123 



topical investigations will contribute significantly to knowledge of the geologic 

 history of the shelf. The investigations on these target areas include : 



Current 



Intermediate scale geologic mapping off southern New England, in the Gulf of 

 Maine (petroleum, and sand and gravel) and off the Carolinas (phosphate, pe- 

 troleum, sand). Sedimenation and provenance studies in selected estuaries and 

 coastal zone. 



Plawned 



Detailed geophysical studies on Georges Bank, an area of high petroleum 

 potential. 



Test drilling on the Blake Plateau to determine the three-dimensional distri- 

 bution and geochemistry (grade) of manganese and phosphate nodules. 



Research drilling to compare rock sequences in the northern and central part 

 of the shelf with those penetrated in JOIDES holes off Florida. 



Reconnaissance geophysical surveys and sampling to determine thickness, na- 

 ture, and oil and gas potential of continental rise sediments and the geologic 

 boundary between the continental margin and the deep ocean basin. 



GXJLF OF MEXICO-CAEIBBEAN ABEA 



Regional geologic analyses of the Gulf will be synthesized to provide informa- 

 tion required to manage the resources of this region, potentially one of the 

 worM's richest storehouse of oil, gas, and sulfur. Both detailed and reconnais- 

 sance studies will be continued in the Caribbean area. Included are : 



Current 



Analysis of seafloor sediments to determine distribution of heavy metals de- 

 posits and relation of seafloor sediments to living resources. 



Geoehemical invesitigation of organic materials in estuarine sediments to find 

 the effect of these materials on mineral concentration and to study the interplay 

 between sediments and industrial pollutants. 



Detailed geologic mapping in selected coastal areas, such as Padre Island Na- 

 tional Seashore, to understand the dynamics of sediment movement, and. in par- 

 ticular the destructive changes wrought by hurricanes. 



Planned, 



A regional geologic and structural map of the entire Gulf of Mexico to be pre- 

 pared at reconnaissance scale from data acquired on cooperative programs with 

 the Navy Oceanographic Office. 



Acceleration of the existing cooperative geologic mapping program with the 

 Commonwealth of Puerto Rico to decipher the structural framework and eval- 

 uate the petroleum and mineral potential of the Puerto Rico Shelf. 



Extension of regional geologic and geophysical studies of the Gulf into the 

 Caribbean Sea through a cooperative program with Navy Oceanographic Office. 

 This program will be a U. S. contribution to the International Caribbean Year, 

 and the International Decade of Ocean Exploration. 



PACIFIC CONTINENTAL MARGIN 



Major oil fields are contained, in the nearshore shelf off California and marine 

 heavy metal placers occur off the coast of northern California and southern Ore- 

 gon. The seaward extent of these petroleum and placer deposits cannot now be 

 evaluated due to lack of i-egional geologic analyses. Both reconnaissance and de- 

 tailed investigations are required in this region to assess the geologic hazards 

 in this earthquake-prone belt. Pacific continental margin studies include : 

 Current 



Compilation of land-sea geologic transects at an intermediate scale for the 

 inner shelf off northern California and southern Oregon to delineate heavy metal 

 placers and areas of high petroleum potential. Relation of these data to onland 

 mineral deposits and geology in order to enhance the overall resource appraisal. 



Large-scale geologic mapping, coupled with direct seafloor studies and core 

 drilling, in areas of high potential for thick placer and lode deposits of heavy 

 metals off the southern Oregon coast. 



Geologic mapping on the central California shelf at an intermediate scale to 

 locate potential earthquake-generating faults and to determine their history of 



