At Berge it as if nature has forgotten a piece of the gabbro that once covered the entire area. This gabbro once belonged to the old sea floor from which Bømlo is formed. During the mountain-building process the gabbro was thrust over a younger limestone and phyllite.
In the summer of 1882 the geologist pioneer Hans Reusch found fossils in the limestone, among others the shell remains of brachiopods that lived in a shallow sea about 450 million years ago. It is unbelievable that these fossils are preserved, considering the enormous pressure the limestone was exposed to when the gabbro was thrust over. Since the gabbro was thrust over the limestone after the fossils were deposited, the tectonic activity must have occurred later than 450 million years ago.
