New structural data from central Hispaniola suggest that a mid-Cretaceous orogenic event resulted in the obduction of peridotites onto the early Antillean arc. The Maimón belt, which structurally underlies the peridotites, contains a shear zone composed of mylonitic and phyllonitic schists formed by northward thrust emplacement of the peridotites. Penetrative deformation decreases progressively to the northeast and is observed in the Neocomian sedimentary and volcanic rocks of the Los Ranchos Formation. The unconformably overlying, upper Albian–Cenomanian limestones are not penetratively deformed, thus bracketing the obduction to Aptian-Albian time. This event is synchronous with chemical changes of the arc magmas in Hispaniola, Puerto Rico, and central Cuba. Thus, they may both be related to the postulated Greater Antillean polarity reversal.