Structural setting of the Trieste area from gravity modelling

An extensive onshore gravity survey, with a nominal density of 1 station/km2 comprehending 177 stations, has been carried out to improve the existing lowresolution data set in the area surrounding Trieste (Italy). The survey has been processed and the Bouguer anomaly computed over the entire area and then interpreted. The Bouguer anomalies show a negative gravity trend going from south to north probably associated with the regional direction of the main geological structures. According the gravity model computed along six profiles, the regional gravity trend and the minimum negative Bouguer anomaly are related to folding phenomena of the flysch units in the Panzano Gulf and thrusting of limestones over flysch rocks along a fault that outcrops in the “Costa dei Barbari” and runs near the coast southward. Intraformational deformation cannot be excluded and should be taken into consideration to explain the increase of thickness of flysch northward.