Table 3 



SUMMARY TABLE 



SHOWING POTENTIAL OF 



HARD MINERAL COMMODITIES FROM 



U.S. MARINE SOURCES (INCLUDING 



WATER COLUMN AND 



CONTINENTAL SHELVES AND SLOPES) ^ 



1. Chemical Constituents of Sea Water 



The mineral resources presently derived from 

 sea water-salt, magnesium, and bromine-are 

 present in sufficient concentration in the sea as to 

 be inexhaustible, and their production is limited 

 only by demand and by plant capacity. 



Table 4 lists data on the concentrations and 

 amounts of 22 elements and compounds in sea 

 water. 



The data show that the lithosphere's average 

 content of these common elements vastly exceeds 

 that of the sea for all the elements except sulphur. 

 The extremely low concentration of elements in 

 sea water is a major deterrent to commercial 

 production of minerals now obtained from rocks. 

 For example, the average yield of copper ores 

 mined today is 15,000 parts per million whereas 

 the sea contains only 0.003 part per million, one 5 

 millionth that of the lithosphere. The gross value 

 per cubic mile of sea water of 17 common 

 industrial elements, in most of which there is a 

 national shortage, is slightly less than $600,000. '^ 

 A plant to recover these 17 elements would have 

 to be about the size of the present Dow mag- 

 nesium plant at Freeport, Texas which pumps 

 about two milhon gallons per minute or about one 

 cubic mile per year. It is not economically feasible 

 to build and operate a plant of this size to recover 

 17 elements having a yearly gross value of only 

 $600,000. Important technological advances must 

 be made before elements other than those pres- 

 ently being recovered can be profitably extracted 

 from sea water. 



2. Submerged Placer Deposits 



The nature of submarine placer deposits is 

 described by Emery " as follows: 



Placer deposits are formed where streams or waves 

 and currents cause heavy minerals to be selectively 

 deposited in isolation from relatively worthless 



From deep sea floor the potential for manganese, cobalt, 

 copper, and nickel from manganese nodules is rated fair 

 to good. 



Calculated by CM. Shigley, Dow Chemical Com- 

 pany. The elements included are antimony, bismuth, 

 cadmium, chromium, cobalt, copper, gold, lead, manga- 

 nese, mercury, molybdenum, nickel, silver, tin, titanium, 

 uranium, and zinc. 



' 'k. O. Emery, "Geological Methods for Locating 

 Mineral Deposits on the Ocean Floor," in Exploiting the 

 Ocean (Washington, D.C.: Marine Technology Society, 

 1966), p. 27. 



VII-101 



