60 140 120 100 80 60 40 20 20 40 60 80 100 120 140 160 180 



Figure 2. Distribution of upwelling water and related phenomena in modem oceans (modi- 

 fled Brongersma-Sanders, 1957, to include data on the distribution of phosphate deposits). 

 Source: V.E. McKelvey and Livingston Chase, "Selecting Areas Favorable for Subsea Pros- 

 pecting," in Exploiting the Ocean (Washington, D.C. 20005: Marine Technology Society, 

 1966). 



averages over 31 per cent. Phosphate for fertilizer manufacture must contain a minimum of 31 per cent 

 P2OS and if it contains less than that it must be beneficiated, a process that is difficult when the 

 phosphatic nodules or pellets contain less than that amount. CoDier Carbon and Chemical Company 

 attempted to recover nodules from a deposit on Coronado Bank in this area in the early 1960's but was 

 forced to abandon it because of the presence of an associated naval ordnance dump. 



Phosphorite nodules and slabs are also found off the Atlantic coast in waters 600-1,600 feet deep. 

 They are most abundant and richest on the .1 degree slope extending from the outer edge of the 

 Continental Shelf off Florida down to the Blake Plateau.^ '' These contain on the order of 20 per cent 

 P2 Oj . Phosphorite nodules also occur on the upper thousand feet of the continental slope as far north as 

 New York, but the nodule concentrations seem to decrease markedly in a northward direction. 



In addition to phosphorite nodules, three other types of marine phosphatic deposits are known: 

 phosphatic sands, pelletal phosphatic muds, and consolidated phosphatic beds of Tertiary age. 

 Phosphatic sands occur up to 75 miles off the coasts of Georgia and the Carolinas in water depths 

 ranging up to 600 feet and in concentrations of one to eight per cent Pj Oj } * An area of relatively high 

 concentration 10 miles long and three to four miles wide lies in 60 to 100 feet of water about 10 miles 

 off Cape Fear. This deposit may contain four million tons of P2O5 at an average concentration of 4 to 6 

 per cent.^ ' 



'k. O. Emery, "Some Potential Mineral Resources of the Atlantic Continental Margin," in Geological Survey 



Research 1965, Geological Survey Professor Paper 525-C, pp. C-157-C160, 1965. 



^^D. R. Peaver and O. H. Pilkey, "Phosphorite in Georgia Continental Shelf Sediments, 



Bulletin, Vol. 77, No. 8, pp. 849-858, 1966. 



29 



Ocean Science and Engineering, Inc. report. 



' Geology Society of America 



VII-145 



