The Paleocene/Eocene-boundary interval of a Tethyan deep-sea section (Austria) and its correlation with the North Sea basin

Abstract

Abstract The Anthering-section is one of the most expanded upper Paleocene - lower Eocene sedimentary sequences known to date and records several of the Paleocene/Eocene boundary events, including the delta 13 C isotope excursion. Within 250 m of abyssal-plain deposits, calcareous mud-turbidites originating from the basin slope alternate with hemipelagic claystones. The average rate of sedimentation for the lower part of Zone NP9 is calculated at 22.7 cm/ky and for the upper part of Zone NP9 and Zone NP10 at 9.1 cm/ky. In the lower part of Zone NP10 closely spaced bentonite layers occur which mainly display immobile element concentrations typical for alkaline basalts. However, the thickest bentonite (X1), situated at the base of the ash series, plots into the trachyte field. Dinoflagellate stratigraphy strongly suggests that the ash-series at Anthering is synchronous with the main occurrence of ash layers in the North Sea region which display a comparable chemical composition. The biostratigraphical and geochemical correspondence of both ash-series point to a common source of magma. Especially, a correlation of layer +19 of the North Sea region with layer X1 at Anthering seems probable. We therefore consider the bentonites from the Anthering-section as distal deposits of the "positive" ash-series of the North Sea region which obviously represent unique and widespread correlation tools.