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Abstract: Paleogene Turbidite System in the Maracaibo Basin: A New Exploration Frontier

E. Zambrano, L. Melendiez, S. Ghosh

Regional sequence stratigraphic analysis revealed the presence of Paleocene(?)-Lower Eocene lowstand turbiditic deposits in Maracaibo Basin. The emplacements of the Lara nappes on the north during late Paleocene triggered the development of a foredeep in the northeastern part of the Maracaibo Basin. During the ensuing lowstand stage, siliciclastic sediments poured into the foredeep principally from the southwest, and secondarily from the Merida and Banbacoas highs; olistoliths and argillaceous sediments could have come from the north. These sediments were deposited as lowstand prograding wedge (slopefan complex) and submarine fan lobes in a belt trending northwest-southeast beyond the eastern shore of the present day Lake Maracaibo. The slope-fan complex consists of stacked progradati nal clinoforms with toesets of shingled turbidites. The exploratory potential of the slope-fan complex is still under study. Basinward the slope-fan facies grades into a thick, mappable and convex submarine fan lobe (Basin Floor Fan) overlying Paleocene strata. Farther eastward of this subsurface turbidite complex, extensive outcrops of coeval turbidites of the Trujillo-Rancheria formations occur in the Serrania de Trujillo.

The subsurface shelf-fed turbidite complex, as yet untested, may be of considerable economic interest as the potential fan lobe trap overlies the rich La Luna Eocene kitchen. Oil generation was relatively early (Middle Eocene) in this part of the basin. Early hydrocarbon generation and migration along vertical/subvertical faults would have filled the trap and preserved the porosity from destructive diagenesis. If hydrocarbons are present, this area may well become the new exploration frontier of the Maracaibo Basin.

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