Traces of the Ice Age

The inland ice left marks on the terrain, when it moved across the landscape. Both on the Swedish and Finnish side, you can spot striations and grooves on rock surfaces. These striations reveal the different flow directions of the inland ice. Some of the striations are barely visible, but the ice sheet has also scraped some deeper ones. When looking for striations outdoors, make sure not to confuse them with cracks! You can see how striations are like stripes covering rock surfaces coherently, whereas cracks can appear randomly. It is easiest to discover striations when the light is at an angle, early in the morning or in the evening. 

Fields of stones

In some parts of the World Heritage Site, stones cover larger areas and form fields of stones. When the stones are larger in size, the fields are called boulder fields. The inland ice of the latest Ice Age transported the boulders here when it melted. Boulder fields can be a rough but spectacular sight, almost like a landscape from a science fiction movie. This vision is even stronger in the southern parts of the Kvarken Archipelago, where the inland ice has left behind loads of different sized boulders.

Moraine formations give the landscape a mosaic like feel

Different types of moraine formations are specific land forms on the terrain. Moraine formations are made up of till, an unsorted soil type left behind by the inland ice. Different moraine formations are a unique part of the Kvarken Archipelago, and some formations can be found on the High Coast as well.

De Geer moraines

The rather unusual name of De Geer moraine formations comes from its discovered, geologist Gerard De Geer. The narrow De Geer moraines form fields of parallel ridges, where the ridges are located 50 to 200 metres away of each other. One De Geer moraine can be up to a kilometre long and 2 to 5 metres high. De Geer moraines are a spectacular sight when they are surrounded by water like in Svedjehamn in the Kvarken Archipelago.  

De Geer moraines were formed deep in the water at the edge of the inland ice. Streams under the ice carried boulders, stones, gravel and finer material towards the ice edge. Just outside the ice edge, the water stopped flowing and the mixed stone material built up into a De Geer moraine ridge along the ice edge. A new De Geer moraine ridge formed to the place where the ice edge had moved to when the ice melted or and iceberg broke away from it.

Next chapter:
the land uplift phenomenon

This World Heritage Site has the world’s highest coastline and its shorelines gain new land each year. It is all thanks to the land uplift.
How does it work?