Tracing the protoliths of the garnet amphibolitic and retrogressed eclogitic slices and a conceptual tectonic model for their emplacement onto the Central Menderes Massif, Turkey: New geochemical data and laser ablation-inductively coupled plasma-mass spectrometry U-Pb zircon and rutile ages

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Gursu S., Moller A., Inglis J. D., Göncüoğlu M. C., Hefferan K., Toksoy-Koksal F., ...More

GEOLOGICAL SOCIETY OF AMERICA BULLETIN, vol.135, no.9-10, pp.2486-2509, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 135 Issue: 9-10
  • Publication Date: 2023
  • Doi Number: 10.1130/b36339.1
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Aquatic Science & Fisheries Abstracts (ASFA), Artic & Antarctic Regions, CAB Abstracts, Communication Abstracts, Compendex, Computer & Applied Sciences, Environment Index, Geobase, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.2486-2509
  • Middle East Technical University Affiliated: Yes


The age, emplacement, and metamorphic history of the garnet amphibolitic and retrogressed eclogitic slices in the Menderes Massif (Eastern Aegean) have been a matter of debate since the 1990's. Late Cretaceous garnet amphibolitic and retrogressed eclogitic slices in the Bozdag and Cine nappes show low-angle tectonic contacts with the surrounding Early Cambrian meta-siliciclastics in the Alasehir-Yahyaalci and late Neoproterozoic basement rocks in the Birgi and Tire-Camlica Klippe in the northern Menderes Massif. Lower and upper intercept ages on the discordia diagrams of the garnet amphibolitic slices are 82 +/- 230 Ma and 554 +/- 14 Ma, respectively, in the YahyaalciAlasehir area of the Bozdag Nappe; and 96 +/- 260 Ma and 550 +/- 13 Ma, respectively, in the Camlica-Tire Klippe area of the Cine Nappe. Retrogressed eclogitic slices give dates of 81 +/- 13 Ma lower intercept and 546 +/- 13 Ma upper intercept discordant ages in the Yenisehir-Kiraz area of the Cine Nappe. Lower intercept age of 81 +/- 13 Ma is supported by two spots dated on metamorphic zircons showing positive Eu patterns yielding 86.0 +/- 1.3 Ma concordant age. Zircon U-Pb dating on the oscillatory zoning spots are dated as 537.5 +/- 1.6 Ma (mean square weighted deviation [MSWD] = 1.5, n = 41) for the garnet amphibolic slices in the Yahyaalci-Alasehir area (Bozdag Nappe), 539.0 +/- 1.1 Ma (MSWD = 1.4, n = 56) for the garnet amphibolite slices in the Camlica-Tire Klippe area (Cine Nappe), and 536.6 +/- 2.3 Ma (MSWD = 1.7, n = 32) for the retrogressed eclogitic slices (Cine Nappe). These ages combined with Eu negative anomalies on the dated spots are evaluated as representing their magmatic crystallization ages of the protoliths. Garnet isopleth intersections and pseudosections gave pressure-temperature conditions of 14 kbar and similar to 680 degrees C for the retrogressed eclogites, whereas garnet amphibolites display disequilibrium in whole rock scale. We propose that the age of their protoliths likely correlate with the Cadomian riftrelated Early Cambrian meta-mafic dykes that were subducted beneath the Izmir-Ankara-Erzincan Neotethyan lithosphere during the Late Cretaceous. The new rutile U-Pb age of 30.1 +/- 2.0 Ma supports that the tectonic slices of the Izmir-Ankara oceanic lithosphere and metamorphosed Tauride-Anatolide continental margin were emplaced onto the Menderes Massif to generate the "main Menderes metamorphic terrane" during the latest Paleocene and early Eocene.