Holmengrå is the only place in Hordaland where we find traces of the abrasion that is supposed to have transformed Western Norway from a Himalaya-like high mountain landscape during the earth's Paleozoic Era, to a flat lowlands terrain during the Mezosoic Era. Just 400 million years ago, large and small stones plummeted down from the high mountains. Some of these stones became incorporated into the conglomerate bedrock on Holmengrå.
The eclogites in western Norway were formed when Precambrian basement rocks were squeezed and pressed down under great pressure deep under the Caledonian mountain chain. The process may well have triggered some of the deepest earthquakes the world has ever known. The clearest traces of this drama are found in and around Mt. Eldsfjellet, in peaceful Meland.
Large quantities of nickel ore have been mined from Litlandsvatnet, between Lonevågen and Hosanger. The discovery was made in 1875. During the period of operation from 1882 to 1945, 4170 tonnes of pure nickel were extracted from 462 000 tonnes of ore, a large production by Norwegian standards.
On Vågenes, on one of the prominences out toward Eitrevågen, one finds garnets in anorthosite. The garnets are both older, and not least bigger, than average.
The mountains of western Norway are lovely to wander in. In Cambro-Silurian time it was the mountain itself that wandered. The mountain, or more correctly the bedrock, first moved eastward, then back a bit westward again. All this rocking back and forth in the mountains ended about 400 million years ago.