SHAPE-ANALYSIS OF AEROMAGNETIC ANOMALIES IN THE SOUTHERN ITALIAN REGION FOR THE EVALUATION OF CRUSTAL BLOCK ROTATIONS

An extensive analysis of aeromagnetic data from the Italian region is presented, regarding the evaluation of the azimuthal direction of the total-magnetization vector. A method based on the Zietz and Andreasen (1967) correlation between anomaly shape and direction of the total magnetization vector was used. A discussion related to possible traps in using this method is presented, with the aid of several tests on synthetic anomalies. The analysis points out a number of anomalies revealing abnormal directions, either SW-NE or SE-NW, which were used to divide the investigated area into five regions with different trends. Finally, assuming elevated Koenigsberger ratios for the source-rocks, the declinations of the remanent magnetization vector were judged very similar to those estimated for the total-magnetization vector. Thus, by comparing these values with the normal declination of the area, rotation values of the crustal blocks related to the investigated anomalies were proposed. Finally, these were compared with the available geological and palaeomagnetic information and significant correspondences were found.