LATE CRETACEOUS ARC MAGMATISM IN THE SOUTHERN CENTRAL PONTIDES: CONSTRAINTS FOR THE CLOSURE OF THE NORTHERN NEOTETHYAN BRANCHES

Authors

  • Kaan Sayit Department of Geological Engineering, Middle East Technical University, 06800 Ankara, Turkey, Turkey
  • M. Cemal Göncüoğlu Department of Geological Engineering, Middle East Technical University, 06800 Ankara, Turkey, Turkey
  • Alessandro Ellero Istituto di Geoscienze e Georisorse - CNR, Via G. Moruzzi 1, 56124, Pisa, Italy
  • Giuseppe Ottria Dipartimento di Scienze della Terra, Università di Pisa, via S. Maria 53, 56126, Pisa, Italy
  • Chiara Frassi Dipartimento di Scienze della Terra, Università di Pisa, via S. Maria 53, 56126, Pisa, Italy
  • Michele Marroni Dipartimento di Scienze della Terra, Università di Pisa, Via S. Maria 53,56126 Pisa, Italy, e-mail: marroni@dst.unipi.it
  • Luca Pandolfi Dipartimento di Scienze della Terra, Università di Pisa, via S. Maria 53, 56126, Pisa, Italy

DOI:

https://doi.org/10.4454/ofioliti.v47i1.549

Keywords:

andesites, volcanic arc, geodynamics, Neotethys Ocean, Central Pontides, Northern Turkey

Abstract

In the southern Central Pontides in northern Turkey the remnants of two Neotethyan oceanic basins, currently represented by the Intra-Pontide and the Izmir-Ankara-Erzincan sutures, and the interposing continental microplate (i.e., the Sakarya Composite Terrane) are completely dissected by the North Anatolian Shear Zone (NASZ). Within the resulting kilometre-scale, strike-slip fault-bounded blocks, several Late Cretaceous arc-type magmatic units have been detected. In this paper, we present new geochemical data from one of these magmatic units, the Yerkuyu Unit, that forms an ENE-WSW trending 30-km long and 10-km wide lens-shaped body surrounded by the splays of the NASZ. The studied igneous lithologies have a subduction-related magmatic geochemical signature matching with another lozenge-shaped magmatic block of the Tafano Unit. However, the tectono-magmatic characterization indicates that the Tafano Unit magmatism developed within a continental arc tectonic setting, while the volcanic rocks of the Yerkuyu Unit derived from oceanic arc magmatism. This finding indicates that the subducted oceanic lithosphere of the İzmirAnkara-Erzincan branch of the Neotethys Ocean produced oceanic volcanic arcs close to the subduction zone (i.e., the Yerkuyu Unit) and beneath the Sakarya continental microplate (i.e., the Tafano Unit).

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Published

— Updated on 2022-04-08

How to Cite

Sayit, K., Göncüoğlu, M. C. ., Ellero, A., Ottria, G. ., Frassi, C., Marroni, M., & Pandolfi, L. (2022). LATE CRETACEOUS ARC MAGMATISM IN THE SOUTHERN CENTRAL PONTIDES: CONSTRAINTS FOR THE CLOSURE OF THE NORTHERN NEOTETHYAN BRANCHES. Ofioliti, 47(1). https://doi.org/10.4454/ofioliti.v47i1.549