Seismic structure of the crust in the western Dominican Republic

TL;DR

This study uses wide-angle seismic data to model the crustal and tectonic structure of the northeastern Caribbean Plate boundary, revealing complex subduction zones and mantle anomalies in the western Dominican Republic.

Contribution

It provides detailed 2D P wave velocity models of the region, highlighting the oblique subduction contact and mantle anomalies associated with fault zones and seismic activity.

Findings

Oblique subduction with Moho dipping 11° NNE SSW.

Deep-reaching mantle velocity anomalies linked to fault zones.

Possible detached oceanic slab explaining deep seismicity.

Abstract

The contact between the Caribbean and North American plates is a tectonically complicated boundary where the deformation is accommodated in north and south of Hispaniola by the Enriquillo Plantain Garden and Septentrional Oriente Fault Zones. We present a crustal and tectonic study of the Northeastern Caribbean Plate Boundary from wide-angle seismic data acquired during the GEOPRICO-DO and CARIBE NORTE surveys, showing two transects crossing, from north to south, North American Plate, Bahamas Platform, central Hispaniola and Caribbean Plate. The results presented include two 2D P wave velocity models of 425 km and 200 km long oriented NNE SSW and ENE SSW, respectively, obtained by the travel time forward and inverse modeling of the WAS data. Our study defines that the contact between Bahamas Platform, North American Plate and Hispaniola corresponds to oblique subduction with the Moho dipping 11 in the NNE SSW direction. Furthermore, in the south, our results reveal the existence of an anomalous deep-reaching zone of lateral velocity variation in the mantle that could be associated with EPGFZ and a possible detached oceanic slab from NOAM that could explain the deep seismicity in the region.