New Ideas About Displacement and History of El Pilar Fault, Eastern Venezuela

Abstract

El Pilar fault system has been subject to much controversy concerning its geodynamic significance and cinematic characteristics assigned it by various authors. One of the most widespread ideas is that this fault system is a segment of the boundary between Caribbean and South American plates, and exhibits a predominantly dextral displacement that could have attained 1000 km since beginning of the Tertiary. A dextral displacement is suggested of some 150 km during the last 15 ma at a rate of 1 cm/a, based on tectono-stratigraphic relationships across the fault system. If we admitted that El Pilar system constitutes the principal boundary between Caribbean and South American Plates, movement would have begun at beginning of Middle Miocene when the compressive phase began that was responsible for uplift and southeastward overthrusting of the Interior and Coastal Ranges.