The oldest rocks in Corsica are found in the Argentella Massif, which stretches along the coast southwest of Calvi. These rocks are Neoproterozoic to early Paleozoic in age and therefore witness the pre-Variscan history.
We visited some of these rocks at roadcuts just south of the Bay of Crovani, close to the settlement of Argentella. There, we found a weathered succession interpreted as metagraywackes that consists of laminated, fine-grained metasediments with some quartz-rich layers. The metamorphic grade probably did not exceed the lower greenschist facies. These metasediments were dated with detrital zircon to between 2.6 Ga to 515 Ma.