Larger foraminifera and strontium isotope stratigraphy of middle Campanian shallow-water lagoonal facies of the Pyrenean Basin (NE Spain)

Abstract

The Upper Cretaceous Terradets Limestone of the south Pyrenean Basin consists of two subunits, named the Lower Terradets and the Upper Terradets. In the Lower Terradets subunit, sedimentological features and fossil content permit distinguishing mid-ramp, bioclastic shoal and inner-ramp lagoonal facies associations, each characterized by a distinctive larger foraminiferal assemblage. Mid-ramp facies contain epibenthic, relatively small foraminifera like Cuneolina cylindrica, Dictyopsella cf. cuvillieri, Pseudocyclammina sphaeroidea, Nummofallotia cretacea, Fallotia? sp., Pararotalia cf. tuberculifera, Praestorrsella roestae and Praesiderolites praevidali. Bioclastic shoal facies are dominated by Orbitoides cf. tissoti, Praesiderolites douvillei, and Pseudosiderolites sp. The inner-ramp lagoonal facies contain a rich and diverse assemblage of epiphytes, like Ilerdorbis decussatus, Dicyclina schlumbergeri, and Cyclopsinella roselli n. sp., and epibenthic foraminifera, like Calveziconus lecalvezae and Orbitokathina campaniana. Strontium isotope stratigraphy indicates a middle Campanian age for the Lower Terradets limestone.