Moho deepening and shallow upper crustal delamination beneath the central Apennines

摘要

Geologic interpretation of seismic data along the eastern half of the CROP 11 deep seismic reflection profile, running across the central Apennines, indicates that the Adriatic Moho deepens gradually from 34 km in the foreland areas to 47 km beneath thé core of the belt. This deepening is in agreement with local Moho depths estimated from teleseismic receiver functions at several stations installed along the CROP 11 profile. On the contrary, DSS (Deep Seismic Soundings) data image the Moho at shallower depths. The deepening of the Adriatic Moho illustrated in this paper supports the westward downgoing of a portion of Adriatic continental crust and is consistent with the regional gravity anomalies, provided that very high-density rocks are present above the Moho at the core of the central Apennine belt. We discuss geophysical and geologic data in the framework of alternative models of delamination of the Adriatic crust at different depth.