The Cisuralian of the Southern Alps: Radiometrically Calibrated Continental Successions Key for Refining Lower Permian Palynostratigraphy

The Permian of the Southern Alps (N Italy) represents one of the largest and best-preserved volcanic successions of the upper Cisuralian in Europe, including the Athesian Volcanic District (AVD), the Collio Basin, and the Orobic Alps. The AVD, in particular, provides an exceptionally high-resolution chronostratigraphic framework based on detailed geological mapping and U–Pb zircon geochronology. Continental sedimentary sequences intercalated within volcanic units were deposited during phases of reduced volcanism, typically in alluvial–lacustrine environments and yield abundant and diverse paleobotanical remains. Palynological assemblages from ten stratigraphic sequences belonging to the Monte Luco, Verano, Guncina, and Tregiovo formations have been studied spanning a middle to upper Kungurian age interval. Two palynozones were differentiated: the Vittatina and Protohaploxypinus palynozones. Moreover, the comparative analysis of these assemblages allows refinement of the stratigraphic ranges of key Permian palynological taxa, including Gigantosporites aletoides, Jugasporites delasaucei, Lueckisporites virkkiae, Nuskoisporites dulhuntyi, Taeniaesporites noviaulensis, and Vestigisporites spp. The new AVD records of these taxa, traditionally considered typical of younger (Guadalupian to Lopingian) intervals, have implications for their chronostratigraphical ranges, at least within the southeastern Euramerican phytoprovince. These results highlight the value of the AVD as a radiometrically calibrated reference for Cisuralian continental palynostratigraphy and provide a framework for future interbasinal correlations across the Southern Alps.