(3) Area A-10. The surface sand in core 173 from this long narrow ridge (Fig. 42) is 

 a clean medium quartz sand ranging from 0.233 to 0.308 miUimeters (1.7 to 2.1 plii) mean 

 diameter. Below about —2 feet, similar but shghtly silty sand extends to —7 feet. The 

 quality of the material in this area does not appear to be as good as sand in areas A-8 and 

 A-9. The ridge is judged to contain about 5 X 10^ cubic yards of sand of which about 

 1.5 X 10^ cubic yards are probably well suited for beach fill. 



(4) Area B-8. This area consists of a crook-shaped low ridge. Core 133 near the 

 inshore flank of the ridge contains fine slightly silty sand. It is not known if this sand is 

 typical of the ridge sediments. 



(5) Areas B-9, B-10, B-11, B-12, B-13, B-14, B-17, and B-18. Although there are no 

 cores in tliese linear, roughly north-south trending shoals, they are morphologically similar 

 to hnear accretionary shoals off Fort Pierce and Cape Canaveral (and elsewhere on the East 

 Coast Shelf) which are formed of clean medium to coarse sand. Further, three other Unear 

 shoals (Areas A-8, A-9, and A-10) near these features were cored and found to contain sand 

 suitable for nourishment and maintenance of beaches within the nearby coastal area. 

 Therefore, it is considered Ukely that areas B-9, B-14, B-17, and B-18 contain usable sand 

 and further investigation is warranted. The B-11 shoal is a particularly good prospect since it 

 appears continuous with area A-9 where presence of suitable sand is supported by core data. 



(6) Areas B-15 and B-16. These two large flat-topped irregular shoals were not cored; 

 however, clean medium sand occurs in cores 160 and 152 at the edge of the shoals. The 

 deposit may be thicker on the shoal proper; if so it would be suitable for borrow sites and 

 would contain large volumes of sand. 



VI. SUMMARY 



Survey of the north Florida Atlantic inner Continental Shelf was undertaken to obtain 

 data on inner shelf morphology, shallow structure, sediments, and sand resources. During 

 the survey, 1,153 nautical miles of seismic reflection Line were run and 197 cores up to 15.5 

 feet long were collected from the study area. 



The Atlantic coast of Florida north of Cape Canaveral is a low coastal plain modified by 

 relict terraces and beach ridges of Pliocene-Pleistocene age. Well developed modern beaches 

 fringe the shorehne throughout the region; lagoons or marshy lowlands commonly he inland 

 of the beach. 



The East Coast Shelf off northern Florida is a submerged coastal plain with a very gentle 

 seaward slope and subdued topography. The most prominent topograpliic feature of the 

 inner shelf is the shoreface slope which decends to depths of 45 to 55 feet generally within 

 1.2 nautical miles of shore. Elsewhere the inner shelf contains linear and irregular highs and 

 broad, Unear depressions. These features are generally of low rehef and many may be related 

 to a relict subaerial drainage system. 



A thick section of Cenozoic sedimentary rocks dipping generally eastward underUes the 

 Atlantic coastal zone of northern Florida. The stratigrapliy of these rocks is not well known 



97 



