The Venezuelan Foredeeps, Part II: Structure

Felipe Audemard and Jairo Lugo

A series of seismic reflection profiles document the evolutIon of the foredeeps where NNE-trending Jurassic half grabens were developed in a back-arc seffing on pre-existing Paleozoic folded-belts. These units were onlapped by a Cretaceous-Tertiary passive margin succession, which in turn was cannibalized by a complex folded-belt evolving from west to east. The northern Pedjd, a predominantly east-vergent basement-involved folded-belt, was first emplaced along the northwestern corner of Venezuela in Eocene times. Coeval to this event is the emplacement of most of the Lara nappes along north-central Venezuela, which override the passive margin for more than 200 km.

In Oligocene times, the western Serrania del Interior reached the vicinity of its present position in central Venezuela. During Late Oligocene- Middle Miocene most of the eastern Serrania del Interior was emplaced. At this time, the Perija Ranges were reactivated as part of the northern extension of the Eastern Cordillera of Colombia. During the Middle Miocene-Recent, the folded belts migrated eastward to the position of Trinidad to join the Barbados accretionary prism. To the west, the Venezuelan Andes evolved as a northwest-vergent basement-involved folded belt overriding the Maracaibo basin

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California