100 Million years of tectonic evolution along the Bitlis-Pütürge Suture

The Bitlis-Pütürge Suture between Arabia and Eurasia records protracted Neotethys subduction, culminating in continental collision and the construction of the Southeast Anatolian collisional orogen and associated orogenic plateau. Here, we integrate detrital zircon, rutile, and apatite U-Pb geochronology with zircon Hf isotope analysis of Upper Miocene siliciclastic sediments from DSDP Sites 375/376 and ODP Site 968 in the northern Eastern Mediterranean to explore the offshore archive of detritus eroded from the Bitlis-Pütürge Suture and to reconstruct the tectono-magmatic evolution of Arabia-Eurasia convergence. Detrital age spectra are dominated by Late Cretaceous, Eocene, and Miocene populations and closely resemble those of coeval sediments in southern Anatolia and northern Cyprus, indicating a dominant source in the Southeast Anatolian Orogenic Belt and defining a regionally coherent sediment-routing system established during Arabia-Eurasia collision. Integration of the detrital record with published datasets from eastern Anatolia delineates four stages of convergence: (1) incipient convergence (∼105–90 Ma) marked by subduction initiation and juvenile arc magmatism; (2) peak subduction-accretion (∼90–70 Ma) characterized by evolved arc magmatism, high-grade metamorphism, slab rollback-driven upper-plate extension, rapid exhumation, and large-scale ophiolite obduction; (3) late subduction-extension (∼55–45 Ma) involving renewed subduction and rollback, juvenile back-arc magmatism, high-grade metamorphism, and rapid exhumation; and (4) orogenic climax (∼25–5 Ma) associated with continental collision, slab break-off and/or lithospheric delamination, syn- to post-collisional magmatism, orogen growth, plateau uplift, and enhanced sediment flux into the Eastern Mediterranean. Zircon Hf isotopes indicate long-term reworking of Cadomian crust with variable mantle input during Neotethys convergence. A marked increase in juvenile signatures after ∼13 Ma suggests enhanced mantle input and subcrustal processes contributing to Middle-Late Miocene uplift of the Eastern Anatolian Plateau. Collectively, the data define a ∼100 Ma-long orogenic cycle in the Neotethys and establish a refined tectonic framework for the western Arabia-Eurasia convergence system within the broader Alpine-Zagros-Himalaya orogenic realm.