Morafältet

An old ice edge delta. In the mountains there are many living deltas, which grow and are built on by mud from today's glaciers. The delta that was formed during the ice age, at the edge of the ice sheet, has today often ended up on dry land - one such is the Morafältet.

Ice Age landscape The last ice sheet disappeared ten thousand years ago. Masses of turbid meltwater from the glacial ice brought with it gravel and sand that could form ridges and deltas. The Delta The delta is formed by silt-rich glacial rivers as they flow into calm water, slow down and lose power. A delta is a fan-shaped landform where the river divides into winding branches. A very large ice river followed the Österdalsälven valley. When it flowed into the bay that later became Lake Siljan, formed a gigantic icerand delta, one of Sweden's largest. The delta follows the depression formed by the Siljans ring, which has its background in the meteorite that struck 380 million years ago in what is now Dalarna. When the land rose, the gulf became a lake, Siljan, and the delta ended up on dry land. Death ice pits and flying sand dunes Floating icebergs stranded in the delta area. When they melted away, large death ice pits remained in the sand. And when deltaic sand ended up in the dry air, the wind could lift the sand and build towering flying sand dunes. Bonäsfältet is Scandinavia's largest dune field. Today's landscape Now the Österdalälven burrows into the sand it itself brought there at the end of the Ice Age. And pine forests grow on the flying sand dunes.