Shelf. 



The marked influence of eustatic sea-level fluctuations associated with Pleistocene 

 glaciation is evident in the subbottom geologic record of the Cape Canaveral area. 

 Undulatory tertiary strata (green horizon) are evident only below 160 feet. (See Figure 7.) 

 Above this depth, strata bear evidence of having been truncated and buried through 

 terrestrial and marine processes acting in response to fluctuations of sea level. The red 

 horizon (Fig. 6) probably represents the lowermost surface cut by Pleistocene seas. 

 Interpretation of the geologic history of the upper subbottom (20 feet) is simpUfied and 

 faciUtated by the recovery of subsurface core samples. Ages of the upper subbottom units 

 are schematized and correlated to eustatic events in Figure 23. 



The yellow horizon is a shallow mappable surface lying an average of 80 feet below the 

 sea floor and dipping at an angle slightly greater than the sea floor. A lack of samples from 

 the yellow surface precludes analysis of its characteristics or origin. However, two samples 

 from just above the yellow horizon indicate that the surface is as old as the Sangamon 

 interglacial, and probably was formed during the regression or transgression associated with 

 that time. Shotton (1967) places the midpoint of the Sangamon (last) interglacial at about 

 105,000 B.P. In situ plant debris having a radiocarbon age of 39,000 B.P. (core 185) 

 indicates sediments of the underlying yellow layer are at least that old. A large shell 

 (Mercenaria and campechiensia) obtained from core 178 at —8 feet is altered to chalk with 

 occasional 0.5-mm crystals of calcite on the exterior and in boring and solution cavities, 

 indicating exposure of the shell to subaerial conditions. 



50 



