Exposure is very unevenly distributed within the area of the Institute of Geological Sciences Sheet 128 as there are large areas of peat and sea. However, the aeromagnetic map shows a complex pattern of anomalies covering the whole area. Ground traverses with a magnetometer show that most of the positive anomalies are caused by rocks which crop out but are very poorly exposed. The outcrops were delineated with the aid of magnetometer traversing. The occasional exposures reveal that the rocks causing these anomalies are magnetite-rich schists of pelitic and greenschist types and serpentines. Ground traversing with a magnetometer shows that the magnetic schists form narrow bands which act as marker horizons in poorly exposed areas. The pattern of aeroanomalies caused by the magnetic schists and the non-magnetic rocks with which they alternate continues over the sea and enables predictions to be made about the geology of the sea areas.