The four major Cenozoic tectonic phases in the Sierra de Perijá and adjacent basins are the early Eocene tectonic phase, the middle Eocene Caribbean orogeny, the late Oligocene phase, and the late Miocene to present Andean orogeny. Ages of unconformities associated with particularly rapid regional uplift during these phases are early Eocene (53 m.y.), middle Eocene (45 m.y.), late Oligocene (25 m.y.), and Pliocene (3 m.y.). Northwest-southeast compression may have commenced in the Perijá and the Maracaibo Basin as early as the early Eocene. By the middle Eocene the Macoa-Totumo arch had begun to form during intense alpine-type folding and...