Southward roll-back and slab retreat of the subducting African plate has been the cause of extension and magmatism in the Aegean since the Early Miocene. The Hellenic subduction system has shown a progressive southward-migration provoking activity on a series of detachment faults and successive associated exhumation episodes of HP-rocks. Volcanism has been localized during Oligocene–Middle Miocene in central Aegean, and from Pliocene to Recent in the south Aegean. Plutonism, active during Early to Middle Miocene also shows a southward migration through time. Fission-track dating of detrital zircon from exhumed HP-rocks along the volcanic arc and the fore-arc ridge shows at least two zones of successive exhumation episodes of HP-rocks. Zircon fission-track (ZFT) dating from the small exposure of metamorphic basement in Paliochori, on Milos Island, located below the unmetamorphosed Neogene limestones and Pliocene to Recent volcanic rocks, documents an older exhumation episode active at ~16 Ma. In comparison, exhumation of metamorphic rocks on and near Kythera Island was active at ~11 Ma. In the southwestern part of Aegean the exhumation was accompanied by activity on two successive low-angle detachments. We infer that rapid roll-back and slab retreat resulted in the migration of the locus of exhumation of HP-rocks from the Cyclades towards the Peloponnese-Cretan fore-arc ridge of the southwest Aegean during the interval of 16-11 Ma. Fore-arc migration and overall extension of at least 150 km occurred in this interval, with rates up to ~30 mm/yr.
|Number of pages||16|
|Journal||Geochemistry, Mineralogy and Petrology|
|Publication status||Published - 1 Dec 2012|