Abstract: The Devonian metasandstones from allocthonous Bolkardağı Unit outcropping in Central (BozkırKonya, İsalı formation Gerez member) and Eastern (Kangal-Sivas, Kangal formation Bakırtepemember) Taurides mainly include quartz (monocrystalline and polycrystalline), feldspar (microclineand plagioclase), phyllosilicate (illite, chlorite, C-V, C-S and dickite) and rock fragments (phyllite andquartzite). Polycrystalline quartz, microcline and phyllitic rock fragments found as higher amounts inthe Bakırtepe member, but plagioclase in the Gerez member. The metasandstones are represented bya composition of quartz arenite in the Gerez member, whereas of subarkose in the Bakırtepe member.Devonian metasandstones have differences such as lithologic (dominance of sand-size siliciclastic rocks)and mineralogic (more feldspar and quartz, appearance of 1M illites, different phyllosilicate assemblages)with respect to overlying and underlying units with same age. Metasandstones were characterized by highcontents of SiO2, Al2O3, Fe2O3 and K2O, and Bakırtepe member is rich in K2O but poor in CaO ana Na2Oin comparison with those of the Gerez member depending on feldspar types. Bakırtepe and Gerez membersare separated from one another and fed largerly from both sedimentary and magmatic sources accordingto the ratios of chondrite-normalized trace elements. As a conclusion; The members of Bolkardağı Unithave the same age and similar stratigraphic setting and lithologies, hovewer some important differenceswith respect to their sources, sedimentations and diagenetic/metamorphic histories. These differenceswere evaluated as sudden changes in provence through transgression related to Variscan orogeny peculiarto northern units of Taurides rather than continuous sedimentation.