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E. W. Scott

Publications and source records attributed to E. W. Scott.

15 recordsLinked to original sources
USGS1980

A summary report of the regional geology, petroleum potential, environmental geology, and operational considerations in the area of proposed lease sale No. 68, offshore southern California

This report reviews geological, geophysical and technological data that are pertinent to proposed OCS Lease Sale 68. Under consideration are 26,000 mi 2 (67,400 km 2 ) of the California Continental Borderland north of the U.S.-Mexico boundary. The area includes both leased and unleased tracts and lies adjacent to the highly productive coastal basins of southern California. Factors that have contributed to petroleum generation in the onshore basins, such as thickness, burial depth and hydrocarbon content, are less favorable in parts of the offshore region. Nevertheless, regional geologic and geophysical mapping together with data from stratigraphic test wells and bottom samples suggest that source beds, reservoir rocks and traps are present beneath the borderland. Strata of Miocene age are widespread within the area of proposed OCS Lease Sale 68 and contain fair to excellent potential source rocks. Eocene and early Miocene sandstone beds in the Cortes Bank test well and late Miocene and Pliocene rocks in the Point Conception test well have porosities that are within the range of good reservoir rocks. Late middle Miocene through Pliocene sandy turbidites of reservoir quality possibly occur in some outer borderland basins. Additional prospective targets are fractured Miocene shale beds that may be present in the deeper basins and on the down-flank margins of major uplifts. Numerous structural and stratigraphic traps, which formed in response to late Cenozoic wrench tectonics, are distributed throughout the borderland.

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USGS1979

Resource report for proposed OCS lease sale no. 70, St. George Basin, shelf area, Alaska

St. George basin is a long (300 km), narrow (30-50 km) graben whose long axis strikes northwestward, parallel to the continental margin of the southern Bering Sea. Located near the Pribilof Islands, and beneath the virtually featureless Bering Sea shelf, the basin is filled with more than 10 km of sedimentary deposits. These sedimentary rocks are ruptured by normal faults associated with the sides of the graben; these ruptures commonly correlate with offsets in the basement surface. Offset along these faults increases with depth implying that they are growth-type structures. Basement rocks, that floor and flank St. George basin are part of an assemblage of Mesozoic eugeosynclinal rocks that extends from southern Alaska to eastern Siberia beneath the Bering Sea margin and outer shelf. A parallel belt of igneous rocks of late Mesozoic and earliest Tertiary age may also extend from western Alaska to northeastern Siberia beneath the inner Bering Sea shelf. The Bering Sea margin and adjacent shelf were apparently uplifted by the end of Mesozoic time, resulting in deep subaerial erosion• Following uplift, the outer Bering Sea shelf has undergone extensional rifting and regional subsidence. Differential subsidence has resulted in the formation of a series of basement ridges and basins whose axes parallel the Bering Sea margin. Some of these basins are very large to gigantic in size, e.g., St. George basin, and involve crustal subsidence exceeding 10 km. Such large scale crustal collapse suggests deep crustal or upper mantle processes, such as thermal metamorphism or stress-induced crustal migration. Nine wells drilled along the northern coast of the Alaska Peninsula, as well as several onshore Soviet wells in northeastern Siberia, relate directly to the submerged basins of the Bering Sea shelf. Although all of the wells on the Alaska Peninsula were abandoned as dry holes, shows of oil and gas were found. In addition, Soviet drilling resulted in the discovery of oil and gas shows in Oligocene and Miocene sandstone. Regional geologic and geophysical mapping suggests that there are suitable source beds, reservoir rocks, and traps within St. George basin. However, it is not known if hydrocarbons are present or if the possible reservoirs are of commercial size. A resource appraisal of St. George basin out to 200 meters water depth indicates that, at 5 percent probability, 6.4 billion barrels of oil and 18.6 trillion cubic feet of gas may be in the basin; at 95 percent probability 0.8 billion barrels of oil and 4.5 trillion cubic feet of gas may be in the basin. The statistical mean of the appraisal is 2.7 billion barrels of oil and 10.3 trillion cubic feet of gas. A large number of faults, evidence for recent movement along some of the faults, and high seismicity all indicate that faulting is a major environmental concern for the outer continental shelf region of the southern Bering Sea, especially in St. George basin. Most of the faults are potentially active and their movement is probably influenced by the local geology, including basement structures and sediment loading. Unstable sediment masses pose potential threats to resource development in the vicinity of the Pribilof Canyon. Volcanic activity along the Aleutian arc south of St. George basin may also pose an environmental hazard to petroleum development in the area. Another environmental hazard is the presence of shallow gas pockets, which could pose such problems during drilling as blowouts and liquefaction of bottom sediment.

Alaska↗
USGS1979

Resource report for proposed OCS lease sale 57: Norton Basin, Alaska

This report is a summary of information about an area of the northern Bering Sea continental shelf that is bounded by the Seward Peninsula on the north, by the line of the United States-Russia Convention of 1867 on the west, and by St. Lawrence Island and the coastline that rims Norton Sound on the south and east. Scholl and Hopkins (1969) report that a sedimentary basin underlies the offshore area. More recent data, which form the basis of part of this report, show the basin is deepest beneath Norton Sound; also, the basin has sufficient depth and areal extent that the basin may be a target for development of hydrocarbon resources after Outer Continental Shelf (OCS) Lease Sale 57. The informal, but widely used, name for the basin is Norton Basin. The following discussion includes regional geology, geologic history, and offshore structure and stratigraphy as background data to discussion of the hydrocarbon potential and resource appraisal of the offshore area. Sections on environmental geology and on the technology and manpower needed and available for development of offshore resources are also included.

Alaska↗
USGS1979

Resource report for the deep-water areas of proposed OCS lease sale No. 70, St. George Basin, Alaska

This report summarizes geological and geophysical data from the deep-water (greater than 200m) region of the St. George Basin lease sale area #70. The shallow-water region is discussed in detail by Marlow and others (1979a) in a companion report. The triangular deep-water region lies at the junction of the Bering shelf and the Aleutian Ridge (Fig. 2). This region is bounded on the northeast by the 200 m bathymetric contour that defines the edge of the Bering shelf, on the southeast by a meandering line that lies 3 miles north of the Aleutian Islands, and on the west by the 171°W longitude meridian. Hereafter, this triangular region is referred to as the Umnak Plateau region. The name is derived from a major bathymetric feature, Umnak Plateau, that covers most of the region.

Alaska↗
USGS1976

Summary report of the sediments, structural framework, petroleum potential, environmental conditions, and operational considerations of the United States Beaufort Sea, Alaska area

Proposed OCS Oil and Gas Lease Sale i54comprising approximately 20,000 sq km in the Beaufort Sea of northern Alaska, has good potential for petroleum in each of the three geologic provinces it contains. However, only about half of the proposed area underlies waters shallower than 20 m, the apparent present technologic limit for petroleum development in polar seas impacted by a drifting permanent ice pack.

Alaska↗