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 demonstra te how directional statistics methods familiar to geologists, namely t he rose diagram and the stereo plot, may be used to identify direction al trends in gridded potential field data. A new concept, an amplitude -direction plot, is introduced which enables us to separate features b ased on their combined amplitude and direction. Standard directional f iltering techniques are then used to progressively remove identified t rends following which the developed statistical methods are employed t o decide whether any significant secondary trends remain. The techniqu es are illustrated first using synthetic data to demonstrate the metho d and are then applied to an example of real data from eastern Canada.