Missing link on the western Paleotethys configuration: Stratigraphic constraints on the truncated Triassic “Gornjak” sequence (eastern Serbia, Balkan/Carpathian hinterland)

Abstract

There is a major overlap of the two lithospheric-scale early Alpine (post-Variscan) extensional geodynamic drivers which contributed to the crustal thinning of the north Mediterranean margin/south European foreland/ Dinaride-Hellenide-Carpathian/Balkan/Rhodope continental amalgamation. A widespread late Permian-Triassic Alpine extension interacted with the coeval Paleotethyan rollback, producing a number of intraplate and marginal basins, later coalesced to form the Neotethys Vardar Ocean. However, some of these externally-positioned, north-south striking elongated basins (eastern Serbia), were abruptly interrupted by an unreported Triassic event. This event truncated the latest Permian to Lower – Middle Triassic sequence of the Getic unit, best exposed near the Gornjak area (Balkan-Carpathian hinterland, “Carpatho-Balkanides”, western Moesian foreland). At Carpathian-Balkan scale, this rather undocumented geodynamic episode is consistent with the “early Cimmerian” “docking” event (recorded within the Moesian platform, and the North Dobrogea Orogen). Based on the surface/ subsurface geological and available scarce literature data, the truncated Lower- and Middle Triassic sedimentary successions of the “Gornjak basin” (eastern Serbia), provide new constraints on the timing of the Triassic western Paleotethyan closure. The study emphasizes a far-field effect of the Upper Triassic Paleotethyan demise and Cimmerian “docking”, largely obscured by the late Alpine shortening and the formation of the Carpathian/Balkan fold-and-thrust belt.