Kinematics and U-Pb zircon ages of the sole metamorphics of the Marmaris Ophiolite, Lycian Nappes, Southwest Turkey

ABSTRACT

In the eastern Mediterranean, the Lycian Nappes are found in the structurally uppermost position in the Anatolide-Tauride belt related to the closure of the Neotethys. In Western Turkey, the Marmaris Ophiolite with the metamorphic sole occupies the uppermost tectonic position in the Lycian belt. The metamorphic sole is represented by discontinuous tectonic slices composed of amphibolites, phyllites, micashists and quartzo-feldspathic micaschists. Zircons from the micashists and quartzo-feldspathic micaschists display dark cores and rims. The cores yield ages between 229 and 175 Ma, inner rims yield ages between 153 and 143 Ma and the outer rims show a concordia age of 96.7 ± 0.79 Ma. In terms of their Th/U ratios, the cores and inner rims indicate igneous origin, whereas the outer rims indicate accretion during metamorphism. By dating of these zircons, the deposition time for the protolith of micaschists and quartzo-feldspathic micaschists could be constrained as the Early Cretaceous. Present-day orientation of the kinematic data from the sole metamorphics and the uppermost part of the Karabörtlen formation clearly suggest a top-to-the NE sense of shear. By taking into account the 25^º–30^º anticlockwise post-emplacement rotation of Southwest Turkey, it follows that the Lycian Nappes were emplaced eastward onto the Menderes Nappes. This tectonic model disagrees with the previous tectonic models suggesting northward or southward movement of the Lycian Nappes onto Menderes Nappes.

KEYWORDS:

• Metamorphic sole
• kinematic analysis
• U-Pb LA-ICP-MS zircon dating
• Marmaris Ophiolite
• Southwest Turkey

Acknowledgements

Dr. Wolfgang Siebel is greatly thanked for constructive suggestions on interpreting of dating. We thank Dr. Robert Stern for his painstaking editorial handling and helpful comments that clarified the manuscript. Sinan Ünal helped us during field work. Dr. Gültekin Topuz and an anonymous reviewer are acknowledged for their valuable suggestions and comments. We thank Dr. H. Garcia Chavez for suggestions about English of the manuscript. We also thank Funda Surgun, Cihan Demir and Nurcan Altan at Coordination Unit of Scientific Research Projects in Dokuz Eylül University, İzmir.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplementary data can be accessed here.

Additional information

Funding

This study was financially supported by the Scientific and Technological Research Council of Turkey [TÜBİTAK project code: 113Y144].