The Monte Filau orthogneisses show peculiar metamorphic features. They are probably "Caledonian" granites of anatectic-crustal origin which, before being intruded by the late Variscan granites, underwent two different metamorphic events. The older event caused their alteration into gneisses, with crystallization of andalusite, sillimanite and garnet, and the appearance of pockets of melts, in sites of suitable composition (T>650°C and P 3.5-4.8 Kb).The younger event had mainly cataclastic-mylonitic effects, with recrystallization in the Qtz-Ab-Ep-Chl subfacies. Local contact effects by the late Variscan granites concluded the metamorphic history of the M. Filau orthogneisses.
The gneisses of Monte Filau (Capo Spartivento, SW Sardinia): Petrographic and chemical features.
MAZZOLI, CLAUDIO;VISONA', DARIO
1992
Abstract
The Monte Filau orthogneisses show peculiar metamorphic features. They are probably "Caledonian" granites of anatectic-crustal origin which, before being intruded by the late Variscan granites, underwent two different metamorphic events. The older event caused their alteration into gneisses, with crystallization of andalusite, sillimanite and garnet, and the appearance of pockets of melts, in sites of suitable composition (T>650°C and P 3.5-4.8 Kb).The younger event had mainly cataclastic-mylonitic effects, with recrystallization in the Qtz-Ab-Ep-Chl subfacies. Local contact effects by the late Variscan granites concluded the metamorphic history of the M. Filau orthogneisses.
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