OICC Press Iranian Journal of Earth Sciences 2228-785X 16 4 2024 11 04 In situ Rb-Sr dating of K-bearing minerals in the Gonen granitoid from the western Sakarya Zone, NW Anatolia 1 9 10.57647/j.ijes.2024.1604.19 EN Firat Sengun Department of Mining and Mineral Extraction, Can Vocational College, Canakkale Onsekiz Mart University, Can- Canakkale, Turkey AND 2. Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden https://orcid.org/0000-0002-7323-9659 Journal Article 2024 11 04 Granitoids with ages ranging from Paleozoic to Tertiary are widely distributed in the westernSakarya Zone. The Gonen granitoid is one of these Paleozoic (Early Carboniferous) granitoidsand exposed on the western part of the Sakarya Zone in NW Anatolia. The Gonen granitoid isunconformably overlain by the Jurassic Bayırkoy Formation consisting of conglomerate, sandstone,siltstone, and claystone intercalation. Medium to coarse-grained, yellowish brown-colored Gonengranitoid chiefly made up of K-feldspar, plagioclase, muscovite, quartz, and biotite. In thispaper, it is presented in situ Rb-Sr isochron ages for the Gonen granitoid in the western SakaryaZone. The isochron derived from muscovite and plagiocalse minerals occurring in the granitoidyielded 299.3 ± 3.4 Ma (Late Carboniferous), which is interpreted as the emplacement age ofthe Gonen granitoid. This study also testifies that radiometric in situ Rb-Sr dating can be appliedto resolve absolute dating of magmatic complexes. According to the initial 87Sr/86Sr ratio, themagma producing the Gonen granitoid was derived from the enriched subcontinental lithosphericmantle forming the ancient crust. The Carboniferous magmatic event can be attributed to thenorthward subduction of the Palae-Tethys oceanic crust along the southern margin of Laurasia inthe Early-Late Carboniferous.