Two symmetrically arranged detachment systems delimit the central Menderes metamorphic core complex and define a bivergent continental breakaway zone in the Anatolide belt of western Turkey. Structural analysis and apatite fission-track thermochronology show that a large east-trending syncline within the Alpine nappe stack in the central part of the orogen is related to late Miocene-early Pliocene to recent core-complex formation. The syncline formed as a result of two opposite-facing rolling hinges in the footwalls of each of the two detachments. Back-rotation of the syncline limbs suggests that the detachments rotated from an initial dip of 40؇-60؇ to a currently shallow orientation of 0؇-20؇.

Based on lithostratigraphic comparisons the Menderes Massif has been correlated with the Cycladic Massif, thereby implying that the eastern Mediterranean consists of a narrow pre-Alpine basement belt which is laterally continuous over a long distance and which experienced a similar Alpine orogenic history. Our work indicates that the architecture, the age of basement and the pre-Alpine and Alpine tectonometamorphic history of both massifs differ fundamentally from each other. The Menderes Massif consists of remnants of the Cycladic Massif which overly an exotic unit, the Menderes nappes. Both massifs do not represent lateral continuations which has implications for palaeogeographic reconstructions.

Structural, metamorphic, and geochronologic work shows that the Ampelos/Dilek nappe of the Cycladic blueschist unit in the eastern Aegean constitutes a wedge of high-pressure rocks extruded during early stages of orogeny. The extrusion wedge formed during the incipient collision of the Anatolian microcontinent with Eurasia when subduction and deep underthrusting ceased and the Ampelos/Dilek nappe was thrust southward over the greenschist-facies Menderes nappes along its lower tectonic contact, the Cycladic-Menderes thrust, effectively cutting out a ∼30- to 40-km-thick section of crust. The upper contact of the Ampelos/Dilek extrusion wedge is the top-to-the-NE Selçuk normal shear zone, along which the Ampelos/Dilek nappe was exhumed by ∼30–40 km. Detailed Rb-Sr and 40Ar/39Ar dating of mylonites demonstrates that both shear zones operated between 42 and 32 Ma. There is no evidence for episodic motion during the ∼10 Myr life span of the shear zones, suggesting that both shear zones operated in a steady, nonepisodic fashion. Our data provide supporting evidence that simultaneous thrust-type and normal sense shearing can accomplish the early exhumation of deep-seated rock

Deformation fabrics in Proterozoic/Cambrian granitic rocks of the Þine nappe, and mid-Triassic granites of the Bozdag nappe constrain aspects of the tectonometamorphic evolution of the Menderes nappes of southwest Turkey. Based on intrusive contacts and structural criteria, the Proterozoic/Cambrian granitic rocks of the Þine nappe are subdivided into older orthogneisses and younger metagranites. The deformation history of the granitic rocks documents two major deformation events. An early, pre-Alpine deformation event (D PA ) during amphibolite-facies metamorphism affected only the orthogneisses and produced predominantly top-to-NE shear-sense indicators associated with a NE-trending stretching lineation. The younger metagranites are deformed both by isolated shear zones, and by a major shear zone along the southern boundary of the Þine submassif. We refer to this Alpine deformation event as D A3 . D A3 shear zones are associated with a N-trending stretching lineation, which formed during greenschistfacies metamorphism. Kinematic indicators associated with this stretching lineation reveal a top-to-south sense of shear. The greenschist-facies shear zones cut the amphibolite-facies structures in the orthogneisses. 207 Pb/ 206 Pb dating of magmatic zircons from a metagranite, which crosscuts orthogneiss containing amphibolite-facies top-to-NE shear-sense indicators, shows that D PA occurred before 547.21.0 Ma. Such an age is corroborated by the observation that mid-Triassic granites of the Þine and Bozdag nappes lack D PA structures. The younger, top-to-south fabrics formed most likely as a result of top-to-south Alpine nappe stacking during the collision of the Sakarya continent with Anatolia in the Eocene.

P–T conditions, mineral isograds, the relation of the latter to foliation planes and kinematic indicators are used to elucidate the tectonic nature and evolution of a shear zone in an orogen exhumed from mid‐crustal depths in western Turkey. Furthermore, we discuss whether simple monometamorphic fabrics of rock units from different nappes result from one single orogeny or are related to different orogenies. Metasedimentary rocks from the Çine and Selimiye nappes at the southern rim of the Anatolide belt of western Turkey record different metamorphic evolutions. The Eocene Selimiye shear zone separates both nappes. Metasedimentary rocks from the Çine nappe underneath the Selimiye shear zone record maximum P–T conditions of about 7 kbar and >550 °C. Metasedimentary rocks from the overlying Selimiye nappe have maximum P–T conditions of 4 kbar and c. 525 °C near the base of the nappe. Kinematic indicators in both nappes are related to movement on the Selimiye shear zone and consistently show a top‐S shear sense. Metamorphic grade in the Selimiye nappe decreases structurally upwards as indicated by mineral isograds defining the garnet‐chlorite zone at the base, the chloritoid‐biotite zone and the biotite‐chlorite zone at the top of the nappe. The mineral isograds in the Selimiye nappe run parallel to the regional SR foliation, parallel the Selimiye shear zone and indicate that the Selimiye shear zone formed during this prograde greenschist to lower amphibolite facies metamorphic event but remained active after the peak of metamorphism. 40Ar/39Ar mica ages and the tectonometamorphic relationship with the Eocene Cyclades–Menderes thrust, which occurs above the Selimiye nappe in the study area, suggests an Eocene age of metamorphism in the Selimiye nappe. Metasedimentary rocks of the Çine nappe 20–30 km north of the Selimiye shear zone record maximum P–T conditions of 8–11 kbar and 600–650  °C. An age of about 550 Ma is indicated for amphibolite facies metamorphism and associated top‐N shear in the orthogneiss of the Çine nappe. Our study shows that simple monophase tectonometamorphic fabrics do not always indicate a simple orogenic development of a nappe stack. Preservation in some areas and complete overprinting of those fabrics in other areas apparently occur very heterogeneously.