Hadde ikkje Hardangerfjordbreen mot slutten av istida rykt fram over fjordbotnen, ville Halsnøy ikkje eksistert som éi øy, men som mange småøyar. Breen skuva framfor seg så mykje leire frå havbotnen at Brattåsen, Toftåsen, Landåsen og Svartaberg vart samla i eitt landområde.
Ølve has a special soil type. Here one finds an extra hard clay soil. This is especially noticed by those who work with excavating for building foundations and the like. Often it is necessary to use especially big digging machines and sometimes even dynamite in order to break up the compact masses. The reason for this is the growth of the glaciers toward the end of the Ice Age: The clay, that was first deposited in front of the glacier, came under great pressure when the glacier later grew and slid out over the clay.
Fjøsanger is known among ice age researchers from around the world. Under an excavation in 1975-77, geologists from the University of Bergen found layers from the last interglacial, ca. 115 000 to 130 000 years old.
On the east side of Lake Skjelbreidvatnet, clearly visible along the road from Eikelandsosen, we notice a farm on a terrace above a grassy hill. The hill has the form of a broad shield; Skjelbreid (" Broad Shield") is the name of the farm.
Bays that are shallow far out into the sea, with fine sand and clay, are rare in Hordaland. Where they are found, the reason is usually that the edge of the glacier made smaller advances or stopovers when it calved back at the end of the last Ice Age. This is what happened at Vinnesleira.