GIS-based 3D sedimentary model for visualizing complex glacial deposition in Kersilö, Finnish Lapland

Complicated Quaternary sediment strata have been preserved within the ice-divide zone of northern Finland because of weak glacial erosion. Geographic Information System (GIS) databases, 3D modelling and ground penetrating radar surveys were used to construct the 3D structure of unconsolidated sediments and bedrock topography for Kersilö, Sodankylä, to provide information for freshwater management and environmental studies in the mineral exploration area. The model was created using a combination of explicit and implicit modelling covering an area of 10.5 km2. The surficial deposits in the study area are a few metres thicker than their average thickness in northern Finland. They include three till units and four sandy or gravelly units. Fluvial action has repeatedly deposited sorted sediments in the channel valley of the Kitinen river. Basins in the bedrock have preserved thick sediment packages (> 15 m), indicating that the bedrock topography controls the sedimentary features. Aquifers in the area are small and disconnected, and perched aquifers exist due to the low hydraulic conductivity of interlayered tills.