Investigating the Metamorphic History of the Menderes Massif (Western Turkey) Using Electron Backscatter Diffraction
Abstract
The Menderes Massif in western Turkey has global importance due to its role as the largest zone of active continental extension on Earth. The region is located at the boundary between the Aegean and Anatolian microplates and is considered a type-location for marking a significant transition between contractional and extensional tectonics across the Alpine-Himalayan chain. The Menderes Massif was exhumed via large-scale extension since the Tertiary. Low-angle detachment faults and high-angle normal faults bound the massifs sedimentary basins and separate the Menderes Massif into northern, central, and southern submassifs. Here we report optical petrography and electron backscattered diffraction (EBSD) data from rocks collected along the low-angle Alasehir detachment, which bounds the northern edge of the central massif. We also obtained data from the Kucuk Menderes Graben and its southern boundary (Buyuk Menderes Detachment). Optical petrography and EBSD of all samples in the study quartz and feldspar through abundant subgrain rotation and minor bulging recrystallization, respectively. All samples record prism <a> slip in quartz from subgrain rotation axes, indicating temperatures of deformation from 500-650 °C. From the northern side of the graben, recrystallized quartz grain size piezometry indicate paleostresses increase from 37 MPa to 68 MPa from south to north towards the Alasehir detachment. Samples taken from the floor of the graben record paleostresses of 66 MPa, and sample from the southern end of the graben record consistent 51 MPa as they traverse south towards the Buyuk Menderes Graben. The analysis of petrographic microstructures from these samples combined with EBSD datasets was used to generate petrological P-T-t-d data to match deformation mechanism, paleopiezometry, and kinematics with tectonic models.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMED35A0569K