Thick marine sedimentary and volcanic sequences accumulated in northern Venezuela and Trinidad during ?Late Jurassic and Cretaceous time. By latest Cretaceous time, the northern part of this sequence had been regionally metamorphosed and rapidly uplifted. Flysch troughs developed to the south which received exotic masses and turbidite sands until early Eocene time. These events are interpreted as resulting from southward movement of the Caribbean crust and its subduction into a south-dipping Benioff zone located north of Venezuela. This postulated Benioff zone is believed to have become inactive in latest Cretaceous time, and the resulting isostatic rebound apparently caused overthrusting which initiated the flysch troughs.

Mid-Eocene orogeny caused major changes in basin geometry and initiated crustal shortening, overthrusting, uplift, and strike-slip faulting in Venezuela and Trinidad. These events are believed to be related to east-west right-lateral transcurrent movement between the Caribbean and Americas Plate, which appears to have begun in Eocene time. Initially, the Caribbean Plate was offset a minimum of 35 km along faults which extended into western Venezuela and Colombia, but later the Andes also became involved in the relative movements between the plates.