The role of the pre-Alpine polycrystalline basement in the paleogeographic configuration of multiple Neotethyan oceanic basins

Darko Spahić,Tivadar Gaudenyi

doi:10.5474/geologija.2021.008

Abstract

AbstractThe study provides a deeper understanding of the early Mesozoic paleogeogeographic spatial-temporal relationship by studying the two Adria-Europe intervening basement blocks. The Drina-Ivanjica and Pelagonian crustal fragments play important role in the internal early Alpine oceanic constitution further controlling the late Jurassic emplacement of Tethyan Dinaric-Hellenic ophiolites. The proposed paleogeographic reassessment is driven by the new paleocontinental inheritance data associated with the Variscan – pre-Variscan basement terranes. The recently published data suggest an Avalonian-type inheritance of the Pelagonian basement block which indicates a different pre-Variscan plate-tectonic journey, including separate spatial arrangement during Variscan amalgamation. In turn, Cadomian-type basement inheritance has been documented within the sliced Adria microplate. Thus, the Avalonian inheritance place the Pelagonian block away from the Apulia/Adria (Dinarides). In the investigated context of Paleozoic-Mesozoic paleogeographic transition, the Pelagonian block may represent a segment of the Cimmerian ribbon continent or southernmost segment of the Variscan Europe. With regards the nearby Adria microplate, a Triassic-Jurassic oceanic opening led to the decoupling (spreading away from the main Adria microplate) of the Drina-Ivanjica block. The rifting is in line with the simultaneous yet opposite or westward-directed drift of the Pelagonides. The breakup of south European Variscan configuration eventually result in the spatial alignment of the two basement fragments referred to as the “Drina–Pelagonide continental splinter”. By linking the paleogeographic pre-Jurassic–Jurassic relationship between these continental units, the two landlocked Neotethyan Vardar s.l. basins are extrapolated, “Dinaric Tethys” / Inner Dinaric-(Mirdita-Pindos) and the main Vardar Ocean (Western Vardar Zone).

Highlights

The intriguing lithospheric elements of the Jurassic-earliest Cretaceous paleoceanography in the area of Western Balkan countries (Fig. 1a) underwent final suturing and collisional thrust stacking during the late Mesozoic - Paleogene (e.g., Picha, 2002; Csontos & Vörös, 2004; Schmid et al, 2008; Xypolias et al, 2008; Robertson, 2012; Jolivet et al, 2016; Fig. 1b, c)
In the investigated context of Paleozoic-Mesozoic paleogeographic transition, the Pelagonian block may represent a segment of the Cimmerian ribbon continent or southernmost segment of the Variscan Europe
The breakup of south European Variscan configuration eventually result in the spatial alignment of the two basement fragments referred to as the “Drina–Pelagonide continental splinter”

Summary

Introduction

The intriguing lithospheric elements of the Jurassic-earliest Cretaceous paleoceanography in the area of Western Balkan countries (Fig. 1a) underwent final suturing and collisional thrust stacking during the late Mesozoic - Paleogene (e.g., Picha, 2002; Csontos & Vörös, 2004; Schmid et al, 2008; Xypolias et al, 2008; Robertson, 2012; Jolivet et al, 2016; Fig. 1b, c). Depending of the chosen paleogeographic model (sensu Bernoulli & Laubcher, 1972; adopted by Schmid et al, 2008 among many others or ‘multiple oceans model’, see Spahić & Gaudenyi, 2020, for a discussion; Fig. 3a), ophiolites of similar age are distributed on both sides of the continental splinter: westwards of the intervening the Drina-Ivanjica block and spreading across the Vardar Zone s.s. and the Albanides-Hellenides (Fig. 1c; see Fig. 1 of Faul et al, 2014).

Results

Conclusion