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The Norian magmatic rocks of Jabuka, Brusnik and Vis Islands (Croatia) and their bearing on the evolution of Triassic magmatism in the Northern Mediterranean. The magmatic rocks from Jabuka, Brusnik, Vis Islands and the submerged Brusnik plateau have been investigated to define their age and genetic affinity, identifying their role in the geodynamics of the Adria Plate. The plutonic and lava flow samples have been characterized for their petrography, mineral chemistry, whole rock major and trace elements, and Sr and Nd isotopic compositions. The two samples with the freshest plagioclase crystals have been selected for 40Ar/39Ar analysis, which gave ages of 221.5 ± 2.5 Ma (Brusnik) and 227 ± 5 Ma (Jabuka), similar to those of the Triassic magmatism from the northern part of the Adria Plate and neighbouring territories. Geochemical and isotopic data suggest that the magmatism dominantly sourced from spinel peridotites variously metasomatized during pre-Mesozoic subduction events. Furthermore, the investigated rocks evidence interactions of the magmas with Mid-Late Triassic evaporites. The comparison with other coeval magmatic occurrences from the Adria Plate and its edges shows that the subduction signature of the Triassic within-plate magmatism is mainly related to the evolution of the upper mantle of the Adria Plate. [ABSTRACT FROM AUTHOR]

The Veneto Volcanic Province (VVP; NE Italy) is an intraplate magmatic area whose activity occurred intermittently in the Cenozoic, generating five districts (Val d'Adige, Lessini Mts., Marostica Hills, Berici Hills, and Euganean Hills). This intraplate magmatism was concomitant to the collision of the European plate and Adria microplate and the orogenesis of the neighboring Alpine belt. Different geodynamic models suggested relationships between VVP and the coexisting subduction processes. To give new insights on this on-going debate, this work provides new petrographic and geochemical data, including Sr-Nd-Pb isotopic and 40Ar/39Ar and K Ar geochronological analyses for lavas sampled in the Lessini Mts. and Val d'Adige, which are the oldest VVP magmatic districts, as well as Marostica Hills and Berici Hills, which are the least investigated districts. The trace element distribution indicates that VVP melts were variously affected by metasomatic enrichments stabilized as phlogopite and/or amphibole. The Sr-Nd-Pb isotope ratios conform to the dominant features of sub-lithospheric mantle components widespread at regional scale throughout the whole European and Mediterranean area. Within this framework, the geochronological data indicate that the oldest magmatic episodes occurred in the Eocene (45–42 Ma) in the Lessini Mts. and Val d'Adige, simultaneously with the orogenic magmatism of Adamello intrusive complex along the Giudicarie Fault, a portion of the Periadriatic lineament which is an important Alpine suture. In our geodynamic reconstruction we propose that the Giudicarie Fault is the superficial expression of a slab tear, responsible for the uprising of an asthenospheric poloidal mantle flow, which induced both the Adamello and VVP magmatism. Subsequently, VVP activity migrated eastwards following the general mantle flow as indicated by minor volcanic pulses in the Euganean and Marostica Hills during Oligocene and Miocene. • VVP intraplate magmatism occurred in the South Alpine foreland during Cenozoic. • The mantle source is a garnet-peridotite metasomatized by carbonatitic fluids. • The isotopic ratios of VVP conform to the European Asthenospheric Reservoir signature. • VVP magmatism climax was in the Eocene as the orogenic magmatism along the Alps. • VVP magmatism was induced by a poloidal mantle flow passing through a slab tear. [ABSTRACT FROM AUTHOR]