Characteristics and alternative mechanisms of late Quaternary faulting, proposed LNG Terminal Site, Point Conception, California
Characteristics and alternative mechanisms of late Quaternary faulting, proposed LNG Terminal Site, Point Conception, California
Bulletin of the Association of Engineering Geologists (May 1985) 22 (2): 171-192
- active faults
- California
- Cenozoic
- detection
- displacements
- distribution
- earthquakes
- engineering geology
- faults
- models
- Neogene
- Pliocene
- Point Conception
- Quaternary
- Santa Barbara County California
- Sisquoc Formation
- structural geology
- Tertiary
- United States
- upper Quaternary
- Arroyo Fault
- Little Cojo Bay LNG Terminal Site
Late Quaternary faults at the proposed Point Conception LNG site consist of westerly-trending reverse faults that are parallel to bedding in the Pliocene bedrock beneath the terrace deposits, and southwesterly-trending cross-faults that offset displacements along the bedding-plane faults. Flexural slip and backthrust models have been proposed as mechanisms for site faults. While the faults exhibit some characteristics expected from the flexural slip model, data on shoreline-angle elevations on both flanks of the Government Point Syncline clearly prohibit flexure of this structure during the period of fault movements. A simple backthrust model does not expalin the spacing of site faults, but an antithetic model taken from ramp regions of overthrusts could explain this characteristic.--Modified journal abstract.