How to resist subduction: evidence for large-scale out-of-sequence thrusting during Eocene collision in western Turkey

Significant along-strike variations have locked large parts of the Alpine s ubduction complex in the Eastern Mediterranean in the Eocene. and defined t he end of high-pressure accretion in western Turkey. Structural analysis re veals that the Anatolide belt in western Turkey formed under greenschist fa cies metamorphic conditions in the Eocene when a high-pressure metamorphic fragment of the Adriatic plate (the Cycladic blueschist unit) was thrust on to the imbricated mid-crustal units of the Anatolian microcontinent (the Me nderes nappes). The contact between the Cycladic blueschist unit and the Me nderes nappes. the Cyclades-Menderes thrust, represents an out-of-sequence ramp which cuts up-section towards the south. The lack of Alpine high-press ure fabrics below the Cyclades-Menderes thrust implies c. 35 km of exhumati on of the Cycladic blueschist prior to its Eocene emplacement on top of the Menderes nappes. Structure and geodynamic evolution of the Anatolide belt are in striking contrast to the neighbouring Aegean and contradict the mode l of a laterally continuous orogenic zone, in which the Anatolide microcont inent is interpreted as an eastern extension of the Adriatic plate.