SEMIQUANTITATIVE TECHNIQUES FOR THE IDENTIFICATION AND REMOVAL OF DIRECTIONAL TRENDS IN POTENTIAL-FIELD DATA

In this paper we present methods for the systematic identification of directional trends in potential field data based on analogies with the strike and dip of structural geology. Using this analogy we demonstrate how directional statistics methods familiar to geologists, namely the rose diagram and the stereo plot, may be used to identify directional trends in gridded potential field data. A new concept, an amplitude-direction plot, is introduced which enables us to separate features based on their combined amplitude and direction. Standard directional filtering techniques are then used to progressively remove identified trends following which the developed statistical methods are employed to decide whether any significant secondary trends remain. The techniques are illustrated first using synthetic data to demonstrate the method and are then applied to an example of real data from eastern Canada.