collected during joint programs with the Navy and Puerto Rican Gk>vern- 

 ment and, during IDOE cruises, with the University of Mexico and par- 

 ticipants from other countries. Activities completed during 1971 included 

 preliminary compilations of the geology south of Puerto Rico and of geo- 

 physical data for 15,000 miles of traverse in the Gulf of Mexico; reports 

 on the geologic structure from south Texas to the Tabasco State of Mexico 

 and on a large gravity anomaly beneath the central Florida shelf ; and maps 

 showing the geology and structure of the eastern Greater Antillean region 

 and the geochemistry of bottom sediments on the northern shelf of the 

 gulf. 



Along the west coast, USGS studies and completed reports emphasize the 

 location of faults and o'ther structures beneath the ocean floor off California 

 and Oregon, the heavy metal potential of sands off northern California, and 

 the geochemical properties of sediments and sedimentation processes off 

 northern California and Oregon. Some results represent products of re- 

 search contracts with the Scripps Institution of Oceanography and the 

 University of Oregon. Off Alaska, geologic and geophysical mapping dur- 

 ing 1971 resulted in reports on the offshore petroleum potential of the 

 Pacific Margin Tertiary Basin along the southern coast of the State, on 

 structures of the Aleutian Bering Region, and the geology of the Chukchi 

 Sea. The Chukchi Sea studies were jointly conducted by the USGS and the 

 Coast Guard. 



The current search for sand is focused offshore with the intent to explore 

 and inventory deposits suitable for future beach-fill requirements and sub- 

 sequently to develop and refine techniques for transferring offshore sand 

 to the beach as a part of the Corps of Engineers' beach erosion control and 

 shoreline hurricane protection program. A new program will begin this 

 year in the Cape Fear area of North Carolina, and reports wall be prepared 

 for central and northern Florida, the New York Bight, Cape Cod Bay, and 

 the entrance to the Chesapeake Bay. In Fiscal Year 1973, data will be col- 

 lected off southern California between Santa Barbara and Los Angeles 

 and reports will be completed for Long Island Sound, the south shore of 

 Long Island, and Cape Fear. 



Leasing and Management of Mineral and Petroleum Resources 



Each major area of high petroleum and mineral potential that has been 

 identified or is now being developed presents conditions that are unique 

 or differ significantly from those of the other areas. Resource appraisal 

 programs are, therefore, adjusted to meet the specific requirements in each 

 area. Along the Gulf of Mexico and southern California coasts, offshore 

 oilfields are extensions of, or similar to, those of adjacent land areas; the 

 structures and nature of the geologic formations in which oil may be found 

 can be predicted, most drilling conditions are known, and processing facili- 

 ties are generally nearby. Along other coasts, however, the geological relations 

 between onshore and offshore areas are less well known. Consequently, much 

 greater effort is needed to evaluate the many factors that must be considered 

 before lease sales permitting exploratory drilling are made. 



41 



