Diagenesis-related differences in isotopic and elemental composition of late Campanian and early Maastrichtian inoceramids and belemnites from NE Belgium: palaeoenvironmental implications

Abstract

Late Campanian and early Maastrichtian inoceramid bivalves and belemnite rostra from three sections in the Liège and Limburg provinces (Belgium) are analysed petrologically and geochemically. Oxygen isotope ratios indicate that the early Maastrichtian material has been more affected by diagenesis than the late Campanian specimens, but data for belemnites do support the cooling trend from the late Campanian to the early Maastrichtian. Late Campanian and early Maastrichtian mean palaeotemperatures are deduced to have been lower than12.5 and 11.3 °C, respectively. Enrichment and depletion of elements, including rare-earth elements, and the generalised bright red-yellowish cathodoluminescence colour indicate cation-sensitive mobilisation processes during diagenesis.