New stratigraphic and palaeontological data from carbonates related to the Vourinos-Pindos ophiolite emplacement: implications for the provenance of the ophiolites (Hellenides)

Microfacies analysis and conodont dating on carbonates associated with the Vourinos-Pindos ophiolite emplacement on the Pelagonian unit in northern Greece, combined with structural analysis, enhance our understanding of the palaeogeography and geotectonic evolution of the Hellenides. We focus on a dismembered Triassic Hallstatt Limestone succession incorporated as blocks in the Middle-Late Jurassic Avdella ophiolitic melange, which is identical to a Triassic succession in the western Pindos (Hallstatt-Pindos succession). Initially, the Hallstatt-Pindos succession was deposited on the outer shelf along the eastern Pelagonian margin and later incorporated into the melange during west-directed obduction processes. During the Middle to early Late Jurassic, ophiolites were obducted on the eastern Pelagonian margin, resulting in a nappe stack in front of the ophiolites in the lower plate position. Newly formed trench-like basins in front of the advancing nappe stack became filled with sedimentary melanges, consisting of ophiolitic material mixed with blocks from the Hallstatt-Pindos succession, deposited in an outer shelf position. Subsequently, the Pindos ophiolites overthrust their foreland basin, forming a typical ophiolitic melange (Avdella melange). Consequently, the Triassic-Middle Jurassic Hallstatt-Pindos succession represents a far-travelled Middle-Late Jurassic nappe derived from east of the Pelagonian unit, which was bulldozed westward in front of the west-directed obducting Neotethys ophiolites.