Evolution of Metamorphism in Naxos,Greece

Paper summary:

Naxos lies between the Greek and Turkish mainland and to the north of the Hellenic subduction zone. It exhibits the most complete structural and chronologic record of the Cyclades. The lithologies observed in Naxos are metamorphic complex consist of a variety of schists (serpentinite, quartz, mica-quartz, mica and amphibolite), marbles (mylonitised, non-mylonitised and dolomitic), gneiss, migmatite and igneous intrusions such as granodiorite, pegmatite and aplite. The Pliocene sediments are not observed in the mapping area as it has been completely eroded.
Naxos underwent four stages of deformation, two stages of metamorphism and three generations of folding. High pressure and low-temperature mountain building due to Alpine compressive stress regime (D1) and initiation of North subduction zone induced blueschist metamorphism (M1), isoclinal fold (B1) and open fold (B2). Slab rollback along the Hellenic trench controlled by extensional tectonics in the back-arc area caused rapid North-South extension and crustal thinning (D2) overprinted the M1 by Barrovian low pressure and high-temperature greenschist to locally upper amphibolite facies metamorphism (M2) developing kyanite and sillimanite isograds. M1 and M2 have the same pervasive foliation orientation (S1), but M2 shows lineation of sillimanite and kyanite mineral (L1).
The proposed model of gneissic structural dome involves a combination of buoyancy‐ and isostasy‐driven processes. A regional North-South extension triggered the convergent flow of molten crust at depth and the upwelling of the migmatites within the dome to produce the structural dome. Miocene episodic post-metamorphic arc rotation events produced temporary West-East compression (D3), reactivating and refolding B1 and B2 folds to form B3 folds. B3 folds formed by a maximum compressive stress in E-W direction developed a crenulation lineation, L2 sub-parallel​ to L1 mineral elongations. Granodiorite intruded in the Western part to form contact metamorphism, M3 which cross cut the metamorphic complex and has a stretching lineation of hornblende, L3. Series of thrusts, normal, oblique and strike-slip faults are observed and interpreted to be related to the continued extension in the Aegean region and possible continued slab rollback of the Hellenic trench.