Las subdivisiones bioestratigráficas de la Biozona Bimammatum (Oxfordiense Superior) en la Cordillera Ibérica nororiental: facies y amplitud de las discontinuidades

Abstract

Middle to Upper Oxfordian rocks in the northeastern Iberian Chain (Spain) are formed by bioclastic sponge limestones (Yatova Fm.). The development of the sponge facies, however, appears geographically and stratigraphically limited by the development of clastic facies in the western part, and glauconitic limestones in the eastern part of the platform. The dividing palaeogeographic line between both facies seems to separate two distinct areas in the platform during the Middle and Upper Oxfordian: a western part, under the^slight influence of the near emerged massifs, and an eastern, distal part where glauconitic limestones are dominant. This suppossed palaeogeographic line also represents a sharp facies boundary during the Callovian-Oxfordian transition interval