Glacial geology and palaeo-ice dynamics of two ice-sheet margins, Taymyr Peninsula, Siberia and Jameson Land, East Greenland

• Main Author: Alexanderson, Helena
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Quaternary Sciences, Department of Geology, Lund University 2002
• Subjects: Geology; ice dynamics; Pleistocene; Arctic Siberia; East Greenland; Sedimentology; Physical geography; Sedimentologi; pedology; geomorphology; klimatologi; kartografi; marklära; geomorfologi; cartography; Fysisk geografi; ice-marginal processes; glacial history; climatology; Arctic; Kara Sea; Greenland; Taymyr; Sund; Scoresby; Scoresby Sund; Jameson Land; Liverpool Land; Ugleelv; glacier; Ice Sheet; Taymyr Peninsula; Siberia
• Online Access: https://lup.lub.lu.se/record/464958; https://portal.research.lu.se/files/4769236/3159911.PDF

The North Taymyr ice-marginal zone (NTZ) on the Taymyr Peninsula, Arctic Siberia and the Ugleelv Valley on Jameson Land, East Greenland, have been investigated with the aim of reconstructing the glacial history, including depositional processes and environments. Geomorphological, sedimentological, stratigraphical and remote sensing methods have been combined to give a comprehensive view of developments in the two areas. Optically stimulated luminescence (OSL) and radiocarbon (14C) dates provide the chronological control. The Kara Sea shelf was glaciated three times during the Weichselian, each time with a smaller ice cover than before. The ice sheets caused a reversal of the fluvial drainage towards the south on the Taymyr Peninsula and, during the Early-Middle Weichselian, also the damming of proglacial lakes. The youngest ice-advance, but probably also the older ones, was warm-based and 'surge-like'. After it had reached its maximum position, the margin froze to its base and compressional flow took place there. The North Taymyr ice-marginal zone (NTZ) was initiated during an Early Weichselian retreat stage (c. 80 ka BP) and added to during the Middle (c. 65 ka BP) and Late Weichselian (<20 ka BP) ice advances, thus revealing a complex history. It comprises ice-marginal and supraglacial landsystems dominated by 2-3 km wide thrust-block moraines. Large areas are still underlain by remnant glacier ice and a supraglacial landscape with numerous ice-walled lakes and kames is forming even today. The proglacial landsystem is characterised by subaqueous or terrestrial environments, depending on altitude and time of formation. The sedimentary succession in the Ugleelv area comprises three tills, glaciolacustrine, glaciofluvial and aeolian sediments. The depositional history started in the early Saalian with a prograding delta in a lake dammed by an outlet glacier in Scoresby Sund. Soon thereafter, and also once during the Weichselian, Jameson Land was inundated by glaciers emanating from Liverpool Land in the east. ...