The Çataldagğ Plutonic Complex in Western Anatolia: Roles of different granites on the crustal buildup in connection with the core complex development

This study documents the geology, structure and age of the Çataldagğ Plutonic Complex (ÇPC), the rock association within the footwall of the Çataldagğ detachment fault zone (ÇDFZ). ÇPC consists of two contrasting granitic bodies, an older granite-gneiss-migmatite complex (GGMC) and a younger I-type granodioritic body (ÇG: Çataldagğ granodiorite). GGMC is a heterogeneous body consisting of migmatite, gneiss, and two-mica granite, and represents a deep-seated pluton. By contrast, ÇG represents a discordant, shallow level intrusive body. New U-Pb zircon (LA-ICP-MS) and monazite ages of GGMC yielded magmatic ages of 33.8 and 30.1 Ma (Latest Eocene-Early Oligocene). ⁴⁰Ar/³⁹Ar muscovite, biotite, and K-feldspar from the GGMC yielded the deformation age span 21.38 ± 0.05 Ma and 20.81 ± 0.04 Ma, which is also the emplacement age (20.84 ± 0.13 Ma and 21.6 ± 0.04 Ma) of ÇG. The ÇG-GGMC duo represents a core complex, which was exhumed in the Early Miocene as a dome structure in the footwall of a ring-shaped low-angle detachment surface. A number of microscale and mesoscale shear sense indicators display evidence that the rocks underwent a ductile deformation in the earlier stage of the elevation, which was superimposed later by a semibrittle and brittle deformation. They indicate top-to-north and top-to-northeast sense of movement. The exhumation process was partly contemporaneous with the development of the major core complexes of the region (e.g., the Menderes Massif and the Kazdağ Massif) as a result of combined effects of thermal weakening and rollback of the Aegean subducted slab during the Oligocene-Early Miocene.