Structural and stratigraphic evolution of late Cretaceous convergent margins of southern Alaska and California

Conference · Mon Feb 01 04:00:00 EST 1988 · AAPG Bull.; (United States)

OSTI ID:5791765

Nilsen, T H

The most prominent and well-preserved remnants of the convergent margins are present in southern Alaska and California. The southern Alaska convergent margin appears to have developed in response to northward-directed subduction of the Kula plate and the California margin in response to eastward-directed subduction of the Farallon plate. The chief elements of the southern Alaska convergent margin, on the basis of paleomagnetic data, appear to have subsequently migrated northward and rotated in the post-Cretaceous. The chief elements of the California margin have been disrupted by Neogene strike-slip displacements on the San Andreas fault system and accretion of younger terranes to the west. In both southern Alaska and California, the forearc-basin deposits are well preserved and produce major amounts of gas. The principal reservoirs in Alaska are Tertiary nonmarine deposits and in California are Late Cretaceous and Tertiary deep marine and deltaic deposits. The accretionary wedge in southern Alaska forms a remarkably well-preserved assemblage of trench and trench-slope deposits that extend for about 2000 km along the Gulf of Alaska, flanked oceanward by younger accreted terranes. The accretionary wedge in California consists of a great variety of older and younger terranes, including some fragments of ocean crust that originated in southern latitudes. Comparative structural and stratigraphic analyses of the two Late Cretaceous margins reveals the complexity of tectonic, depositional, and stratigraphic patterns associated with subduction of very large oceanic plates at the margins of very large continental plates.

• Research Organization: Applied Earth Technology, Inc., Redwood City, CA (USA)
• OSTI ID: 5791765
• Report Number(s): CONF-880301-
• Conference Information: Journal Name: AAPG Bull.; (United States) Journal Volume: 72:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
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& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
ALASKA
CALIFORNIA
CRETACEOUS PERIOD
DEPOSITION
FEDERAL REGION IX
FEDERAL REGION X
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
MESOZOIC ERA
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
PETROLEUM DEPOSITS
RESOURCES
SEDIMENTARY BASINS
STRATIGRAPHY
TECTONICS
USA