Akademik Veri Yönetim Sistemi
74th Geological Congress of Turkey, Ankara, Türkiye, 11 - 15 Nisan 2022, cilt.1, sa.1, ss.1
Here we present an investigation of a basaltic sill formation, which was observed for the first time intercalated in the early-mid Miocene turbiditic sedimentary rocks exposed near the Iskenderun basin (Southern Türkiye). In order to shed light to its origin and age, the calcareous nannoplankton content of paleontological clastic samples systematically obtained from the measured stratigraphic section (Karataş Formation) around Sarımazı village (Ceyhan/Turkey). Belonging to 14 calcareous nannoplankton genera, 40 different species were identified in the samples representing the Langhian-Serravallian-Tortonian (mid-late Miocene) time interval. Considering the stratigraphic distribution of the calcareous nannoplankton species in the section, the age of the sill was evaluated as Tortonian (mid-Miocene). Analysed in situ major element contents (EMPA-Electron microprobe analysis) for minerals (plagioclase, olivine and clinopyroxene) hosted by late Miocene basaltic rocks of the sill shown that these volkanics originated in an intra-plate setting. Geochemical analyses present that examined olivines have Fo (forsterite) compositions between 57.81% and 83.83%. EMPA contents (primarily based on pyroxenes) verified that studied late Miocene volcanism was matched to Pleistocene basaltic rocks of Delihalil-Turunçlu volcanism and was of an intraplate affinity. Accordingly, we suggested that the tectonic environment of late Miocene basaltic sill is similar to those of the extensive Delihalil volcanism located close to the studied region. This may extend back the initiation of the regional basaltic volcanism to middle-upper Miocene, which was previously supposed to be of Pleistocene-Quaternary.