Age and palaeoenvironment of the enigmatic Arternian Interglacial — Evidence from the Muschelton at Voigtstedt/Hackelsberg (Thuringia, Central Germany)

Abstract

The Arternian Interglacial has been established on the basis of a pollen record within the Muschelton (=Shell Clay) horizon near Voigtstedt (type locality) in the surroundings of Artern in Central Germany. This horizon is older than the early Middle Pleistocene Voigstedt/Lehmzone (=Loam Zone) layers, which overlie the Muschelton. Due to the lack of a comprehensive fossil record, the age of the Arternian Interglacial has long been disputed, as has its palaeoenvironmental conditions. Here we present the results of new interdisciplinary studies from new exposures of the Muschelton at Voigtstedt/Hackelsberg. Palaeomagnetic screening revealed dominantly reversed polarity of the Muschelton, partly overprinted by normal magnetisations. Fossil content consists of identifiable plant, mollusc, ostracod, fish, small and large mammal remains.The stratigraphic range of the recorded taxa, in combination with the palaeomagnetic reverse polarity and amino acid racemization studies, indicate an Early Pleistocene age for the Arternian Interglacial, within the range of MIS (marine isotope stages) 29–21 (c. 990–810ka). In contrast to interpretations in former studies, our investigations of the Muschelton from Voigtstedt/Hackelsberg do not indicate subarctic climate prior to or following a clearly separated interglacial. As evidence for high summer temperatures was present throughout the Muschelton sequence, the changes between cold and temperate stages in the pollen record can be best explained by changes in continentality. This result confirms climatic inferences for pollen records of other Early and early Middle Pleistocene sites in Central Europe.