The Usak-Gure basin is a NE-SW-trending extensional basin located in the northern part of the Menderes Massif, in western Anatolia. The Usak-Gure basin contains a Lower to Upper Miocene volcano-sedimentary succession that records the unroofing of the metamorphic rocks of the Menderes Metamorphic Core Complex. We propose a new structural mechanism based on geological mapping and detailed kinematic fault analysis from each of the evolutionary phases. We also propose that north-to NE-dipping low-angle detachment surfaces define the basin boundaries and have identified three stages of deformation throughout the Miocene: the Early Miocene deformation phase (D-2) is characterized by low-angle normal faulting (Simav detachment fault) in the supra-detachment Usak-Gure basin, which marks the initiation of the extensional tectonics during the latest Oligocene; the Middle Miocene deformation phase (D-3) refers to volcano-tectonic activities during accumulation of the Inay Group; the Late Miocene deformation phase (D-4) is related to late Miocene tectonic activity widely responsible for deposition of the Asartepe Formations and uplift of the metamorphic rocks in the Usak basin margin. In addition, we propose that the eastern part of the Menderes Massif was delimited by the 'Usak-Mugla transtensional transfer zone' from Middle Miocene time throughout the eastern part of the Menderes Metamorphic Core Complex.