with an appendix by

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 Eocene accretion-ary prism composed of offscraped trench deposits. Ocoa Group strata lack these strat-ally disrupted fault zones, and we interpret these rocks as fore-arc basin deposits. The Peralta underthrusting event was probably amagmatic and may have been related either to transpression associated with the earliest stages of the presently active left-lateral, strike-slip regime of the northern Caribbean; or to "back-arc " compression associated with the last stages of the arc-Bahamas collision along the northeast margin of the arc