Paleoenvironmental reconstruction of the cold mid-Paleocene: Comparing the New Jersey shelf and the North Sea basin

Abstract

Mid-Paleocene (62-58Ma) is a relatively cool period which was scarcely studied. Paleoclimate reconstructions of the relatively cool period mid-Paleocene can provide a better insight of the transition from green house towards Eocene hothouse. Due to the low sea level, sedimentary archives that capture this time interval are scarce. This study provides a complete biostratigraphy framework and δ13Corg sequence of the Paleocene in the North Sea basin core 22/10a-5, and also investigated the paleoenvironmental change dinocysts assemblages. Results from the North Sea Basin core were compared with new analyses on sediments from the Eastcoast US (New Jersey shelf Bass River Core) for New Jersey shelf ODP 174AX which has been intensively studied for the PETM. The integration of TEX86-based SST reconstructions from Bass River with existing records in other regions imply that there is a highly reduced meridional temperature gradient occurred in the southern hemisphere while the gradient in the northern hemisphere was large. This is very likely due to the presence of ice sheet in the southern hemisphere. Palynological study revealed that sea level changed synchronously in both sites and low marine paleo-productivity during cold low sea level period. However, productivity would increase in the climate warming stage as a consequence of intensified precipitation and terrestrial input. Latest Danian event (LDE) and North Atlantic Igneous Province (NAIP) were also reflected in the North Sea section.