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

Abstract

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 mélange, 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 mélange 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 mélanges, 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 mélange (Avdella mélange). 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. Thematic collection: This article is part of the Ophiolites, melanges and blueschists collection available at: https://www.lyellcollection.org/topic/collections/ophiolites-melanges-and-blueschists