ANALYSIS OF SUBSIDENCE IN NORTHEASTERN VENEZUELA AS A DISCRIMINATOR OF TECTONIC MODELS FOR NORTHERN SOUTH-AMERICA

Subsidence analysis of northeastern Venezuela's exposed, parautochthon ous Lower Cretaceous-Miocene sedimentary section reveals an Atlantic-t ype passive-margin subsidence history for the entire Cretaceous-middle Eocene interval; Oligocene-Miocene subsidence was rapid and great and was caused by foredeep formation and emplacement of the fold-and-thru st belt that now exposes the passive-margin sedimentary section. Our a nalyses support tectonic models of South America's northern margin whi ch propose Cenozoic eastward migration of a foredeep along northern So uth America's late Mesozoic passive margin. The calculated subsidence is inconsistent with tectonic models that propose middle or Late Creta ceous subduction or obduction.