Some mountains have rounded shapes, while others have steep slopes and sharp edges. Ulvanosa (1246 mos.) has both. The forms reflect the type of bedrock below, and the forces that were in effect when they were formed.
Siggjo is a cone-shaped, volcano-like mountaintop in the part of Hordaland where one finds the best preserved volcanic rocks. The rock types originate from one or several volcanoes that spewed out glowing lava and ash. But, the shape of the mountain, as it appears today, formed later and by completely different forces.
In 1868 the first stone workers came to Rubbestadneset to take out the granite for the Skoltegrunns Pier, predecessor of the Skoltegrunns wharf in Bergen. Later granite was also taken out from the area, around Innværs Fjord and UransvågenN. The activity probably peaked around 1900, with over 40 men at work. 15 years later, it was finished.
If we study the group of islands south of Selbjørns Fjord from the air or on a sea map, we will notice that many of the islands are elongated and lie systematically in rows. The islands are divided by long sounds, for example Trollosen, Nuleia and Hjelmosen, which are oriented in a south-southeast to north-northwesterly direction.
The highest mountainous area on Stord, including Kattnakken, Midtfjellet and Stovegolvet, has more in common with the mountainous terrain on the mainland than in the low coastal landscape of Sunnhordland. The volcanic bedrock together with the erosive powers of nature has resulted in a unique plateau landscape.
220 million years ago, glowing hot molten rock masses intruded into fractures in the earth's crust in the outer parts of Hordaland. Some of these are believed to have reached the surface and formed lava flows, which since have been eroded away by wind and weather. But, most of these flows solidified into diabase sills before they got to the surface.
At Flintaneset by Finnåsvika, in the centre of the municipality, we find the most beautiful and best preserved igneous rocks in western Norway. We must go to Hawaii or Island to find as fine structures as at Bømlo.