Marginal behaviour of the last Scandinavian Ice Sheet during its final termination and deglaciation over Northeastern Germany

• Main Author: Albrecht, Joachim
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Quaternary Sciences, Department of Geology, Lund University 2004
• Subjects: Geology; Fysisk geografi; geomorfologi; climatology; cartography; pedology; geomorphology; Physical geography; Marginal dome; Deglaciation; Clast lithology; Clast fabric; Germany; Pomeranian; Weichselian; Lithostratigraphy; marklära; kartografi; klimatologi; Sedimentology; Sedimentologi; Ice Sheet
• Online Access: https://lup.lub.lu.se/record/466607

This thesis presents results from studies on geomorphology, lithostratigraphy and ice flow patterns during the final termination and deglaciation of the last Scandinavian Ice Sheet in NE Germany. Ice flow patterns derived from till fabrics and glaciotectonical data indicate that short-lived marginal domes had formed during the advance and the retreat of the last Scandinavian Ice Sheet in NE Germany. This interpretation is supported by several events with ice flow directions, which deviate from the otherwise prevailing movement direction from the NNE through NE. The area north of the Pomeranian terminal moraine is divided into a hummocky moraine terrain in the SW and a cover moraine terrain in the NE. A regional lithostratigraphy has been established, which is based on lithological, sedimentological and glaciotectonical data from open sections. One Weichselian basal till, overlying glaciotectonically deformed outwash sediments, has been found in the cover moraine area. Till fabrics imply an initial ice movement direction from the SSE through E. Glaciotectonically dislocated sediments, eg. rafts of Tertiary clay, Tertiary sand, pre-Weichselian till and Eemian peat, occur occasionally in the entire study area, obscuring the stratigraphical record. These sediments must therefore be handled with caution when used as stratigraphical marker horizons. The sediments in the hummocky moraine area consist of out-wash and mass movement deposits related to the deglaciation after the Pomeranian stage. Some of the sites in the hummocky terrain also show implications of active ice movement from the SSE and SSW during dead-ice decay. An event-stratigraphical model is erected, which is tested against existing numerical and qualitative models. The existence of marginal domes is confirmed by several numerical models, most qualitative models are ambiguous to dome-build up, however. The marginal dome theory is controversial, although it provides an opportunity to explain frequently occurring deviating ice flow directions in NE Germany.