The sedimentation pattern of the last deglaciation and postglacial phase in a high-arctic valley: Endalen, Spitsbergen

• Main Author: Soltvedt, Stian
• Format: Master Thesis
• Language: English
• Published: The University of Bergen 2000
• Subjects: VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Sedimentologi: 456; Adventdalen; Arctic; Endalen; Raised Beach; Ice Sheet; Spitsbergen
• Online Access: https://hdl.handle.net/1956/1804

The present study, focused in the valley-side gravel fans in the eastern part of Endalen and the adjoining side-slope of Adventdalen, has contributed to an understanding of the spatial pattern of the late Weichselian deglaciation and associated meltwater drainage in a 3rd-order and a 2nd-order valley and adjacent mountain plateau in central Spitsbergen, Norwegian high-Arctic. The author’s fieldwork in 1998 was focused on the following main topics: (1) the mapping and chronology of postglacial sediment accumulations, with special emphasis on the development history and depositional processes of the valley-side gravel fans; (2) the snow-cover conditions on the valley-side slopes during the winter to autumn season 1998, including comparative photographic documentation and fixed-point snow thickness measurements; and (3) the assessment of the intensity, routes and controlling factors of the downslope transfer of sediment and water, including the recognition and spatial pattern of meltwater palaeoflow scours and their significance for the reconstruction of the ice-sheet retreat. The analysis of infrared aerial photographs has proved to be very useful in deciphering the areal pattern of meltwater palaeodrainage and in the recognition of other glacial/postglacial geomorphic features. Arrays of surficial palaeochannels are recognizable on the eastern plateau of Endalen, trending NW and lacking any obvious water catchment today. These scours are attributed to the meltwater runoff during the early Holocene deglaciation. The morphological mapping revealed also relict late-glacial deposits in the form of a lateral moraine and several raised beach terraces near the mouth of Endalen, but no preserved glacigenic diamicton deposits have been recognized on the adjacent eastern plateau. Erratic cobbles and boulders have been found on western plateau, directly outside the Endalen drainage basin, which indicates that the mountain plateaux were covered by the glacier. Some long-transport erratics, derived probably from the eastern ...