URBINA C., CORNELIO A., Corpoven, S.A., Caracas, Venezuela

ABSTRACT: Structural Style on Southern Flank of Merida Andes, Venezuela

The Merida Andes exhibit the most complex tectonics in western Venezuela. By studying the different ages and regional distribution of rocks, we can describe some tectonic features which are of interest to oil exploration in this area.

Vertical basement movements accompanied extensional tectonics from pre-Cambrian until Eocene times. For this time interval, we reconstructed diverse normal fault systems and associated subsidence. From Eocene time onwards, compressional tectonics gave origin to anticlines and reverse, thrust and back-thrust faults. Neo-tectonic movements have modified existing structures by dislocation along transcurrent fault systems.

GeochemicaI analyses have determined the presence of hydrocarbon source rocks equivalent to the a Luna Formation of the Maracaibo Basin; seismic, surface and subsurface data prove the existence of excellent seals in the Eocene Paguey Shale.

The principal problem is to determine the timing of hydrocarbon migration with respect to the timing of trap formation.

It is highly probable that the sapropelic strata of the Navay Formation, equivalent to the La Luna Formation, is presently expelling hydrocarbons to traps in the Barinas Basin, under presently existing temperature-pressure conditions.

AAPG Search and Discovery Article #90988©1993 AAPG/SVG International Congress and Exhibition, Caracas, Venezuela, March 14-17, 1993.