Multichannel and single-channel seismic reflection profiles across the outer edge of the Bering Sea Shelf between Cape Navarin and the Aleutian Islands reveal thick sedimentary sections underlying the continental slope and rise. This segment of the Bering Sea margin, about 700 km long, is covered by 200 to 3,400 m of water and is incised by several large submarine canyons. The sedimentary section overlying acoustic basement ranges from 0 to 10 km in thickness, and the thickest parts (7 to 10 km) are located at the base of the slope along the northern and southern areas of the margin. A maximum thickness of 10 km (5.9 sec, two-way) occurs in uplifted rise deposits that lie in 800 m of water near the mouth of Zemchug Canyon.

Recent dredging along the continental slope indicates that upper Eocene or lower Oligocene sediment lies unconformably on an Upper Jurassic acoustic basement. The reflection profiles across the sediment-draped areas of the margin suggest that only the upper half of the thick sedimentary section at the base of the slope is younger than early Oligocene. The age of the deeper sediment may be as old as Mesozoic.

Several aspects of the sediment wedges along the Bering Sea margin make these wedges favorable targets for future hydrocarbon exploration: (1) the large total thickness of Cenozoic sediment; (2) the presence of internal structural and stratigraphic features such as diapirs, faults, crustal warps, onlaps, and pinchouts; and (3) the likelihood of Cenozoic source areas rich in organic and coarse-gained detrital debris.

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