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. Anisotropic properties in the NE of the Caribbean-South American plate are investigated based on the analysis of shear-wave splitting from new S local phase data. At the collisional front in the Caribbean and the South American plates and within the retro-arc region, fast wave polarization from local S phases show considerable variability. δt are small (<0.14 s) and no dependence with depth is observed suggesting the presence of an heterogeneous anisotropic region confined to the crust and that most of the upper-mantle wedge is isotropic. In the fore-arc, φ is fairly constant, the average value is sub-parallel to the Lesser Antilles trench and differs from teleseismic result, which is perpendicular to the trench, which suggests that the crust and mantle are decoupled. The difference between the δt found in S local events and teleseismic, suggests that there is another source of deep anisotropy, which can be attributed to mantle flow underneath or around the edges of the subducting Atlantic plate beneath the Caribbean. A mix combination of deformation mechanism such as micro-fractures EDA and vertical foliation on metamorphic rocks could be responsible for the large variability found for δt in S local phases in this region. Keywords: seismic anisotropy, deformation mechanisms, shear-wave splitting, crust, mantle RESUMEN . Se investigan las caracteristicas anisotropicas en el NE de la placa Caribe-Sur America basados en el analisis de nuevos resultados del desdoblamiento de ondas de corte en fases locales S. En el frente de colision entre placa Caribe y Suramerica y en la zona de retro-arco, la polarizacion de onda rapida en eventos locales S muestran considerable variabilidad. Los δt son pequenos (<0,14s) y no presenta dependencia con la profundidad, sugiriendo la presencia de una region anisotropicamente heterogenea confinada a la corteza, siendo ademas la cuna del manto superior isotropico. En el ante-arco, φ es poco variable, el valor promedio es sub-paralello a la trinchera de las Antillas Menores y difiere del valor obtenido para fases telesismicas el cual es perpendicular a la trinchera, lo cual sugiere que la corteza y el manto en esta zona se encuentran desacoplados. La diferencia entre los δt en eventos locales S y telesismicos, sugiere que existe otra fuente de anisotropia profunda, que se puede atribuir a flujo mantelico debajo o alrededor de los bordes de la placa Atlantica en subduccion debajo del Caribe. Una combinacion de mecanismos de deformacion, tales como micro-fracturas EDA y foliacion vertical en rocas metamorficas podria ser responsable de la gran variabilidad encontrada en los δt en fases S locales en esta region. Palabras claves: anisotropia sismica, mecanismos de deformacion, doblamiento de ondas de corte, corteza, manto.

CRUSTAL SEISMIC ANISOTROPY AT THE EDGE OF THE SOUTH-EAST BORDER OF CARIBBEAN AND SOUTH AMERICAN PLATES