Metamorphic core complexes of Cordilleran type in the Cyclades, Aegean Sea, Greece

Kinematic reconstructions and magmatic evolution illuminating crustal and mantle dynamics of the eastern Mediterranean region since the late Cretaceous

“…Migmatites associated with S-type granites have also been described in the cores of these metamorphic domes [Jansen and Schuiling, 1976;Lister et al, 1984;Okay and Satır, 2000b;Vanderhaeghe, 2004;Bozkurt et al, 2010;Kruckenberg et al, 2011;Laurent et al, 2015;Beaudoin et al, 2015]. These intrusions are exposed in the footwall of major detachments where they show strong foliation with extensional kinematic indicators as well as cataclastic zones at the contact with the detachments [Faure and Bonneau, 1988;Gessner et al, 2001a;Iglseder et al, 2009;Denèle et al, 2011;Rabillard et al, 2015].…”

“…In the lower Miocene, HT-MP metamorphism (i.e. 5-8.5 kbar, 500-700°C) and associated migmatites also developed in the central Cyclades, such as in the Naxos, Paros, Mykonos and Ikaria islands [Jansen and Schuiling, 1976;Lister et al, 1984;Urai et al, 1990;Keay et al, 2001;Vanderhaeghe, 2004;Duchêne et al, 2006;Kruckenberg et al, 2011;Beaudoin et al, 2015;Laurent et al, 2015]. Exhumation of these rocks as MCCs was accommodated during the Oligocene-Miocene by several ductile-brittle detachment systems (figures 4 and 6) comprising the top-to-the NE North Cycladic Detachment System (NCDS) [Faure et al, 1991;Lee and Lister, 1992;Gautier and Brun, 1994;Mehl et al, 2005Mehl et al, , 2007Brichau et al, 2007Brichau et al, , 2008Jolivet et al, 2010a], the top-to-the N Naxos/Paros Extensional Fault System (NPEFS) [Urai et al, 1990;Gautier et al, 1993;Brichau et al, 2006;Seward et al, 2009;Bargnesi et al, 2013] and the top-to-the SW West Cycladic Detachment System (WCDS) [Grasemann and Petrakakis, 2007;Brichau et al, 2010;Iglseder et al, 2011;Grasemann et al, 2012].…”

“…Located in the center of the Aegean domain, the Cyclades partly expose the buried parts of the Hellenides, exhumed since the Eocene as MCCs in low, medium and/or high temperature environments (figures 4 and 6) [Bonneau, 1984;Lister et al, 1984;Faure and Bonneau, 1988; M A N U S C R I P T…”

“…In the Ios island, a coeval top-to-the S structure called the South Cycladic Shear Zone (SCSZ) is observed at the base of the Cycladic Blueschists unit (figure 6). This structure was interpreted first as an extensional shear zone [Lister et al, 1984] then redefined as a thrust [Huet et al, 2009]. An extrusion model was proposed for the Eocene exhumation of the Cycladic…”

The tectono-metamorphic evolution of a dismembered ophiolite (Tinos, Cyclades, Greece)

“…The low-angle tectonic contact between the two units marks a significant metamorphic gap where a thick crustal section has been omitted. Avigad & Garfunkel (1991), following other authors (Ridley, 1984;Lister, Banga & Feenstra, 1984), argued that the exhumation of the Eocene Blueschist Unit from a depth of more than 50 km occurred by low-angle normal faults. These faults removed the overburden from above the blueschists, leaving thin remnants comprising the Upper Unit.…”