The Sandstenskleven cleft at Hällekis are made up of layers of rock that were deposited on top of the bedrock over 500 million years ago and now form the steep shoreline of Lake Vänern, north of Hällekis campsite. At this time our continent lay at a southerly latitude of 40 degrees.
A thin layer of a rock known as conglomerate, exposed along the shore line, is covered by thick beds of sandstone, all deposited in the shallow waters of a sea about 540 million years ago. The sandstone is mostly made up of grains of quartz, i.e. an original sandy seabed, in which ripple marks reveal that water was quite shallow. In the more finely grained layers of sandstone that contain clay, there are traces of organisms that lived at the bottom of the sea. This type of sandstone takes its name, Mickwitzia, from one of these creatures, a type of brachiopod.
The easiest way to reach Sandstenskleven is from the path that runs along the shore, north of Hällekis Camping.