THE INTERPRETATION OF MAGNETIC ANOMALIES DUE TO DYKES*

Based on simple scaling laws, a method is developed for the routine interpretation of magnetic anomalies arising from uniformly magnetised dykes. The method can be applied to any observed component of the field, i.e. the vertical, horizontal or the total field anomaly and it is applicable for any resultant direction of magnetisation of the dyke itself and for any strike direction. The necessary data for the interpretation are given in the form of curves covering a range from o up to 15 for the ratio of the thickness of the dyke to the depth to its top. It is also shown that, by integrating in a suitable manner the observed anomaly due to inclined bodies having a horizontal upper surface and enclosed by two pairs of parallel and inclined planes, a curve is obtained which corresponds to a dyke anomaly and which can be interpreted by the same technique.