Geostructural features of the middle Tirso valley from seismic reflection data

The main Geostructural features of the central north sector of the middle Tirso valley (Central Sardinia) and the seismic characteristics of the volcanic sedimentary deposits of the area within the upper first 2 km have been determined from reflection seismic data along a 4 km profile. The data were acquired with a Geometrics ES-2420 seismograph and processed on an IBM 3090 computer with an FP array processor using the Halliburton Geophysical Services seismic package. Five seismic units have been distinguished on the basis of configuration, continuity, amplitude and frequency of the reflections. An integrated analysis of the seismic and geological data contributes to our knowledge of the main deep Geostructural features of the study sector and to a correlation of the seismic units with the stratigraphic units outcropping in this sector. The dislocation of the Paleozoic basement was found to be greater than expected from the surface observations. From correlation of the seismic units with the stratigraphic units outcropping in this zone, we deduce that the lower ignimbritic series are thicker in depth than at the surface, both within the study area and in other sectors of Sardinia.