Upper Oxfordian to lower Kimmeridgian successions in the NE Iberian Range (E Spain): some new stratigraphical and palaentological data

摘要

Upper Oxfordian deposits in NE Iberian Range, from Hauffianum to Galar biozones, are mainly developed in terrigenous carbonate facies (the so-called Talamantes Member; Aldealpozo Formation), being markedly thicker in the NW sector of the platform. This terrigenous complex is interpreted as the front part of a pro-delta sedimentary system prograding towards the southeast. From Galar Biozone onwards sedimentation becomes progressively more carbonate. Bivalve associations reveal a progressive replacement of infaunal by epifaunal communities. Similarly, ammonite succession shows the replacement at this point of representatives of Ataxioceratinae genera Orthosphinctes and Subnebrodites by genus Planites. This fact, underlined by the record of Sutneria galar (OPPEL) in the Sot de Chera Formation, makes the Planula-Galar biozone boundary an acceptable possibility for the Oxfordian-Kimmeridgian stage boundary, thus giving further support to recent proposals within the Oxfordian-Kimmeridgian boundary Working Group of the ISJS.