Rocksjöliden

Rockliden is Västernorrland´s only known significant massif of sulphide ore. The ore was found in the middle of the 1980s by Boliden AB. After thorough surveys, which included stripping off the overlying moraine, bore holes, analyses and test concentrations it was shown that the ore contains just over 2 million tonnes of ore with good levels of zinc, lead and copper. However, the surveys also showed that the ore contains disruptive elements which mean that the ore is now not worth extracting. Isotope surveys have shown that the ore has about the same age as other massive sulphide ores in Bergslagen and the Skellefteå field, i.e. it is about 1,900 million years old.

Because the entire ore body, including the underlying igneous rock types that are partly hydrothermally metamorphosed, as well as the overlying sedimentary rock types, is exposed and no mining activity has taken place, the Rockliden ore is by far the best site in Sweden at which to study the anatomy of a typical massive sulphide ore.

The ore and the surrounding rock are folded and tilted, so that everything that was originally the seabed and horizontal, now slopes steeply to the north-east. This means that it is possible to see a fine cross section of the ore, with the oldest rocks, igneous rocks that have more or less metamorphosed, on the left side of the stripped area, the massive sulphide ore in the middle of the strip and sedimentary rock types, mainly clay slates, on the eastern part of the strip.

The County´s Bedrock

Fact Sheet The Strukture of Bedrock