329 Neogene paleontolgy in the northern Dominican Republic 7

One hundred and forty-five species are reported from the Cercado, Gurabo and Mao formations of the Rio Gurabo, and Rio Cana sections on the south flank of the Cibao Valley, northern Dominican Republic. Twenty-one species are new. The uppermost Cercado Formation and the Gurabo and Mao formations belong to the Radimella confragosa Zone (upper Miocene-Pliocene). Below the Cercado Formation the lower part of this zone coincides with the upper part of the brackish-water Cyprideis pascagoulaensis Zone (middle to upper Miocene). The two sections show increasing depth of deposition with decreasing age, the Rio Cana section remaining considerably shallower than the Rio Gurabo section. Beds, equivalent to the Gurabo Formation in the Rio Yaque del Norte section near Santiago, were deposited at greater depth than those of the Rio Mao, Rio Gurabo and Rio Cana sections farther west. Underlying beds in the Rio Yaque section (Arroyo Lopez) carry a fauna similar to that of the upper Cercado Formation. The lower part of the Rio Yaque section (Lopez and Baitoa) has a fauna that is similar to that of the amber sites on the south flank of the Cordillera Central and to that of the Anguilla Formation of the Lesser Antilles, which are believed to be of similar age (close to the early-middle Miocene boundary). 

Year published: 1988