The North Cycladic Detachment System and associated mineralization, Mykonos, Greece: Insights on the evolution of the Aegean domain

Abstract

In the Aegean back‐arc domain, some 30–35 Ma ago, an increase of the rate of slab retreat led to the initiation of post‐orogenic extension, largely accommodated by large‐scale structures such as the North Cycladic Detachment System (NCDS). Although this extension is still active nowadays, an E–W compressional regime developed in the Late Miocene with the propagation of the North Anatolian Fault. On Mykonos island (Cyclades), the NE–SW back‐arc extension is particularly well expressed with the Livada and Mykonos detachments that belong to the NCDS and that are associated with NW–SE barite veins emplaced during the synkinematic cooling of the Mykonos intrusion. This study shows that the formation of the mineralization occurred when the pluton crossed the ductile‐to‐brittle transition during its exhumation below the NCDS at ~11–10 Ma. In addition, the kinematics of mineralized structures evolved with time: (1) most of the displacement was accommodated by the top‐to‐the‐NE Livada and Mykonos detachments accompanied by the formation of mineralized normal faults that were (2) reworked in a strike‐slip regime with an E–W direction of shortening and a persistent NE–SW stretching and (3) a late post‐mineralization E–W compressional stage with a minor reworking of shallow‐dipping faults (locally including the detachments themselves). We interpret this increase of the E–W shortening component recorded during the mineral deposition as a consequence of the initiation of the westward motion of Anatolia from 10 Ma, thus 4 Ma before the propagation of the North Anatolian Fault in the Dardanelles Strait and the localization of the strain on the Aegean Sea margins.

Synextensional Granitoids and Detachment Systems Within Cycladic Metamorphic Core Complexes (Aegean Sea, Greece): Toward a Regional Tectonomagmatic Model

“…(b) Tectonic map of the Mykonos‐Delos‐Rhenia metamorphic core complex and associated flanking detachments. Field‐based measurements of finite strain markers originate from Lucas (), Lecomte et al (), Denèle et al (), and Menant et al (). My = Mykonos magmatic complex.…”

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

“…At the same time, the stress regime in the Cyclades changed rapidly with the development of a distributed strike-slip then compressional deformation [Ring et al, 1999a;Avigad et al, 2001;Menant et al, 2013]. The exact reason for this late Miocene E-W compression recorded in the Cyclades is unclear.…”

“…About 12 Ma ago, the whole Anatolide-Tauride block started to move westward, mostly accommodated by the dextral strike-slip NAF that propagated throughout the Pontides and reached the Dardanelle Strait 6-5 Ma ago (figures 8t-w) [Armijo et al, 1999;Şengör et al, 2005;Melinte-Dobrinescu et al, 2009]. However, as early as the late Miocene, distributed strike-slip then E-W compressive tectonics developed, probably as a result of this westward extrusion notably in western Anatolia along the Izmir-Balıkesir Transfer Zone [Ersoy et al, 2011] and in the Cyclades with the folding and local reactivation of detachments with a reverse movement [Avigad et al, 2001;Menant et al, 2013].…”

“…Following this extensional tectonic regime, distributed strike-slip tectonics then E-W compression developed in the Cyclades in the late Miocene inducing folding and local reactivation of detachment planes as reverse faults (figure 5) [Ring et al, 1999a;Avigad et al, 2001;Menant et al, 2013].…”

Synkinematic skarns and fluid drainage along detachments: The West Cycladic Detachment System on Serifos Island (Cyclades, Greece) and its related mineralization

“…(Spencer and Welty, 1986;Myers et al, 1986;Smith et al, 1991;Beaudouin et al, 1991;Beaudoin and Therrein, 1999;Cashman and Elder, 2002;Maineri et al, 2003;Seidel et al, 2005;Holk and Taylor, 2007;Menant et al, 2013). Studying the interactions between fluid, rocks and deformation is then crucial when addressing such economic mineralized systems.…”