40Ar-39Ar ages of biotites from Corsica and arguments for Permian age of alkaline granitic intrusion

The Western part of Corsica is underlain by Variscan calcalkaline granites which intrude the pre-Variscan basement. These granites and their basement are also intruded by Permian hyperalkaline granites. Overprinted biotites of the basement and the calcalkaline granites show only one plateau age at about 250 m.y., except for a sample of calcalkaline granite from the Cargèse region which has a high temperature plateau age of 330 m.y. related to the emplacement and a low temperature plateau age of 230 m.y. Plateau ages around 250 m.y. due to the intrusion of hyperalkaline granites whose biotites give plateau ages between 250 and 280 m.y. reflect this important thermal event.