Petroleum prospects of the extensive Aleutian-Bering Sea region include: (1) thick sections (basins) of Cenozoic and, in some areas, Cretaceous strata underlying broad areas of the Bering shelf; (2) deformed Mesozoic rocks unconformably underlying these basins; (3) domal and diapiric structures associated with the more deeply submerged (water depth of 2,000 m) Umnak plateau area; (4) thick masses of Neogene beds in summit basins along the crestal region of the Aleutian Ridge; and (5), in very deep water (4,000 m), thick wedges of slightly to moderately deformed beds flanking its northern and southern sides.

The most promising prospects are the thick (2-6 km) accumulations of early Tertiary through Holocene beds that underlie the shallow submerged floor of the Bering shelf. For example, Norton, Anadyr, and Bristol basins are large inner-shelf basins of little-deformed coastal plain and neritic beds that underlie the shelf's major bays and gulfs. Pribilof, St. George, Zhemchug, Navarin, and other associated but unnamed basins, are elongate outer-shelf basins of broadly deformed and faulted marine deposits. These basins parallel the northwest trend of the adjacent continental slope; several of them are more than 200 km long. Whereas the inner-shelf basins are large structural sags, many of the outer-shelf basins appear to be fault-controlled grabens or half-grabens. Some of the shelf basins (e.g., Anadyr and probably Navarin) may include a basal sequence of Late Cretaceous strata. However, many of the outer-shelf basins are underlain by folded Cretaceous and Jurassic(?) beds, stratigraphic units that are not only prospects in themselves but may have supplied hydrocarbons to overlying Cenozoic structures.

Other promising prospects are the fairly large (as much as 30 × 80 km) summit basins of the 2,200-km-long Aleutian Ridge. Roughly rectangular in shape, these structures are physiographic as well as geologic basins. The floors of two of them, neighboring Amukta (171.7°W) and Amlia (173°W) basins, are overlain by about 1,000 m of water; they are underlain by a 3-4-km-thick section of sedimentary beds, chiefly of late Miocene and younger age. These basins, elongate parallel with the ridge, are bordered by major normal faults. The infilling section is broadly folded and disrupted along high-angle growth faults.

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