The sub-Cambrian peneplane formed in Precambrian crystalline rock is here in mount Lugnåsberget overlaid with sedimentary rocks. The Minnesfjället mine is one of the few places where it is possible to see the contact zone between the Precambrian bedrock and the oldest Cambrian deposits from below. The site is well known for its fossils, trace fossils and sedimentary structures, showing early life and palaeoenvironments. It also forms part of the mining history in Sweden, as mill stones have been quarried here for long time.