Beyond the Motagua and Polochic faults: Active strike-slip faulting along the Western North America-Caribbean plate boundary zone
Abstract
I investigate the role of two strike-slip faults in the tectonics of the western North America-Caribbean plate margin. The Ixcan fault, located in Guatemala north of the Polochic fault, is seismically active, with earthquakes of magnitude up to 5.7 reported recently. Fault-plane solutions along this curvilinear but generally E-W trending fault indicate left-lateral, strike-slip displacement. Several historic earthquakes appear to have taken place along the Ixcan fault since 1728, the largest one being the 1816 event ( M = 7.5). The NW-SE trending Concordia fault in southeastern Mexico appears to be the site of the great ( M = 7.6) earthquake of 1902. Isoseismals for this event suggest shallow, left-lateral strike-slip faulting. I propose a seismotectonic model in which both faults are part of the deformation associated to the North America-Caribbean plate boundary zone. Transpressive structures are found in the fault steps between strike-slip fault systems.
- Publication:
-
Tectonophysics
- Pub Date:
- December 2010
- DOI:
- 10.1016/j.tecto.2010.10.002
- Bibcode:
- 2010Tectp.496...17G