Original paper

A Late Carboniferous age of the gneiss of Potamos (Kythira Island, Greece) and new considerations on geodynamic interpretations of the Western Hellenides

Seidel, Markus; Zacher, Wolfgang; Schwarz, Winfried H.; Jaeckel, Petra; Reischmann, Thomas

Abstract

Gneiss intercalations occur in schists of the Phyllite-Quartzite unit (Kythira Island, Greece). The gneisses are orthogneisses representing a metamorphosed granitoid or granite. The protolith has an age of 302 ± 12 Ma thus suggesting that the metasediments of the Phyllite-Quartzite unit were originally partly underlain by a Hercynian basement. The former granite was subducted together with sediments of the Phyllite-Quartzite unit and underwent an early Miocene HP-LT metamorphic overprint, dated by 40Ar-39Ar step heating technique of white mica with 19.30 ± 0.44 Ma. The ages from Kythira comply with radiometric data from the Phyllite-Quartzite unit s. str. of neighbouring Peloponnese and Crete. The radiometric data are leading to an improved model of the late Palaeozoic and post-Hercynian development and the much later Miocene Neohellenic subduction.

Keywords

Kythira IslandGreece