Quaternary landscape evolution and tectonics in Central Germany – A case study of the Harz

Abstract

The Harz is one of the highest mountain ranges in Central Germany, featuring a flat, plateau-like morphology that is elevated above the surrounding regions. Although its morphology has been subject to multiple studies since the early 20th century, knowledge about its development since the late Cretaceous is still incomplete. We present a comprehensive geomorphological study of the Harz Mountains, benefitting from the availability of digital elevation data and modern computer-based geomorphological analyses. We use morphometric indices, drainage network analyses, topographic swath profiles, geological properties and field investigations to decipher the role of neotectonic and climatic forces in its evolution.The results indicate that glacial isostatic adjustments forced the uplift of the Harz due to inland ice masses covering the Subhercynian basin in Pleistocene. This process reactivated inherited tectonic structures along the Harz boundaries. The major uplift took place along the southern Harz boundary, tilting the entire Harz surface towards north and forcing a disequilibrium of the drainage network. A combination of tectonic uplift and post-glacial erosion of the Subhercynian basin sediment cover shaped the steep scarp at the Northern Harz boundary. The location of uplifted paleo-surfaces and their morphologic properties indicate that the Harz block is internally divided into two tectonically decoupled blocks along a NNW-SSE-striking lineament. Our results help to understand the landscape evolution of the Harz block and provide additional information about neotectonically active structures. The latter is of interest for the ongoing search for nuclear waste deposit sites in Germany.