Cocos Ridge Collision as a Driver for Plate Boundary Deformation in the Western Caribbean
Abstract
The subduction and collision of bathymetric highs can result in geodynamic changes along convergent plate boundaries, including intense upper plate deformation, increases in mechanical coupling and seismicity, migration and or cessation of volcanism and formation of forearc terranes. But how extensive can the deformation associated with these features be and what are the implications for the long-term formation and evolution of plate boundary zones? Plate boundary evolution and upper plate deformation in southern Central America associated with Cocos Ridge collision is well studied and indicates, 1) migration of the volcanic arc toward the backarc northwest of and cessation of volcanism directly inboard the ridge, 2) uplift of the Cordillera de Talamanca inboard the ridge, 3) shortening across the forearc Fila Costena fold and thrust belt, and 4) outer forearc uplift above and flanking the ridge. Recent geodynamical modeling of Cocos Ridge collision, combined with the results of kinematic block models for the Central American margin, suggests the ridge drives northwest-directed forearc motion from central Costa Rica northwest to the Cocos - Caribbean (Central American forearc block) - North America triple junction, greatly increasing the spatial scale of deformation. Upperplate deformation of the Central American margin to the southeast of the Cocos Ridge in Panama was not investigated in these models. We investigate the dynamics of Cocos Ridge collision along the entire Central American margin and the implications on plate boundary evolution with a new geodynamic model of ridge collision. Our model results are compared to a new GPS derived horizontal velocity field for Central America and preliminary results indicate that the Cocos Ridge drives the Panamanian isthmus into northern South America (i.e., the North Andes block).
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.T51A2307L
- Keywords:
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- 1209 GEODESY AND GRAVITY / Tectonic deformation;
- 8122 TECTONOPHYSICS / Dynamics: gravity and tectonics;
- 8158 TECTONOPHYSICS / Plate motions: present and recent;
- 8170 TECTONOPHYSICS / Subduction zone processes