The new age data and pre-Paleogene stratigraphy of the Kırşehir Massif, Central Anatolia

Kırşehir Masifi’nin Paleojen öncesi stratigrafisi ve yaş bulguları, Orta Anadolu

Authors

Metin BEYAZPİRİNÇ, Ali Ekber AKÇAY, Mustafa Kemal ÖZKAN, Meftun Kerem SÖNMEZ, Mustafa DÖNMEZ

Keywords

Kırşehir Masifi, Çiçekdağı napı, Orta Anadolu plütonik kayaları, stratigrafi

Abstract

The metamorphics belonging to the Kırşehir Massif, which form the pre-Paleogene basement units in Central Anatolia around Kırşehir, are formed from bottom to top by conformable and transitional Late Devonian Kalkanlıdağ, Carboniferous-Early Permian Kervansaray and Late Permian Bozçaldağ formations and by the unconformably overlying Triassic Demirtepe and Jurassic- Cretaceous Saytepe formations. The sedimentation age of 237 Ma were obtained from the clastic zircons in the quartzites of the Demirtepe formation by the U/Pb method, and the metamorphism age ranges from 94.5 Ma and 83.7±3.3 Ma from the metabasites from the Whole Rock by the 40Ar/39Ar method. The Kasımağa and Sırataşlar formations within the Çiçekdağı Nappe belonging to the northern branch of Neotethys, which were tectonically emplaced over these units and the Turonian- Santonian Kargınkızıközü formation, which were the product of ensimatic island arc magmatism, were distinguished. The metamorphics and the Central Anatolian plutonic rocks, which cut the overlying ophiolitic rocks, were differentiated according to their composition, origin and age, and ranges from 71.9±1.7 Ma from the Baranadağ pluton; ranges from 84.0±1.9 Ma and 71.9±7.2 Ma from the Çayağzı pluton; ranges from 69.1±1.2 Ma by the40Ar/39Ar method, and 65.3±1.1 Ma were obtained from the Buzlukdağı pluton by the U/Pb method. The age ranges from 79.1±1.2-68.2±1.2 Ma and 74.5 Ma were obtained from the whole rock by 40Ar/39Ar method from trachyandesites belonging to the Kötüdağ volcanics, which are surface-semi-depth rocks of granite, monzonite and syenite composition plutonic rocks. The cover units overlie all these units with an angular unconformity. https://doi.org/10.19111/bulletinofmre.930051

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