Recent Evolution of the Northern Caribbean Plate Boundary Insights from Seismic Reflection Data from the Northern Hispaniola Margin

The northern margin of Hispaniola is characterised by a complex morpho-structure shaped by the interplay of geodynamic, tectonic, and sedimentary processes. The Haiti Seismic Investigation (HAITISIS) of the northern Caribbean plate boundary reveals evidence of oblique convergence. It elucidates the relationships among fault-driven tectonic activity, seafloor morphology, and the effects of transpressional deformation. The markedly different morpho-structural characteristics of the seafloor and sedimentation patterns in the Eastern and Western domains of the northern Hispaniola margin originated during the Upper Miocene-Pliocene tectonic reorganisation of the northern Caribbean Plate boundary. This regional reorganisation is associated with the onset of the oblique collision between the Caribbean and North American Plates that carried Hispaniola to the transpressive plate boundary opposite the Bahamas Carbonate Platform. This tectonic process led to the formation of an accretionary prism and activated segments of the eastern strand of the Septentrional-Oriente Fault Zone (SOFZ), resulting in lateral sediment source displacements and influencing sedimentary infill and deformation patterns. A mass transport deposit (MTD) in the Eastern domain is thought to have formed during this period of tectonic instability. Differential compaction and remobilisation of recent seismic units caused by the MTD have influenced the seafloor morphology of the Eastern domain. The MTD is absent in the Western domain, as are the canyons found in the Eastern domain. Our interpretation of the early Miocene initiation of the SOFZ and its evolution differs from previous studies that assume continuous eastward propagation. Morphologic features, such as the lateral displacement of canyons, provide a chronology for the development of strike-slip and thrust faults prior to the initiation of the SOFZ.