unconsolidated placer deposits on beaches and the 

 continental shelf; and bedrock deposits in the 

 shelves. Current offshore mineral production on a 

 worldwide basis (exclusive of oil and gas) is more 

 than $700 milhon (Table 7) of which nearly $200 

 milhon, or about 30 per cent, is attributed to U.S. 

 offshore production. 



Throughout the world, more than 65 dredging 

 operations are currently exploiting such diverse 

 products as diamonds, gold, heavy-mineral sands, 

 tin, oyster shells, sand and gravel, and silica sands. 

 Of these commodities, sand and gravel are the 

 most important in terms of dollar value and only 

 sand and gravel and oyster shell is mined offshore 

 the United States. However, U.S. mining com- 

 panies are exploring for and extracting minerals 

 offshore in other parts of the world. Major 



land and Indonesia (the latter account for more 

 than 10 percent of the worlds's tin). Marine 

 diamond operations account for less than three 

 per cent of the total mineral values produced 

 offshore .^^ Although there currently is no off- 

 shore production of phosphate, extensive deposits 

 are known and exploration activities are progress- 

 ing in the more promising areas. 



A. Organization 



Most of the nearly 300 recorded worldwide 

 marine mining operations are being carried out on 

 an individual company basis. Some, particularly 

 those for coal, are Government operations; others 

 are consortium operations. There is no formal 

 trade organization for the ocean mining industry, 



Table 7 

 SUMMARY OF WORLD OFFSHORE MINING OPERATIONS 



(1966) 



Source: Charles M. Romanowitz, Michael J. Cruickshank, and Milton P. Overall, "Offshore Mining Present and Future,' 

 presented at IMSIA/OSTAC Ocean Resources Subcommittee Meeting, San Francisco area, April 26, 1967. 



offshore contributions to world production in 

 addition to sand, gravel, and shell include the 

 operations for heavy-mineral sands, mostly in 

 Australia, and offshore tin operations near Thai- 



M. J. Cruickshank, C. M. Romanowitz, and M. P. 

 Overall, "Offshore Mining Present and Future," Engi- 

 neering and MineralJoumal, January 1968. 



VII-108 



