The Ivrea crustal cross-section (northern Italy and southern Switzerland)

Abstract

The Ivrea crustal section is situated at the internal border of the Alpine arc, south and east of the Insubric Line. A large gravity anomaly and inverted seismic velocities have lead to the model of an exposed crustal section comprising the following units: 1) the Ivrea Zone with peridotites, mafic rocks and paragneisses in the amphibolite and granulite facies (lower crust and basalt intermediate crust); 2) the Strona-Ceneri and Val Colla Zones with granitic gneisses, paragneisses and micaschists in the amphibolite facies (intermediate crust); 3) the Late Paleozoic to Tertiary sedimentary cover of the aforementioned units (upper crust). The crustal section is not strictly continuous, since it is truncated by several, variously aged faults. -Author