| dc.description.abstract | An early Holocene glacier front deposit of a lower outwash fan and an upper delta, at Vie sandpit next to the town of Førde in Sunnfjord municipality in western Norway has been investigated using various fields methods, including ground-penetrating radar, on-site logging, and photography. The Vie deposit is an active sandpit, situated southeast of Førde town centre, located on the right bank of the Jølstra river which runs from east to west through a typical glacier-formed valley with outlet into the Førde Fjord.
The goal of the research was to understand various dynamics of glacial front deposited sediments, with focus on sedimentary structures and architecture. Such understanding will enhance our understanding of the final stages of basin filling in front of a receding glacier, including basin water level changes and effect of isostatic uplift.
The observations made in the Vie sandpit, show a high-energy and high-density, sediment laden glacifluvial flow, leaving a sequential deposit of a lower early structure and a later upper structure. The upper structure is characterized by a migrating channels and unconformities, with seasonal changes based on recorded GPR-data. The lower sediment deposit structure is characterized by lens shaped coarse sediment materials surrounded by fine and coarse grained sands in the deltas lower fine grained foreset to bottomset transitions zone exposed in the Vie sandpit. Debris flows and deformations are supported by GPR data in the topset and foreset areas.
Temporal constraints are considered for the main deposited sediment sequences as they are defined by the (i) positioning of the retreating glacier front and season variations, (ii) the elevation of current day topography in Førde in relation to sinking basin water levels, (iii) the transition from lower sediment deposit, to upper sediment deposit and their respective similar and different characteristics, (iv) the abrupt termination of active glacial sediment deposition in Vie sandpit, Løland due to the distal glacial front.
In other words; Research what was deposited in Vie-Løland, Førde, how was it deposited and what supports such a conclusion. | |
