The coarse-grained metagranite with large crystals of blue amphibole is observed in this locality. They are aligned parallel to the main schistosity which is folded. The appearance of blue amphiboles shows that the rock was subjected to high-pressure metamorphic conditions during the subduction of the Tenda Massif.
In Corse gneisses and granitoids are representing the continent-derived Tenda unit. On a larger scale, it forms a long culmination of metamorphic rocks located between autochthonous/parautochthonous units on the west and the Schistes Lustres nappe system on the east.
The roadcut is characterized by granitoids which are 280-312 Ma old (Cocherie et al., 1994). As a metamorphic indicator of continental subduction on the roadcut was observable mineral sodium-rich amphibole.