The Athesian Volcanic Group (AG) constitutes a major part of the Permian magmatism in the central-eastern Southern Alps. We applied a volcanic stratigraphy model in order to constrain the volcano-tectonic evolution of the investigated area, which represents the northern sector of a caldera margin. In-situ zircon geochronology was also obtained by combined methods (i.e. LA ICP-MS and SHRIMP U/Pb dating) on volcanic, plutonic and metamorphic rocks. The volcano-tectonic collapse involved the rising of a huge dome, which uplifted the central portion of the just-filled caldera with simultaneous collapse of some sectors. The volcanic succession of the north-western sector of the AG is comprised between 279-274 Ma which is about half the time interval (i.e.12-10 Ma) determined for the area immediately to the south. The Ivigna pluton is confirmed to be coeval (i.e. 293.3 \ub1 1.5 Ma) to the Monte Croce pluton (285.4 \ub1 1.6 Ma and 284.3 \ub1 0.7 Ma; cf. Marocchi et al. 2008). Related rhyodacitic dykes (276 \ub1 1 Ma) are also connected to the Permian magmatism.
The age of the protolith of the acid meta-volcanites from the South-Alpine metamorphic basement is constrained by SHRIMP U/Pb geochronology as Ordovician (472 \ub1 4 Ma), with possibly even older (Proterozoic) sedimentary protoliths.
Finally, the radiometric ages confirm an Alpine age (i.e. 34.0 \ub1 1.0 and 28.6 \ub1 1.5) for the tonalitic lamellae intruded along the Periadriatric Line
