--> Abstract: Structural Geology of the Inner Southern California Borderland: Styles and Patterns of Deformation, by H. G. Greene, M. P. Kennedy, and S. H. Clarke; #90992 (1993).

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GREENE, H. GARY, U.S. Geological Survey, Menlo Park, CA, MICHAEL P. KENNEDY, California Division of Mines and Geology, San Diego, CA, and SAMUEL H. CLARKE, U.S. Geological Survey, Menlo Park, CA

ABSTRACT: Structural Geology of the Inner Southern California Borderland: Styles and Patterns of Deformation

The inner Southern California continental borderland is defined as that stretch of continental margin lying in the offshore and coastal region of southern California between the San Clemente and Newport-Inglewood-Rose Canyon fault zones and extending from the Santa Cruz Island-Malibu Coast fault zone southward into Mexico. Examination of the recently published California Continental Margins Map Series of the region reveals new tectonic patterns. Here, predominant northwest-southeast-trending fault zones with north-south and east-west-oriented conjugate faults forms a distinct wrench-fault tectonic pattern. Major fault zones in this region include the San Clemente, San Diego Trough, Palos Verdes-Coronado Bank, and Newport-Inglewood-Rose Canyon. These fault zones along with cross-trend onjugate faults control the physiography and geology of the region.

Many of these fault zones are seismically active and exhibit evidence of recent movement. Classical, wrench-tectonic structures are associated with most of the fault zones, mainly in the form of oblique transcurrent movement, although evidence of more compressional stress is seen. This indicates that the region is subjected to complex Neogene and later tectonic forces.

Active tectonic movement along the Palos Verdes-Coronado and Newport-Inglewood-Rose Canyon fault zones appears to have stimulated submarine landslides and to have progressively offset submarine canyons. In addition, gravity and geologic data suggest that Tertiary movement along the San Clemente fault zone has offset Emery Knoll some 90 km right laterally, suggesting a minimum rate of motion of 9 km/m.y., assuming the fault zone may still be active.

AAPG Search and Discovery Article #90992©1993 AAPG Pacific Section Meeting, Long Beach, California, May 5-7, 1993.