Options for Scientific Ocean Drilling (1982) / Chapter Skim
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The Case for Future Drilling
The Case for Future Drilling
Pages 3-9
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From page 3... ...
The willingness of other nations to participate in the scientific work and to help finance the operation is emphatic evidence of the high international regard in which the project has been held. The many accomplishments of DSDP have been well-documented, and we cite here only a few examples, such as verification of the sea-floor spreading model, demonstration of large-scale vertical movement and the discovery of past chemical, physical, and biological ocean environments different from those *
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From page 4... ...
But this reconnaissance section, valuable as it is, is built upon only about 500 drill sites in the deep oceans, or one data point for each 275,000 square miles. Further investigation of this section, its variations, and its relation to continental crust hold promise of major advances in understanding earth history, composition, structure, and resources.
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From page 5... ...
Sediments bear the imprint of ocean temperatures and currents, information critical to the reconstruction of oceanic circulation of the past, and hence to the reconstruction of ancient climates and ultimately to a better understanding of the nature of modern climate and of climatic change. Drilling provides access to the rocks of the oceanic crust, and thus is helping to unravel its structures and motions, information required to understand the phenomena of seafloor spreading and continental drift, and, more broadly, the structure of the earth as a planet.
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From page 6... ...
Indeed the results confirmed the concept of seafloor spreading, the relationship of crustal age to magnetic anomalies, the basaltic nature of the oceanic crustal rocks, and, through the systematic sampling afforded by the drill, initiated an entirely new field of study: paleoceanography. "This technology has taken geological sciences through more than a decade of unprecedented advancement and has been instrumental in bringing us to our present level of understanding of the origin and history of the ocean environment.
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From page 7... ...
The hydraulic piston corer, recently developed by DSDP engineers, allows the taking of overlapping five-meter undistorted cores of soft sediments, aggregating several hundred meters. These remarkable samples studied with new highly sensitive magnetometers can lead to a refined global magnetic stratigraphy.
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From page 8... ...
4. Passive margins Passive continental margins result from rifting, formation of spreading centers, and the generation and lateral movement of new crust.
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From page 9... ...
Atop the continental transition are thick wedges of sediment -- some half of all the marine sediments deposited during the past 200 million years. Because of these enormous wedges of sediments, the passive margins have the potential of containing gas and oil, a potential that precludes deep penetration without a full riser and blowout prevention system.
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