U-Pb zircon geochronology of intrusive rocks from an exotic block in the Late Cretaceous – Paleocene Taraklı Flysch (northern Turkey): Constraints on the tectonics of the Intrapontide suture zone. (March 2019)

• Record Type: Journal Article
• Authors: Di Rosa, Maria; Farina, Federico; Marroni, Michele; Pandolfi, Luca; Göncüoğlu, M. Cemal; Ellero, Alessandro; Ottria, Giuseppe
• Is Part Of: Journal of Asian earth sciences. Volume 171(2019)
• Page Start: 277
• Page End: 288
• Publication Date: 2019-03
• Subjects: Permian granitoids -- Slide-block -- Foredeep -- Intrapontide suture -- Taraklı Flysch -- Turkey; Earth sciences -- Asia -- Periodicals; Sciences de la terre -- Asie -- Périodiques; Earth sciences; Asia; Periodicals; 555.05
• DOI: 10.1016/j.jseaes.2018.11.017
• Languages: English
• ISSNs: 1367-9120

Abstract

Graphic abstract: Highlights: Taraklı Flysch sedimented in a foredeep during a continental collision. The top of the Taraklı Flysch shows a "slide-blocks in shaly-matrix" lithofacies. The top of the Taraklı Flysch is characterized by slide blocks of granitoids. Permian age of granitoids is determined by U-Pb geochronology on zircon crystals. The source area of the granitoids is identified in the Istanbul-Zonguldak margin. The geodynamic setting of the Taraklı Flysch is reconstructed. Abstract: In the Boyalı area (northern Anatolia), a thick succession of the Early Maastrichtian - Middle Paleocene Taraklı Flysch crops out. The Taraklı Flysch represents a foredeep sediment deposited during the final stage of collision between the Sakarya and Istanbul-Zonguldak continental margins, that developed as a consequence of the closure of the Intrapontide oceanic basin. The top of the Taraklı Flysch is characterized by a level of slide-block in shaly-matrix lithofacies that can be considered as the result of several fast catastrophic events predating the closure of the basin and its deformation. This level consists of slide-blocks surrounded by monomict pebbly-mudstones and pebbly-sandstones. Among the slide-blocks, the biggest one consists of quartz-monzonites and leucocratic granodiorites of Late Permian age (260.8 ± 2.2 Ma) dated by zircon LA-ICP-MS method. By comparison with the regional data, the source area of these granitoids can be identified in the Istanbul-Zonguldak terrane. This evidence suggests a new picture for the paleogeographic setting of the ultimate stage of the continental collision between the Istanbul-Zonguldak and the Sakarya continental margins. In this scenario the coarse-grained deposits of the Taraklı Flysch are supplied by an orogenic wedge, consisting of oceanic units topped by the Istanbul-Zonguldak terrane. This orogenic wedge represented the north side of the foredeep, while the southern one was represented by the still undeformed Sakarya continental margin.