The youngest time interval of the Cretaceous Period is known as the Maastrichtian, in reference to the shallow-marine strata outcropping in the area surrounding the city of Maastricht, in the Netherlands-Belgium border region. While the type-Maastrichtian strata have yielded a wealth of paleontological data, comparatively little geochemical work has so far been carried out on this succession. To date, age assessment of the type-Maastrichtian, and stratigraphic correlation with sections elsewhere, have largely been based on biostratigraphy and preliminary attempts at cyclostratigraphy. However, these techniques are hampered by bio-provincialism and the presence of stratigraphic gaps in the succession, respectively. In recent years, stable carbon isotope stratigraphy has proven to be a powerful tool for correlating Upper Cretaceous strata on a global scale. When integrated with biostratigraphy, carbon isotope stratigraphy can be used to test the synchroneity of biological and climatic events across the globe and to reconcile inter-regional biostratigraphic schemes. Therefore, we have generated the first high-resolution bulk stable carbon isotope stratigraphy for the type-Maastrichtian, using an extensive sample set acquired within the context of the Maastrichtian Geoheritage Project spanning approximately 100 meters of stratigraphy at the Hallembaye and former ENCI quarries. In combination with bulk major and trace element data generated using mu XRF, this record presents the first high-resolution chemostratigraphic survey for the type-Maastrichtian. The mu XRF-based element profiles through the type-Maastrichtian succession reveal variable fluxes of terrigenous input into this carbonate system over time, marking three distinct stratigraphic sequences, separated by sequence boundaries at the Froidmont, Lichtenberg and Vroenhoven horizons. In addition, the carbon isotope profile records the Campanian-Maastrichtian Boundary Event (CMBE) and the Mid-Maastrichtian Event (MME) in the Maastrichtian type area for the first time. Our refined age model allows for global correlation between the type-Maastrichtian sequence and Maastrichtian successions worldwide and places the abundant paleontological records from the type-Maastrichtian in a global context. |
