Diachronous uplift and cooling history of the Menderes core complex, western Anatolia (Turkey), based on new Zircon (U-Th)/He ages Zeynep Oner Baran a, ⁎, Yildirim Dilek b , Daniel Stockli c a Department of Geology & Geological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA b Dept. of Geology & Environmental Earth Science, Miami University, Oxford, OH 45056, USA c Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX 78712, USA abstract article info Article history: Received 26 August 2016 Received in revised form 29 November 2016 Accepted 2 December 2016 Available online 05 December 2016 New (U-Th)/He thermochronology data from the syn-extensional granitoids in the central part of the Menderes Massif in western Turkey reveal a minimum slip rate of 12.5 km/Myr along the Alasehir detachment (~14° dip angle) and denudation rates between 1.75 km/Myr and 3.25 km/Myr between 4 Ma and 2 Ma. These values sug- gest relatively fast exhumation of the Central sub-massif, associated with cooling rates between 53 °C/Myr and 128 °C/Myr, which are higher than the estimated footwall cooling rates (60 °C/Myr to 120 °C/Myr) from the Northern sub-massif. Based on the initial crystallization ages of the syn-extensional granitoid intrusions and their exhumation–related cooling ages, our thermochronological findings suggest that the Central sub-massif in Menderes underwent accelerated uplift and faster exhumation in the latest Cenozoic than the Northern and Southern sub-massifs. This latest doming and rapid extension of the Central sub-massif was associated with the asthenospheric upwelling beneath the region and the related Na-alkaline, Kula volcanism. Our results indi- cate that the Menderes Massif has had a diachronous uplift and cooling history during its extensional tectonic evolution in the late Cenozoic. Thermal weakening of the young orogenic crust in western Anatolia via both lith- ospheric and asthenospheric melting episodes and magmatism produced higher than normal geothermal gradi- ents and played a significant role in core complex formation. Published by Elsevier B.V. Keywords: Menderes Massif Alasehir detachment Exhumation Cooling rates (U-Th)/He thermochronology Cenozoic extension 1. Introduction Metamorphic core complexes constitute a significant component of continental extension and provide important, quantitative constraints about the rates of extension and the time, amount and nature of exhu- mation of lower to middle crustal rocks (Coney, 1980; Lister et al., 1984; Lister and Davis, 1989; Jolivet et al., 1994; Lee, 1995; Dilek and Moores, 1999; Foster and John, 1999; Morrison and Anderson, 1998; Miller et al., 1999; Ring et al., 1999; Dilek and Whitney, 2000; Caby et al., 2001; Fayon et al., 2001; Tirel et al., 2008). Most studies of core com- plexes have shown that tectonically driven exhumation plays a stronger role than erosional denudation in their evolution (Davis, 1988; Baldwin et al., 1993; Foster et al., 1994; Scott et al., 1998; Spell et al., 2000; Hejl et al., 2003; Brichau et al., 2010). High-grade metamorphic and deformed rocks in the footwalls of detachment faults in core complexes cool rapidly on their way to the surface via tectonic exhumation, and hence low-temperature thermochronology is a highly effective technique to determine slip rate, and timing of movement and cooling rate in the evolutionary history of detachment faults (Davy et al., 1989; Fitzgerald et al., 1991; Foster et al., 1993; Holm and Dokka, 1993; Richard et al., 1994; John and Howard, 1995; Howard and Foster, 1996; Scott et al., 1998; Hejl et al., 2003; Spell et al., 2000; Wells et al., 2000; Stockli et al., 2001; Carter et al., 2004; Wong and Gans, 2008; Brichau et al., 2010; Lin et al., 2011; Vogl et al., 2012). These data and information are in turn most valuable to better constrain the pattern and kinematics of extensional deformation in highly extended terrains where core com- plexes occur. The Menderes Massif in the Aegean extensional province of western Anatolia is one of the most extensively studied continental extensional domains in the world (Emre and Sözbilir, 1997; Hetzel et al., 1995a,b; Oberhänsli et al., 1998; Lips et al., 1999; Bozkurt and Oberhänsli, 2001; Candan et al., 2001; Gessner et al., 2001a,b; Lips et al., 2001; Okay, 2001; Işık et al., 2003; Rimmelé et al., 2003; Ring et al., 2003; Catlos and Cemen, 2005; Ring and Collins, 2005; Thomson and Ring, 2006; Glodny and Hetzel, 2007; Oner et al., 2010; Çiftçi and Bozkurt, 2010), and includes a series of detachment faults, supradetachment ba- sins, and discrete graben structures in the hinterland of a young (Eo- cene) continental collision zone (Dilek, 2006; Dilek and Altunkaynak, 2007; Oner and Dilek, 2011; and references therein). It is also situated in the upper plate of the Hellenic subduction zone and hence in a back-arc basin tectonic setting (Faccenna et al., 2003; Ring and Layer, 2003; Dilek and Sandvol, 2009; Jolivet and Brunn, 2010). The internal structure, metamorphism, geochronology, and tectonic evolution of Tectonophysics 694 (2017) 181–196 ⁎ Corresponding author. E-mail address: zeynep.baran@sdsmt.edu (Z.O. Baran). http://dx.doi.org/10.1016/j.tecto.2016.12.005 0040-1951/Published by Elsevier B.V. Contents lists available at ScienceDirect Tectonophysics journal homepage: www.elsevier.com/locate/tecto