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oai:gumushane-rdlopen.rawdatalibrary.net:gumushane/161862026-10-23T18:25:57Zopenairecom_gumushane_10000col_gumushane_10001com_gumushane_10007col_gumushane_10171

Post-Variscan autochthonous cover in the eastern Sakarya Zone, Turkey: Evolution of the late Carboniferous back-arc ocean to the Triassic Karakaya OceanDokuz, AbdurrahmanAlçiçek, Mehmet CihatTunçdemir, VahdetKandemir, RaifAydinçakir, Emrelate CarboniferousAutochthonous covereastern Sakarya ZonePaleotethysBack -arc basin migrationGeodynamicsThe processes that caused removal of the upper Carboniferous to Permian sediments in the eastern Sakarya Zone, Turkey, are modeled by using of geochemical data and LA-ICP-MS U-Pb ages from detrital zircons. A felsic provenance and passive margin setting during the deposition of the upper Carboniferous catalcesme sediments are inferred from the geochemistry of sandstones (SiO2 > 85 wt%). Chemical Index of Alteration (CIA) values (75 - 81) indicate warm and humid climatic conditions and tectonic tranquility during deposition. Fifty-three (58%) concordant zircon grains produce a youngest age population in the range of 308.7 +/- 4.4 to 342.1 +/- 6.9 Ma, typical for the Variscan events. The burgundy color and upward-fining in clast size and bed thickness are the most prominent features of the concordantly overlying Hardisi Formation. Geochemistry (SiO2 = 66-81 wt%) and CIA values (58-65) of the clastic rocks point to a subduction-related tectonic setting and increasing rate of erosion in the source area. We highlight that the catalcesme sediments were deposited in a back-arc basin opened to the south of a continental ribbon separated from Gondwana. Approaching of the Paleotethyan mid-ocean ridge to the subduction zone was resulted in flattening in subducting slab, which in turn caused the back-arc basin to migrate into the interior parts of Gondwana and the former back-arc basin to evolve into a lacustrine setting. Increase in the elevation of source areas was resulted in an increase in the rate of physical erosion and trans-portation of burgundy Hardisi clastic sediments into the lacustrine basin.PERGAMON-ELSEVIER SCIENCE LTD2023-06Articlehttps://rdlopen.rawdatalibrary.net/r/gumushane/16186https://doi.org/10.1016/j.jseaes.2023.1056211367-9120enJOURNAL OF ASIAN EARTH SCIENCESinfo:eu-repo/semantics/closedAccessinfo:eu-repo/semantics/articlehttps://gumushane-rdlopen.rawdatalibrary.net/tr/items/gumushane/16186