Palaeoenvironmental Changes and C-Isotope Stratigraphy in the Alarcón Formation Stratotype (Upper Cenomanian–Lower Coniacian), Iberian Ranges, Spain

Abstract

This study analyses the sedimentary facies, palaeosols, and δ13C stratigraphy of the Alarcón Formation in its stratotype in the Iberian Ranges (Spain). The aim is to characterize the palaeoenvironmental changes that occurred in the shallow-marine carbonate environments of central Iberia during the late Cenomanian to early Coniacian. These changes, recorded in seven transgressive–regressive cycles, are interpreted in the framework of regional sea-level variations, local subsidence, and climate. The possible influence of supraregional changes, such as those related to Oceanic Anoxic Event 2 (OAE2), on the sedimentary succession of the Alarcón Formation is also analysed and discussed.