The geologic sequence on Carriacou consists mainly of coarse volcaniclastics with subordinate limestone lenses, giving way upward to a widespread limestone unit, in turn overlain by fine-grained tuffaceous marine sediments. Sections were measured through these units and formal stratigraphic names proposed. The Anse la Roche Formation of coarse volcaniclastics, limestone, and subordinate silts contains a Pliolepidina tobleri foraminiferal fauna associated with late Eocene plankton. Early Oligocene rocks were not recorded. Late Oligocene to early Miocene volcaniclastics and limestones near Windward village contain a Miogypsina panamensis fauna and are succeeded by the mainly volcanic Belmont Formation, with the Kendace Calcareous Siltstone Member at the top. The overlying l mestones of the Carriacou Formation (late early Miocene) contain a Miogypsina staufferi/Operculinoides cojimarensis foraminiferal assemblage, and the early middle Miocene Grand Bay Formation contains O. cojimarensis in its lower part. The Carriacou molluscan assemblages, previously described as Miocene and Pliocene, are of early middle Miocene age.