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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 64 (1980)

Issue: 5. (May)

First Page: 745

Last Page: 745

Title: Hydrocarbon Prospects of Bering Sea Shelf South of St. Lawrence Island, Alaska: ABSTRACT

Author(s): M. S. Marlow, A. K. Cooper, D. W. Scholl

Article Type: Meeting abstract

Abstract:

Hydrocarbon prospects of the Bering Sea shelf are encouraging because of the presence of numerous, large sediment-filled basins, a variety of structural and stratigraphic traps, and potential reservoir beds. The large shelf area south of St. Lawrence Island is underlain by at least 13 sediment-filled basins. One of these basins, Bristol Bay basin, extends offshore from the Alaska Peninsula and contains more than 3 km of section. Nearby on the northwest is St. George basin, a graben approximately 300 km long and 50 km wide that includes a section about 10 km thick. The northwestern region of the shelf near Siberia is underlain by the large Navarin basin province (40,000 sq km), which comprises three subshelf basins that contain sections as much as 15 km thick.

Structural traps for hydrocarbons occur as folds associated with growth faults flanking the basins, strata draped over basement blocks, regional dip divergence in the upper sedimentary basin sequence, and thinning of beds against the basement flanks of the basins. Diapirlike folds as well as large anticlinal structures occur in the Navarin basin province.

Rocks dredged from the Beringian continental slope include volcanic sandstone of Late Jurassic age, mudstone of Late Cretaceous age, and less consolidated deposits of early Tertiary age. Pyrolytic analyses of these rocks indicate that none are good source beds for petroleum; however, the samples are generally sandy units that may not be representative of finer grained possible source beds that may be present along the margin or within the subshelf basins. Tertiary samples are generally porous--probably because of abundant diatom frustules. The permeability of these rocks is variable. Tertiary outcrops can be traced as seismic reflectors to the subshelf basins, where, if the beds remain diatomaceous, potential reservoir beds may be present.

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Copyright 1997 American Association of Petroleum Geologists