The Petrology and Geochemistry of the Ortakoy Area, Central Turkey

Kocak, Kerim (1993) The Petrology and Geochemistry of the Ortakoy Area, Central Turkey. PhD thesis, University of Glasgow.

Abstract

The Middle Anatolia Massif is one of the largest igneous and metamorphic complexes in Turkey. The western part of the massif is the subject of the present study. The main purposes of the work are to map the different igneous and metamorphic rocks; to identify their mineralogical, petrographical and geochemical characteristics and by considering their relationships to each other, determine the metamorphic, magmatic and geological evolution of the Ortakoy area. The geological map of the Ortakoy area (Appendix-Ia) shows that the oldest identified rocks are the Seksenusagi Formation of Silurian- Devonian age and the conformably overlying Gobektepe Formation of Upper Palaeozoic age. The Ekecekdagi gabbro comprises hornblende-gabbro and minor banded gabbro and may have been emplaced onto the metamorphic rocks as an allochthonous unit or intruded into the metasediments before the intrusion of the Ortakoy pluton. The metasediments were intruded and hornfelsed by the voluminous Upper Cretaceous - Paleocene Ortakoy pluton containing hornblendite, hornblende diorite, biotite-hornblende granitoid, microgranite and quartz- alkali syenite. The massif is overlain by the Pecenek Formation of Pliocene age composed of rhyolitic tuff; clay and sand with some gravels; and lacustrine limestone. Colluvium and alluvium are the youngest formations in the area. The Ortakoy part of the Middle Anatolia Massif underwent four phases of deformation: D1 during the formation of the metamorphic rock fabric, D2 which produced folds varying from isoclinal to tight while D3 folds have open limbs and developed in approximately an E-W direction. D4 folds are usually open with steep axial planes and plunge roughly towards the S-E. The massif was then uplifted inducing the development of the WSW-ENE dominated joint sets in the Ekecekdagi gabbro, diorite and granitoid and the formation of WNW-ESE faults. During or after D1 deformation, the Ortakoy metasediments underwent a single episode of regional metamorphism corresponding to the upper amphibolite facies conditions (second sillimanite grade), which is confirmed by geothermometer studies from the different metamorphic assemblages which yield between 608-761

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: B E Leake
• Keywords: Geology, Geochemistry, Petrology
• Date of Award: 1993
• Depositing User: Enlighten Team
• Unique ID: glathesis:1993-76289
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 Dec 2019 09:15
• Last Modified: 19 Dec 2019 09:15
• URI: https://theses.gla.ac.uk/id/eprint/76289