An integrated approach to reconstruct the Saalian glaciation - GIS-based construction of a new phase model for the Netherlands and NW-Germany

Abstract

Some 170,000-150,000 years ago (during MIS 6), large ice masses last covered the Netherlands and NW Germany (Saalian Drenthe Substage). This left many geomorphological features in the landscape, e.g. ice-pushed ridges, sandurs and glacial basins. Throughout the 20th century extensive research has been revealed on this geomorphological assemblage and produced interpreted sequence of glacial events, known as glaciation phase models. The successive competing phase models of the 1960ties to the 1990ies each appear biased to specific features, subregions and types-of-data. At present, new data and insights exist that have risen since the construction of the currently established models. In this research the sequence of events was newly reconstructed, aiming to unify the evidence in NW Germany with that in the Netherlands. I collected geological-geomorphological evidence (literature inventory) and newly interpreted high-resolution elevation data in an inventory GIS. The conceptual phase models and related glaciological processes during the glaciation were reviewed, responsible for the eventual ice-margin landscape. Elements of 'classic' knowledge and new lines of reasoning are each outlined. The newly constructed phase model recognises three phases towards maximum ice-sheet extent, one transition phase and two deglaciation phases. The GIS stores the preferred phase model, as well as earlier interpretations.