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Structural Evolution of Wilmington, California, Anticline

John N. Truex
Structural Evolution of Wilmington, California, Anticline
AAPG Bulletin (1974) 58 (12): 2398-2410


The structural evolution of the Wilmington anticline in the Los Angeles basin, California, began with middle Miocene folding which probably was not coincident with the present anticlinal axis. The ancestral fold was truncated prior to the start of late Miocene deposition. Uninterrupted sedimentation occurred throughout the late Miocene. No evidence of the present Wilmington anticline is seen prior to the deposition of the lower part of the Ranger zone. The source of sediment supply was in the northeast and the direction of transport, southwest. Growth of the Wilmington anticline was initiated in late Miocene, during deposition of the early Ranger zone. Most Ranger subzone isopachs reflect Ranger structure, and demonstrate continuous anticlinal growth during the early Repettian Stage of the Pliocene. Movement on the Long Beach Unit fault began during deposition of the Ranger X sand and culminated at the close of F sand deposition. The F sand was eroded and channeled by current action along and across the anticlinal axis prior to Fo sand deposition. The Fo sand was deposited as a lens-shaped body on the eroded F, and is present over a minimum 48-sq-mi (124.3 sq km) area. No evidence of structural growth during the deposition of this sand is present, in contrast to the other Ranger sands. The Fo is thought to be primarily a tractionite. Renewed uplift and additional movement on earlier faults occurred throughout the Repettian Stage. Uplift and truncation of the Repettian occurred prior to the deposition of the Pliocene Pico Formation. Southward tilting during the middle Pleistocene Pasadenan orogeny completed the Wilmington structural evolution.

ISSN: 0149-1423
EISSN: 1558-9153
Coden: AABUD2
Serial Title: AAPG Bulletin
Serial Volume: 58
Serial Issue: 12
Title: Structural Evolution of Wilmington, California, Anticline
Author(s): Truex, John N.
Pages: 2398-2410
Published: 1974
Text Language: English
Publisher: American Association of Petroleum Geologists, Tulsa, OK, United States
Accession Number: 1975-014654
Categories: Economic geology of energy sources
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. (incl. sketch maps)
N33°45'00" - N34°45'00", W118°49'60" - W117°40'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute.
Update Code: 1975
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