Four major Paleogene sedimentary belts—the Peralta, El Mamey, and Tavera Belts of Hispaniola, and the Cerrillos Belt of Puerto Rico—provide important constraints on the Eocene-Miocene tectonic evolution of the northern Caribbean. The southeastern half of the Peralta Belt consists of two basinal sequences, the lower to upper Eocene Peralta Group, and the middle(?) Eocene to lower Miocene Rio Ocoa Group, which were deposited along the southwest margin of the Greater Antilles island arc during, and after, the last stages of arc magmatism. Peralta Group strata are cut by thick, stratally disrupted thrust fault zones, and probably record development of an...