Premosello

In Premosello there is an extraordinary outcrop that reveals thecontact between the peridotites of the lithospheric mantle and the mafic granulites of the lower continental crust, which have been brought to the surface from a depth of 30–35 km by tectonic and erosive processes.

The lower part of the rock face consists of a homogeneous black serpentinised peridotite (a transformation involving metamorphism and hydration of the original rock). The upper part of the outcrop consists of a mafic granulite, probably derived from a layered gabbro. The contact is a surface inclined at 35° towards the north.

This surface can be regarded as representative of the Mohorovičić discontinuity (or simply the Moho), i.e. the boundary between the crust and the mantle, and has been includedin the inventory of geosites of international interest maintained by the International Union of Geological Sciences (
, IUGS ) (International Commission on Geoheritagehttps): link.

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