Morphology, structure, and kinematics of the San Clemente and Catalina faults based on high-resolution marine geophysical data, southern California Inner Continental Borderland

Geosphere
By: , and 

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  • More information: Publisher Index Page (via DOI)
  • Data Releases:
    • USGS data release Minisparker and chirp seismic-reflection data of field activity 2014-645-FA collected in the outer Santa Barbara Channel, California, 2014-11-12 to 2014-11-25 (
    • USGS data release Multichannel minisparker and chirp seismic reflection data of U.S. Geological Survey field activity 2016-616-FA collected in the Catalina Basin offshore southern California in February 2016
    • USGS data release Multibeam bathymetry and acoustic-backscatter data collected in 2016 in Catalina Basin, southern California and merged multibeam bathymetry datasets of the northern portion of the Southern California Continental Borderland
    • USGS data release Quaternary faults offshore of California
  • Open Access Version: Publisher Index Page
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Abstract

Catalina Basin, located within the southern California Inner Continental Borderland (ICB), is traversed by two active submerged fault systems that are part of the broader North America-Pacific plate boundary: the San Clemente fault (along with a prominent splay, the Kimki fault) and the Catalina fault. Previous studies have suggested that the San Clemente fault (SCF) may be accommodating up to half of the approximately 8 mm/yr right-lateral slip distributed across the ICB between San Clemente Island and the mainland coast, and that the Catalina fault (CF) acts as a significant restraining bend in the larger transform system. Here, we provide new high-resolution geophysical constraints on the seabed morphology, deformation history, and kinematics of the active faults in and on the margins of Catalina Basin. We significantly revise SCF mapping and describe a discrete releasing bend that corresponds with lows in gravity and magnetic anomalies, as well as a connection between the SCF and the Santa Cruz fault to the north. Subsurface seismic-reflection data show evidence for a vertical SCF with significant lateral offsets, while the CF exhibits lesser cumulative deformation with a vertical component indicated by folding adjacent to the CF. Geodetic data are consistent with SCF right-lateral slip rates as high as ~3.6 mm/yr and transpressional convergence of <1.5 mm/yr accommodated along the CF. The Quaternary strands of the SCF and CF consistently cut across Miocene and Pliocene structures, suggesting generation of basin and ridge morphology in a previous tectonic environment that has been overprinted by Quaternary transpression. Some inherited crustal fabrics, especially thinned crust and localized, relatively hard crustal blocks, appear to have had a strong influence on the geometry of the main trace of the SCF, whereas inherited faults and other structures (e.g., the Catalina Ridge) appear to have minimal influence on the geometry of active faults in the ICB.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Morphology, structure, and kinematics of the San Clemente and Catalina faults based on high-resolution marine geophysical data, southern California Inner Continental Borderland
Series title Geosphere
DOI 10.1130/GES02187.1
Volume 16
Year Published 2020
Language English
Publisher Geological Society of America
Contributing office(s) Pacific Coastal and Marine Science Center
Description Report: 24 p.; 4 Data Releases
Country United States
State California
Other Geospatial San Clemente fault, Catalina fault
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