A gravity survey combined with geological field work has been made of the ultramafite complex of Åheim. The study shows that the exposed ultramafic bodies are in all probability all part of one body which has a depth of about 1 km. The central gneissic mountain, Helgehorn, is probably 'floating' on top of this ultramafic body. The Bouguer anomaly contours suggest an eastward extension of the ultramafic body at depth. The total excess mass of the ultramafite complex is estimated to 1.2-1.5X 1010 tons and the volume is approximately 25-30 km3.
Gravity investigation and geological interpretation of the ultramafite complex of Åheim, Sunnmøre, western Norway