Resumen de Oligo-Miocene exhumation of thè Canigou Massif (Pyrénées, France): fission track and (U-Th)/He contribution
O. Maurel, Miguel Bruno Mejías, P. Monié, R. Pik
In the eastern part of the Pyrenean orogen, the extensional tectonics related to the Mediterranean opening were responsible for the reactivation of older structures such as the Têt fault, by normal faulting and concomitant sedimentation in the Conjlent-Cerdagne basin. The minimum onset of exhumation of the Variscan gneiss of Canigou massif is dated at 26-27 Ma using both FT and (U-Th)/He methods, in agreement with other data from the West Mediterranean, but 3-4 Ma older than the first sediments deposited in the Confient basin. The calculated exhumation rate is 0,3±0,06 mm year from mid-Oligocene to mid-Burdigalian; this suggests that denudation was tectonically assisted by the activity of Têt fault. The subsequent evolution is followed by a slower rate of exhumation that accounts for the amount of total exhumation. The exhumation slowed down during the upper Miocene before a last surface uplift pulse during the Messinian time.
