Eastern Venezuelan basin (EVB) is located in the northern South America, in the easternmost part of Venezuela, and it has been filling from the southwest by the Orinoco River since late Miocene – early Pliocene (?), forming the 12-km- thick Orinoco Delta in the Atlantic Ocean. To improve our understanding of the paleogeography and hydrocarbon potential of the eastern Venezuelan basin and the adjacent, thickly-buried segment of the South American passive margin, we use 620 km2 of 3D seismic, 650 km of 2D seismic, and five wells with well logs from the Punta Pescador area of northeastern Venezuela near the Columbus Channel and the border with Trinidad.

The following sequence of Cenozoic events affecting the passive margin are proposed: (1) during the Oligocene and early Miocene, south to north flowing fluvial systems and associated deltas progradated northward from the Guyana shield; (2) the late Miocene Messinian event lowered eustatic sea level along the passive margin and produced a major erosional event that breached a continental high which allowed the Orinoco Delta to prograde rapidly into the deeper water Atlantic area in the earliest Pliocene; and (3) early Pliocene to recent progradation of the Orinoco Delta is well documented into the deeper water areas of Trinidad and offshore Venezuela.

The onset of major input of the Orinoco River in this area is thought by most workers to be late Miocene in age, which is supported by a change in the flow direction interpreted in the seismic data, from south-north in the pre-late Miocene–early Pliocene section to southwest to northeast direction in the Pliocene to Recent sequence. Through the Cenozoic time, a superposition of fluvial system over deltaic and deep water facies evidences the progradation of the facies and the filling of the basin.