phenomenon found in high-latitude cold regions is unexplained 

 horizons that may be clathrates, or crystalline gas hydrates, that 

 could form a new type of trap for oil and gas. Basic studies of 

 processes in deep sea deltas and trenches have indicated that large 

 deep sea reservoirs can form and that they may contain petroleum. 

 These deposits may provide future resources and an understanding 

 of them will provide a clearer understanding of petroliferous areas 

 now being explored. 



The trans-Atlantic Geotraverse (TAG) project of NCAA's 

 Atlantic Oceanographic Marine Laboratory is aimed at providing 

 knowledge of the geology and geophysical characteristics of a 3 

 degree corridor between Cape Hatteras and Cap Blanc, Mauritania. 

 This strip will be continuous with the crustal section already 

 established across North America by the U.S. Transcontinental 

 Geophysical Survey and will provide, for the first time, a standard 

 marine section to which other oceanic geophysical activities may be 

 related. 



Results to date have provided valuable information about the 

 ocean bottom that can be applied to research for subsea oil and 

 minerals. Preliminary work has already revealed the presence of 

 possible salt domes in the deep ocean basin off Cap Blanc. This is the 

 first region where possible salt domes were identified in the deep 

 ocean basin. If these are true salt domes, their presence would 

 indicate immense oil potential for the deep ocean basin. To date, only 

 the shallow continental shelves have been tapped for oil. 

 Additionally, a recent TAG cruise located the first hydrothermal 

 mineral deposit, of very pure manganese, ever discovered in a 

 median valley of a midocean ridge. These preliminary results would 

 indicate that the deep ocean basins are far richer in minerals than 

 previously suspected. 



In addition to its scientific significance, the ocean bottom plays an 

 important role in naval operations. The sea floor is a highly variable 

 and imperfect acoustic reflector and refractor. When the sea floor 

 acts as an acoustic boundary in sound systems, the behavior of the 

 sound propagation reflected off the sea floor or refracted through the 

 sedimentary and crustal layers must be known. In order to define the 

 acoustical properties of the sea floor and its deeper layers, a single- 

 ship technique using multifrequency sources, towed hydrophone 

 arrays, and expendable sonobuoys has been developed by Navy 

 researchers. Analysis of the data collected with these techniques 

 over all the major ocean basins of the world has identified the sound 

 velocity structure of the oceans' major sediment bodies. 



Results from these data are being used in acoustic propagation 

 models for system design and operational prediction. The theory of 

 sea floor spreading, which postulates that the earth's crust consists 



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