Enhanced carboniferous magmatism reveals the paleo-tethys dual subduction system: New detrital zircon evidence from western Türkiye

Abstract

The tectonic evolution of the Paleo-Tethys Ocean in Türkiye is controversial, especially the polarity of subduction. This study reports new detrital zircon U-Pb ages and trace-element data from Mesozoic-Cenozoic sandstones of the Tavşanlı Zone and the Taurides Belt, both belonging to or tectonically associated with the Anatolide–Tauride Block (ATB), to assess the extent and significance of Carboniferous magmatism. All sampled sandstones show prominent Carboniferous zircon populations. The pooled Tavşanlı dataset has a dominant peak at ca. 304 Ma and a subordinate Cadomian component at ca. 554 Ma, which displays Pontide-affinity age spectra. Their occurrence within the Cretaceous subduction accretionary complex suggests sediment supply from the adjacent Pontides upper plate to the trench-forearc system or recycling of older Pontide-derived clastic material, rather than direct transport across a wide-open oceanic basin. In contrast, the pooled Taurides dataset is characterized by a ca. 320 Ma peak together with prominent Pan-African and Tonian-Grenvillian components at ca. 641 and 973 Ma, respectively, which predominantly records ATB sources. Zircon trace elements indicate a continental-arc affinity, and εHf(t) compilations reveal systematically different magma source characteristics between Pontides and ATB Carboniferous arcs. Integrated stratigraphic, petrologic, and geochronological evidence supports a dual-subduction model: northward subduction beneath Laurasia coexisting with southward subduction beneath Gondwana.