Processi di anatessi in crosta profonda: Un esempio nella Zona Ivrea-Verbano (Val d'Ossola, Italia Nord-Occidentale).

The Ivrea-Verbano zone, Southern Alps, is a section of lower crust intruded by basic magmas, both later reequilibrated at high P-T conditions. In the Val Fiorina, north of the middle Val d'Ossola, these concordant intrusions are constituted by sills of differentiated basic rock (gabbro, amphibolic pyroxenite and peridotite) that are bounded by very restitic crustal rocks (garnetites) from former felsic granulites. The whole rock major element trends, mineral associations, phase crystalchemistry and patterns of minor and trace elements from these crustal rocks are consistent with anatectic processes. These processes were supposedly generated by the intrusion of basic sills, produced in the surrounding metasediments a restitic portion (garnetites) and a granitic melt, the latter presently recorded in the area by some leucocratic dykes.