El límite Cretácico Inferior-Cretácico Superior en México basado en los foraminíferos planctónicos

Abstract

The Lower Cretaceous/Upper Cretaceous boundary in Mexico is established at the base of the Thalmanninella ticinensis/Thalmanninella evoluta Interval-Zone, corresponding to the Zone with Stoliczkaia dispar of the ammonite scheme of zonation. The Vraconian is regarded as a valid stage and represents the time comprised by the zone with Stoliczkaia dispar. In Mexico the lower Cretaceous/Upper Cretaccous boundary lies within the Cuesta del Cura Limestone.