The drone-borne magnetic survey as the optimal strategy for high-resolution investigations in presence of extremely rough terrains: The case study of the Taverna San Felice quarry dike
Filippo Accomando, Antonello Bonfante, Maurizio Buonanno, Jacopo Natale, Stefano Vitale, Giovanni Florio
Abstract
In the Taverna San Felice limestone active quarry (Italy) excavation has progressively exposed a magmatic dike embedded in a calcareous succession. The dike outcrops are scattered among the high vertical steps of the quarry, whereas outside the excavated area the steep mountain slope covered by a dense bush vegetation make direct inspection and geological mapping a challenging task. To map the areal extension of the dike and to define its direction and its relationship with tectonic lines over an area larger than the quarry, a magnetic survey was performed. Given the above-mentioned extremely rugged terrain, a UAV-based magnetic survey was the preferred acquisition strategy. Data were acquired by rigidly fixing the magnetometer to the UAV landing sled, using a sensor with a very high-frequency (1000 Hz) acquisition rate. The acquisition strategy and some simple processing steps resulted in a detailed drone-borne total field anomaly map. This dataset allowed for a mapping of the dike outside the quarry area and the identification of a vent fed by the dike. The 2D forward modelling of the magnetic data was constrained by a field estimation of the intensity of the total magnetization and by the depth to the dike's top, in places where it is outcropping.