IV-13 



(2) Cape Hatteras is a region where the deposition of 

 sediments on the wide shelf at the meeting place of two 

 major ocean currents has resulted in the building of a 

 series of barrier islands out over the shelf and the 

 formation of a wide shallow embayment (Pamlico Sound) 

 behind them (Figure IV. 1.4). This sedimentation process 

 has reduced the width of the continental shelf to less 

 than 20 miles at this point and created the infamous 

 Diamond Shoals seaward of the barrier islands. 



(3) South Florida, from Miami to beyond the Florida Keys, 

 has virtually no continental shelf; this is probably related 

 to the passage of the Gulf Stream through the narrow 

 channel between the Bahama Islands, Cuba, anu Florida 

 (Figure IV. 1.5). These same islands, however, serve to 

 protect the southern part of Florida from heavy ocean 

 swells, while the steady current keeps sediments from 

 depositing on the offshore coral formations of the Florida 

 Keys and tends to spread coral growth northward along the 

 Florida coast. 



(4) The Mississippi River, draining about 41 percent of 

 the continental United States, has built a delta entirely 

 across the continental shelf and now deposits most of its 

 sediments on the slope beyond (Figure IV. 1.6). The 

 generally enclosed nature of the embayment forming the 

 Gulf of Mexico has permitted the formation of this delta 



