Eclogite, associated glaucophane- and garnet-bearing inclusions, serpentinite, micaceous schist and marble, an amphibolite-serpentinite-quartz dike complex, and blueschist define a 180-km-long blueschist belt along northern Hispaniola. In central Hispaniola 80 km south is a parallel greenschist belt. The two belts are separated by a major fault zone. Both belts are of Cretaceous age or older.
This occurrence of paired metamorphic belts in Hispaniola is apparently unique to the Greater Antilles. It probably reflects a more rapid convergence during subduction of the Caribbean and American plates in the Hispaniola area than in areas to the east or west. The subduction zone dipped southward beneath Hispaniola before and during the Cretaceous Period.
During middle and late Eocene time, tectonic activity in the area changed to vertical uplift and perhaps horizontal offset along the fault zone that separated the two metamorphic belts and along parallel faults to the north. Rapid uplift during this time led to tectonic emplacement and exposure of earlier Benioff zone fragments.