Early Permian 90° clockwise rotation of the Maures–Este´rel– Corsica–Sardinia block confirmed by new palaeomagnetic data and followed by a Triassic 60° clockwise rotation

Palaeomagnetic investigations of the Corso-Sardinian block and Maures–Este´rel show
that there has been a change in their magnetic orientation during the Late Carboniferous–Early
Permian period (305–280 Ma). This trend is interpreted in terms of a large-scale 908 clockwise
rotation of the southern branch of the Variscan belt that matches the successive change in shortening
directions revealed by structural geology. The evidence is based on existing structural studies of
the fabrics of syntectonically emplaced granitoids partly based on the anisotropy of magnetic susceptibility,
combined with a large database of isotopic ages. The chronological match between the
palaeomagnetic and tectonic datasets is interpreted here as a result of large-scale dextral wrench
movements in the lithosphere between the Gondwana and Laurussia supercontinents. This
wrench deformation is regarded as a sequel to the dextral rotation of the northern branch of the Variscan
belt during 330–315 Ma which terminated in frontal collision with Avalonia. The continuation
of movement in the southern Variscan realm was due to shearing along the southern margin of
the Avalonian block. An additional clockwise rotation is inferred to have taken place during the
Triassic period. The age of this motion remains to be determined.