An Oceanic Quest The International Decade of Ocean Exploration. (1969) / Chapter Skim
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Pages 59-64
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From page 59... ...
isolated from the Atlantic. Salt deposited at this time has since risen as domes and anticlines, piercing the overlying sediments; as on the continents, the turned up edges of the pierced sediments form excellent petroleum traps.
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From page 60... ...
that attempt to explore the underlying causes for the plate motion. Although the motion away from the mldocean spreading axes is well established from the magnetic anomalies, details of both volcanic and tectonic events at the axis of spreading are l i t t le known.
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From page 61... ...
Convergences in the plate motion zones of trenches and young mountains have been less studied, although in terms of human interactions with volcanoes, earthquakes, and mineral resources they may be far more important. For example, the continental shelf facing a deep trench is sometimes petroleum-rich, but the accumulations are a very special class of intensely normal-faulted o i l f ie lds .
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From page 62... ...
returned from the sea floor to the mantle. The sodium balance has been particularly unsatisfactory.
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From page 63... ...
the Andes. Not only are the volcanic rocks of the last several years avai l able for study in the Andes, but the major canyons cut completely through the volcanic pile to a pre-volcanic basement.
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From page 64... ...
As a complement to this continental margin study, studies of a purely oceanic trench or trenches would be useful . Both the on-going work by Lament and Scripps on the Tonga-Kermadec trench and the proposed US-USSR study of the Aleutian arc should be identified as important contributions to the Decade.
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