Dixon, Timothy and Farina, Fred and DeMets, Charles and Suarez-Vidal, Francisco and Fletcher, John and Marquez-Azua, Bertha and Miller, Meghan and Sanchez, Osvaldo and Umhoefer, Paul (2000) New kinematic models for Pacific-North America motion from 3 ma to present, II: Evidence for a "Baja California shear zone". Geophysical Research Letters, 27 (23). pp. 3961-3964. ISSN 1944-8007
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Abstract
We use new models for present-day Pacific-North America motion to evaluate the tectonics of offshore regions west of the Californias. Vandenburg in coastal Alta California moves at the Pacific plate velocity within uncertainties (~1 mm/yr) after correcting for strain accumulation on the San Andreas and San Gregorio-Hosgri faults with a model that includes a viscoelastic lower crust. Modeled and measured velocities at coastal sites in Baja California south of the Agua Blanca fault, a region that most previous models consider Pacific plate, differ by 3-8 mm/yr, with coastal sites moving slower that the Pacific plate. We interpret these discrepancies in terms of strain accumulation on known on-shore faults, combined with right lateral slip at a rate of 3-4 mm/yr on additional faults offshore peninsular Baja California in the Pacific. Offshore seismicity, offset Quaternary features along the west coast of Baja California, and a discrepancy between the magnetically determined spreading rate in the Gulf Rise and the total plate rate from a geological model provide independent evidence for a "Baja California shear zone.".
| Item Type: | Article |
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| Publisher’s Statement: | ©2000. American Geophysical Union. |
| ID number or DOI: | 10.1029/2000GL008529 |
| Keywords: | block; deformation; fault; gps; Mexico; plate; Southern California |
| Subjects: | Q Science > QE Geology |
| NAU Depositing Author Academic Status: | Faculty/Staff |
| Department/Unit: | College of Engineering, Forestry, and Natural Science > School of Earth Sciences and Environmental Sustainability |
| Date Deposited: | 12 Oct 2015 23:13 |
| URI: | http://openknowledge.nau.edu/id/eprint/730 |
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