FROM the lower Crati valley in Calabria, to the Peloritani Mountains in Sicily, metamorphic and intrusive igneous lithotypes represent the bulk of the Apennine mountain range. A wide cover of Tertiary sediment overlies these rocks, mainly along the coastal areas. The metamorphic and igneous rocks are in a weathered state. The weathering may be tens or even hundreds of metres deep. Deep weathering characterises crystalline rocks in a rapidly uplifting region such as Calabria.