Abstract: Tectonic Synthesis of Northwestern Venezuela and the Development of the Maracaibo Basin

J. R. Everett, R. J. Staskowski, S. P. Loyd, V. M. Tabbutt

Regional analyses of the stratigraphic and structural framework, and available geophysical and subsurface data integrated with an interpretation of mosaicked digitally processed Landsat I ages, provide insight into the complex plate interactions at the northern edge of the South American plate. Progressive eastward translation of the Caribbean plate along the northern edge of Venezuela and convergence at the western edge of South America throughout the Tertiary produced a series of complex movements on the Sierra de Perija, Venezuelan Andes (and the included Bocano fault) and Coa fault that bound the basin. These movements imparted successive known, others are relatively unexplored.

Plate tectonic considerations suggest that there are 1000+ km of post-Cretaceous right-lateral offset between the Caribbean and South American plates. However, there is no through-going set of features that unequivocally constitute the plate boundary between the South American and Caribbean plates, the seismicity of the region is not consistent with the activity normally associated with plate boundaries, and several large faults of northern South America imputed to have large lateral movement (e.g., Oca and Bocano) may have only a few tens of kilometers of lateral displacement based on offset of lithofacies and structural features. Episodic small amounts of convergence between the South American and Caribbean plates may have overrun and obscured the implied large transform offsets tha mark the plate boundary.

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