Abstract
The Tavşanlı Zone (TZ) is a high-pressure/low-temperature metamorphic belt representing subduction and exhumation between the Sakarya Zone and the Afyon-Bolkardağ Zone in western Anatolia. This paper provides new and precise geological data including whole-rock and mineral chemistry, phengite 40Ar/39Ar ages, zircon laser ablation ICP-MS U-Pb, and apatite (U-Th)/He thermochronological information for a region of the Sivrihisar metamorphic complex that has been less studied than other regions of the TZ. This region comprises Permo-Carboniferous metamorphic units, Eocene granodiorite and microgranodiorite, terrestrial clastics, and Holocene alluvium. The mineral assemblage of the granite-gneiss contains quartz, plagioclase, K-feldspar, microcline, muscovite, and rare biotite and garnet, while the blueschist comprises plagioclase, white mica, biotite, Na-amphibole, and garnet that are considered to represent greenschist and blueschist facies metamorphism, respectively. We estimate the peak metamorphic conditions for schists of the Permo-Carboniferous metamorphics and associated rocks as T = 303-484 °C and P >=10 kbar. This high-pressure event occurred at ca. 83 Ma, indicated by a well-defined 40Ar/39Ar plateau age for phengite. Laser ablation ICP MS U-Pb analyses of euhedral or subeuhedral magmatic zircons from previously unknown microgranodiorite, intruding the metamorphic rocks, yield an Eocene (50 Ma) age. The new results are interpreted to indicate that lithospheric collision and northward subduction beneath the Sakarya Zone occurred between 83 and 50 Ma. Apatite crystals separated from microgranodiorite yield (U-Th)/He ages consistent with cooling of the Tavşanlı Zone to ~65 °C by ~38 Ma.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
