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).