2.1. From intra-oceanic subduction to arc-continent collision in the northern Caribbean plate
Located on the northern margin of the Caribbean plate, the geology of Hispaniola (Fig. 1) is the result of the SW-directed Cretaceous subduction to final oblique collision in the lower Eocene of the Caribbean intra-oceanic arc with the southern continental margin of North American (Draper et al., 1994; Pérez-Estaún et al., 2007; Escuder-Viruete et al., 2011a, 2011b, 2013a, 2013b). Occurrence of high-P mélanges and ophiolites in northern Hispaniola indicates that an intermediate proto-Caribbean oceanic basin was subducted at least since the Lower Cretaceous (Draper & Nagle, 1991; Krebs et al., 2011; Escuder-Viruete et al., 2011c; Escuder-Viruete & Pérez-Estaún, 2013). Volcanic and shallow plutonic rocks whose ages range from the Aptian to the lower Eocene record the magmatic activity in the Caribbean upper plate (Kesler et al., 2005; Escuder-Viruete et al., 2006, 2014; Torró et al., 2017, 2018). A cover of middle to upper Eocene to Holocene sedimentary rocks regionally overlies the arc-related rocks. This cover post-dates the magmatic island arc activity and records the oblique arc-continent collision in northern Hispaniola, as well as intra- and back-arc deformation in the central and southern areas of the island (Pérez-Estaún et al., 2007).
In northern Hispaniola (Fig. 1), the pre-collisional geologic history is recorded in the pre-Eocene igneous and metamorphic basement, which crops out in several inliers, termed El Cacheal, Palma Picada, Pedro García, Puerto Plata, Río San Juan y Samaná complexes (Draper & Nagle, 1991). These complexes make up the Caribbean subduction-accretionary prism (Escuder-Viruete et al., 2011a, 2013a, 2013b), including from lower to upper structural levels: metasediments of the subducted continental margin of North America (Samaná complex); ophiolitic fragments of the proto-Caribbean Ocean (northern Río San Juan complex); serpentinitic-matrix mélanges enclosing high-P blocks of the subduction channel (Jagua Clara mélange); and volcano-plutonic rocks of the Caribbean island arc and fore-arc (southern Río San Juan, Pedro García, Palma Picada, Puerto Plata and El Cacheal complexes). The eastward and structurally downward younging age of the main deformation in each structural unit reflects their progressive accretion to the Caribbean subduction-accretionary prism from the latest Cretaceous to the lower Miocene (Escuder-Viruete et al., 2011b; 2013b). During the middle Miocene, the tectonic regime changes from oblique arc-continent collision to crustal-scale strike-slip faulting and eastward escape of the Caribbean plate toward a collision-free side in the Atlantic Ocean (Draper et al., 1994). Still active in northern Hispaniola, this tectonic regime gave rise to transpressive tectonics, tectonic disruption, and lateral escape of blocks of the Caribbean subduction-accretionary prism (Escuder-Viruete & Pérez, 2020).