Gravity study of the Norcia intermountain basin (Central Italy).

Abstract

We present the results of a gravity investigation conducted in the Norcia Intermountain Basin (central Italy) in order to obtain a subsurface picture of its structural setting and to estimate the thickness of the Quaternary infill sediments. Our survey resulted in 210 measurements, placed evenly in the whole Norcia Plain. We produced gravity anomaly maps that show the Quaternary thickness spatial distribution within the basin and identify buried faults affecting the bedrock in the northern basin sector. 2.5D models along close spaced profiles were used to construct a 3D density model and a map of the bedrock top surface elevation. Our results suggest that the northern sector of the Norcia Intermountain Basin has been affected by a strong tectonic activity with respect to the southern sector where the top of the bedrock is eroded and buried by a thin layer of alluvial gravels.