Koviken

The borderland between older bedrock and younger magma chambers

At Koviken runs the border between the 1,900 million year old bedrock and Ragunda’s 1,500 million year old magma chambers. The chambers were formed of masses of molten rock, magmas that pushed upwards from within the earth and gathered a few kilometres below the earth´s surface. Since then all the material that had been above the chambers has eroded making it possible for you to look right into them.

Part of a magma chamber

Koviken is part of the same magma chamber as many other of the sites in the geopark, including Bäckerhällan. When you look out over Lake Gesunden you will see Bäckerhällan in the border area where the flatter and older bedrock is changing into higher hills. This view will give you an idea of the size of the magma chamber.

Inside the magma chamber you can see various geological phenomena and species of rock. Here however they are not as obvious and easy to spot as at other sites in the geopark for example Stadsberget, Forsnacken, Prästberget 1 and Trätojordsbacken.

*The borderland between older bedrock and younger magma chambers.* Photo: Peter Ladan.

*Magmatic breccia.* Photo: Katarina Söderlund.

*Rapakivi granite.* Photo: Katarina Söderlund.

1,900 million year old bedrock

The 1,900 million year old bedrock consists of large quantities of sediment that were deposited on the bottom of the sea for many hundred millions of years. The sediment stemmed from volcanic rock and older granites from the surroundings. The material was abraded into gravel, sand and mud which were carried by rivers and the wind into the sea.

On the bottom of the sea thick layers of sediment were formed. As the layers of sediment grew thicker, they were compressed through their sheer weight, and eventually the sediments transformed into rock.