A consistent magnetic polarity stratigraphy of late Neogene to Quaternary fluvial sediments from the Heidelberg Basin (Germany): A new time frame for the Plio–Pleistocene palaeoclimatic evolution of the Rhine Basin

• First magnetic polarity based chronostratigraphy for the Heidelberg Basin.
• The resultant age model enables the determination of accumulation rates.
• The study provides a time frame for the palaeoclimatic evolution of the Rhine Basin.

This work presents the results of a magnetostratigraphic survey performed on 1150 m of core material from three sites within the Heidelberg Basin. The cores intersect one of the thickest continuous accumulations of Plio–Pleistocene fluvial sediments in western Central Europe. The resultant magnetic polarity stratigraphy includes every Quaternary polarity chron, thereby providing constant age constraint down to the Gauss–Matuyama Boundary (2.58 Ma). Older deposits cannot be unequivocally dated; instead, various age–depth models are discussed. We base our chronostratigraphic interpretation of the successions tentatively on three assumptions. A) The accommodation was almost constant over time. B) Hiatuses in the duration of subchrons (on the order of 0.2 Myr) may occur, and the actual step-like age–depth relationship is best depicted as a smooth curve with almost constant slope. C) Long chrons and subchrons have a higher preservation potential than shorter polarity intervals.The stratigraphic scenarios with the highest probability – based upon our three assumptions – lead to minimum ages of > 5.235 Ma and > 4.187 Ma for the oldest parts of the Viernheim and Heidelberg cores, respectively. Consequently, this study provides the first consistent magnetic polarity stratigraphy for quasi-continuous sequences of late Neogene to Quaternary fluvial sediments in the Rhine Basin and generally in western central Europe. This methodologically independent chronostratigraphy supplies an urgently required temporal model for on-going tectonic and sedimentological studies and the reconstruction of the palaeoclimate since the Pliocene in this part of Europe.