The Cataldag Plutonic Complex in Western Anatolia: Roles of Different Granites on the Crustal Buildup in Connection With the Core Complex Development


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Kamaci O., Ünal A. , Altunkaynak Ş. , Georgiev S., Billor Z. M.

ACTIVE GLOBAL SEISMOLOGY: NEOTECTONICS AND EARTHQUAKE POTENTIAL OF THE EASTERN MEDITERRANEAN REGION, cilt.225, ss.189-222, 2017 (Diğer Kurumların Hakemli Dergileri) identifier

  • Cilt numarası: 225
  • Basım Tarihi: 2017
  • Dergi Adı: ACTIVE GLOBAL SEISMOLOGY: NEOTECTONICS AND EARTHQUAKE POTENTIAL OF THE EASTERN MEDITERRANEAN REGION
  • Sayfa Sayıları: ss.189-222

Özet

This study documents the geology, structure and age of the Cataldag. Plutonic Complex (CPC), the rock association within the footwall of the Cataldag. detachment fault zone (CDFZ). CPC consists of two contrasting granitic bodies, an older granite-gneiss-migmatite complex (GGMC) and a younger I-type granodioritic body (CG: Cataldag. granodiorite). GGMC is a heterogeneous body consisting of migmatite, gneiss, and two-mica granite, and represents a deep-seated pluton. By contrast, CG 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). Ar-40/Ar-39 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 CG. The CG-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 Kazdag. Massif) as a result of combined effects of thermal weakening and rollback of the Aegean subducted slab during the Oligocene-Early Miocene.