A geophysical survey of the isle op man

A gravity survey of the Isle of Man was made during September and October, 1958. A Bouguer anomaly map was prepared which showed that the Bouguer anomaly over the whole of the Island has an average value of approximately 45 mgals. superimposed on this 'background' anomaly are six anomalies. Three of these lie along the main axis of the Island and are interpreted as being due to granites which are possibly joined at depth. The small basin of Lower Carboniferous sandstone at peel causes a small anomaly. At Jurby, the anomaly is probably due to basement uplift, or may be the 'background' anomaly for the whole of the Island. The Point of Ayre anomaly is caused by a trough of rocks of New Red Sandstone age, which deepens northwards. A fault with a throw of approximately 1500 feet and down throwing to the north, cuts these New Red Sandstone rocks.