Tectonic evolution of Leros Island (Dodecanese, Greece) and correlations between the Aegean Domain and the Menderes Massif

The history of subduction below the Aegean region and Western Anatolia is hampered by a lack of comprehension of the correlations between the Cyclades and the Menderes Massif. The Dodecanese Archipelago, key for this discussion, has received very little attention so far. This study is focused on the island of Leros where two tectono-metamorphic units can be observed; the upper Marina unit and the lower Temenia unit. The field study, including new field mapping and structural observations, reveals that Temenia unit has been exhumed under Marina unit through a top-to-the-NE ductile shearing followed by a top-to-the- SW brittle deformation cutting the Temenia/Marina contact. The description of metamorphic aragonite and blue amphibole, complemented by RSCM thermometry, reveals that Temenia unit has been buried down to at least 20 km along a cold metamorphic gradient. In terms of lithology and paleogeographic affinities, the cover of Marina unit is similar to the Lycian Nappes that rest on top of the Menderes Massif and belong to the northern margin of the Pelagonian domain. Temenia unit can then be compared to Lower Cycladic Blueschists Nappe, which could in turn be correlated with 30 the cover of the Menderes Massif, which has also recorded a HP–LT metamorphic overprint.