Abstract: Tectonic Analysis, Sequences and Sediment Sources in the Central Part of the Eastern Venezuela Basin (Anzoategui State Area)

P. Rodriguez, Luis Oswaldo

The post-Paleozoic tectonic origin of the Eastern Venezuela Basin can be summarized in three major phases: 1. Late Jurassic rifting, 2. Cretaceous-Paleogene passive margin, and 3. a diachronous Paleogene-Quaternary foreland development.

In the central part of the Eastern Venezuela Basin, tectonic analysis shows that the tectonism responsible for the development of the foreland, the Eastern Venezuela Basin, was an episodic process that started 28 Ma (uplifting of the Guarico Thrust) and it was followed by three main tectonic events that occurred at 22 Ma (beginning of the uplift of the Serrania del Interior), 14 Ma and 7 Ma. During this foreland basin phase (Lower-Mid Miocene to present) more than 8 km of sands and shales were accumulated.

A total of fourteen tectonic-generic sequences can be identified in the Miocene-Pliocene section. Those sequences were controlled by tectonic events associated with the oblique collision between the Caribbean and South America plates.

The central part of the Eastern Venezuela Basin was mainly fed by sources located (1) in the Guarico thrust, (2) in the Serrania del Interior, and (3) by rivers draining the Guayana shield. However, the main source for the lower Miocene Oficina formation was located far away from this area, in the Andes where deformation started in the mid Miocene-Pliocene.

AAPG Search and Discovery Article #90951©1996 AAPG International Conference and Exhibition, Caracas, Venezuela