INTERNATIONAL DECADE OF OCEAN EXPLORATION SEABED ASSESSMENT 



MANGANESE NODULES Of 

 ABYSSAL PLAINS iNiXu.Co ETC 



HEAVY MINERAL DEPOSITS 

 ON ANCIENT STRAND LINES 



OIL & GAS PROVINCES ON 

 THE CONTINENTAL MARGINS 



HEAVY MINERAL 

 CONCENTRATION ALONG 

 RIFT VALLEYS 



IDCE 73-635 

 n-7-72 



Artist's conception of the major areas of concentration for the IDOE Seabed 

 Assessment Program. 



Understanding the origin of metalliferous ores and metal-bearing 

 sediments is the goal of IDOE projects on active spreading zones in 

 the deep ocean, including the mid-Atlantic Ridge and the East Pacific 

 Rise. In the Nazca Plate region off the west coast of South America, 

 the complex interrelationships between sea and land geology appear 

 to produce metallogenic zoning of copper, zinc, and tin. Highly 

 metalliferous sediments, a potential source of heavy metals, have 

 also been identified in the Bauer Basin located near the East Pacific 

 Rise. Detailed studies found that these sediments may consist of 

 distinct manganese-or iron-rich phases, as well as nickel and cobalt. 



Similar work on the mid-Atlantic Ridge involves use of 

 submersibles for direct observations of geological processes in the 

 rift valley. Preliminary site surveys and initial dives by French 

 submersibles were completed during the summer of 1973. Joint 

 operations by French and U.S. scientists will be conducted in 1974 as 

 part of the French-American Mid-Ocean Undersea Study 

 (FAMOUS] (App. Cj. 



The formation and location of manganese nodules has been the 

 focus of a major seabed assessment program. A series of maps 



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