Seabed Assessment Program 



This program funded basic research that focused on the 

 geological processes along continental margins, midocean ridges, 

 and deep-sea basins. In the last decade, Earth scientists began to 

 recognize the subtle relationship between the movements of the 

 Earth's crust and the active processes in the world's oceans and 

 their bearing on the origin and development of hydrocarbon and 

 metallic ore deposits. 



The projects supported by Seabed Assessment are broadly 

 grouped as Continental Margin Studies, Plate Tectonics and 

 Metallogenesis, and the Manganese Nodule Program. 



Continental Margin Studies 



The continental margin was studied to better understand the 

 rifting of continental land masses and the effects of the rifting on 

 the margins. Continental margins are broadly divided between 

 passive (pull-apart) and active (compressive) types. The margins 

 around the Atlantic are almost all passive; those around the 

 Pacific are active. At the beginning of the decade, knowledge of 

 the origin and structure of margins was poorly known and very 

 uneven. 



Continental Margin Data 



Continental Margin data received during the period of this 

 report are available from NGSDC as follows: 



NGSDC Accession No.: 10020005 

 Organization: University of Texas at Galveston 

 Investigator: J. Watkins (U. of Texas) 

 Grant No.: OCE 74-02923 

 Project: Continental Margin Studies 



Data: 2,500 bathymetric and 5,200 magnetic observations on 

 magnetic tape. 



Continental Margin Bibliography 



Cande, S. C, and P. D. Rabinowitz. 



1978. Mesozoic seafloor spreading bordering conjugate conti- 

 nental margins of Angola and Brazil. 10th Ann. Offsh. Tech. 

 Conf., Houston Tex. p. 1869-1876. 



Kumar, N. and L. A. P. Gamboa. 



1979. Evolution of the Sao Paulo Plateau (Southeastern 

 Brazilian Margin) and Implications for the Early History of the 

 South Atlantic. Geological Society of America Bulletin, Part I 

 90:281-293. 



Leyden, R., J. E. Damuth, L. K. Ongley, J. Kostecki, and W. 



Stevenick. 



1978. Salt diapirs on Sao Paulo Plateau, southeastern Brazilian 

 continental margin. Amer. Assoc. Petrol. Geologists Bui. 

 62:657-666. 



Rabinowitz, P. D. 



1976. Geophysical study of the continental margin of southern 

 Africa. Geol. Soc. Amer. Bui. 87:1643-1653. 



Plate Tectonics and Metallogenesis Studies 



A fuller understanding of the origin and development of ore 

 deposits is needed to guide the search for new reserves of minerals 

 vital to industrial civilization. One of the significant implications 

 of plate tectonic theory is that active processes along plate 

 margins relate in subtle ways to the formation both of economic 

 metal deposits and hydrocarbon accumulation. The subject is a 

 complex, multifaceted one that includes both sea floor- and 

 mountain-building processes. The circum-Pacific belt, character- 

 ized by active subduction zones, parallels to varying degrees some 

 of the world's major metallogenic provinces. At one end of the 

 system, hydrothermal processes along the spreading centers of the 

 ocean floor show evidence of metal concentrations, and at the 

 other end in the mountain belts, suites of rocks in the zones of 

 metal accumulation suggest deep marine origin. Following the 

 paths of the metals from the source to the mine is a major scientific 

 problem in Earth science that the Seabed Assessment Program 

 supported in part through several projects. 



Plate Tectonics and Metallogenesis Studies Data 



Plate Tectonics and Metallogenesis Studies data received 

 during the period of this report are available from NGSDC as 

 follows: 



NGSDC Accession No: 07080003 



Organization: Oregon State University 



Investigator: L. Kulm (OSU) 



Grant No: OCE 76-05903 



Project: Plate Tectonics 



Data: 3,800 n.mi. of bathymetric and seismic data on microfilm. 



NGSDC Accession No: 08015012 

 Organization: Hawaii Institute of Geophysics 

 Investigator: G. Woollard (HIG) 

 Grant No: GX-28674 

 Project: Plate Tectonics 



Data: Mineralogy, geochemistry, and geochronology of 18 core 

 samples in published data report. 



NGSDC Accession No: 08995007 

 Organization: Hawaii Institute of Geophysics 

 Investigator: G. Woollard (HIG) 

 Grant No: GS-28674 

 Project: Plate Tectonics 



Data: Geochemical analyses of 10 core samples in published data 

 report. 



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