Évolution pression–température des amphibolites de la zone axiale au cours du métamorphisme hercynien des Pyrénées orientales

Thin levels of amphibolites from the Canigou, Albères and Cap de Creus massifs have been studied in order to investigate their pressure and temperature evolution during time. P and T values have been calculated using the amphibole–plagioclase–quartz thermo-barometer. Si, Al, Mg and Fe of zoned amphiboles have been analysed from core to rim by microprobe. By combining the results obtained from several (or different) crystals, P–T–t paths have been determined using the amphibole-plagioclase-quartz equilibriums. In the Canigou Massif, the amphibolites have recorded anti-clockwise P–T–t paths around a peak of metamorphism located at about 650 °C–6.1 kbar, whereas in the Albères Massif, the calculated P–T–t paths of amphibolites near the paragneisses are retrograde only, from 600 °C–5 kbar to 450 °C–2.5 kbar, but one cummingtonite-bearing amphibolite has also recorded an anti-clockwise evolution around 650 °C–4.5 kbar. The retrograde P–T–t paths recorded for amphibolites from the ‘Cap de Creus’ Massif are retrograde only, from 650 °C–6 kbar and 400 °C–1 kbar. To cite this article: C. Triboulet et al., C. R. Geoscience 337 (2005).