Menderes Masifi’nin soğuma tarihçesi: Ar-Ar Mika yaşlarının önemi

2018-04-23
Menderes Masif is a regional, crustal-scale elogated metamorphic culmination with its long axis trending in NE−SW direction; it forms the most important geological unit in Western Anatolia. The Massif is tectonically overlain by İzmir-Ankara-Erzincan suture zone in the north and Lycian Nappes in the south. It is divided into northern (Gördes), central (Ödemiş-Kiraz) and southern (Çine) submassifs by the Gediz and Büyük Menderes grabens. The massif comprises (1) orthogneisses (they are deformed and metamorphosed Precambrian granites, traditionally known as core augen gneisses) and (2) structurally overlying Palaeozoic schists and Mesozoic marbles (cover metasediments). It has acquired its massif character during regional Barrovian-type metamorphism (Eocene? main Menderes metamorphism) that reached upper amphibolite-greenschist facies conditions. In the following period, the massif has been deformed first ductiley, then brittley, and exhumed in the footwall of low-angle normal faults (detachment faults) and/or extensional shear zones. Supra-detachment basins in the immediate hanging-wall of the detachment faults formed the site of Neogene sedimentation. A detailed and systematic geochronologic campaign (Ar-Ar analyses on mica) has been carried out to determine timing of different deformation phases and exhumation of the massif, and the age of extensional tectonics in western Anatolia. New mica ages from nine different areas throughout the Menderes Massif (Simav, Demirci-Borlu, Gördes, Alaşehir, Ödemiş, Kiraz, Aydın, Çine and Yatağan) can be grouped as Paleocene−Eocene, late Early Oligocene−late Oligocene and Early Miocene. The new ages date the timing of main Menderes metamorphism and cooling of the Menderes Massif. They further suggest that different parts of the massif exhumed at different times and that the sub-massifs in particular have experienced different cooling histories and therefore are related to different tectonic processes.
Citation Formats
E. Bozkurt, “Menderes Masifi’nin soğuma tarihçesi: Ar-Ar Mika yaşlarının önemi,” Ankara, Türkiye, 2018, p. 105, Accessed: 00, 2021. [Online]. Available: https://www.jmo.org.tr/etkinlikler/kurultay/etkinlik_metin.php?etkinlikkod=120&metin_kod=755.