Glacial geology of the Råda valley, Varmland, western Sweden

The Råda valley extends from Lake Rådasjön in the north to the Brattforsheden delta complex in the south. Three parts are characterized by different glacial deposits: the southernmost part is the delta complex reaching to the sea level of that time, the highest coastline. A middle part is a valley fill of glacial silt covered with sand. The northern part is occupied by a series of lakes, separated by thick deposits of sand reaching slightly above the highest coastline, and partly surrounded by lower sand terraces. These deposits and the glacial morphology give the following picture of the process of deglaciation. The Brattforsheden delta complex was formed when an ice tongue developed in the valley due to the waning of ice in the surrounding highland. From this stage on, a series of long, narrow and flat ice bodies was isolated in the valley and probably remained there for some time. The silt is interpreted as the most distal sediment corresponding to a delta of coarse gravel and stones on the eastern side of the northernmost part of the Råda valley. Sand was deposited upon the ice bodies, along their sides and in crevasses between them during the break-up of the ice. This development offers a model applicable to the long, narrow Klarälven valley extending northwards from the Råda valley.