Original paper

Stratigraphy of the Afyon Zone around Emet (Kütahya, NW Anatolia) and geochemical characteristics of the Triassic volcanism along the northern Menderes Massif

Akay, Erhan; Işintek, Ismail; Erdoğan, Burhan; Hasözbek, Altuğ

Abstract

During the Alpine orogeny, the northern margin of the Tauride-Anatolide Block was deeply buried below the Sakarya continent and subjected to high pressure/low temperature metamorphism. Along this suture zone Tavşanli Zone, Afyon Zone, Bornova Flysch Zone and opholitic mélange nappes form the different tectono-stratigraphic units. The Afyon Zone, in its western part, consists of a slightly deformed and metamorphosed Mesozoic platform succession with abundant fossil remains. The lower part of this succession is represented by the İkibaşli Formation which is dominated by the metadetrital units consisting of rhyolitic to basaltic volcanic intervals and large limestone blocks. A platform-type carbonate sequence (Budağan limestone) forms the upper part of the Afyon Zone. From the İkibaşli Formation and the Budağan limestone unit, a Late Triassic to Malm fossil assemblage was identified constraining the depositional age of the platform carbonates and the age of rhyolitic volcanism accompanying the deposition. Geochemical characteristics of the rhyolites indicate a continental crust origin of the magma. The depositional site of the İkibaşli Formation was a tectonically active extensional basin in which rhyolitic and basaltic volcanic activity occurred. This extension along the northern Menderes Massif coincides with the spreading of a branch of the Neotethyan ocean in NW Anatolia. The age and facies characteristics of the Mesozoic carbonate succession of the Afyon Zone resemble those described from various parts of the Tauride-Anatolide Block indicating that they once belonged to the same large platform.

Keywords

afyon zoneİkibaŞli formationbudaĞan limestonemetarhyolitegeochemistrypaleontologynw anatolia