Systematics and biostratigraphy of Oligocene (Rupelian-Early Chattian) foraminifera from lagoonal-very shallow water limestone in the eastern Sivas Basin (central Turkey)

Abstract

The aim of the present work is to describe the Oligocene (Rupelian-early Chattian) shallow water larger foraminifera from central Turkey (Sivas Basin). Among them is a new miliolid genus, Sivasina n. gen. SIREL & OZGEN-ERDEM (type species Sivasina egribucakensis n. gen. n. sp. SIREL & OZGEN-ERDEM), which occurs in the Egribucak, Bakimli, Tuzlagozu and Caygoren sections (E of Sivas). One new Rupelian-early Chattian lagoonal very shallow water peneroplid species Peneroplis flabelliformis n. sp. SIREL & OZGEN-ERDEM from the Egribucak, Tuzlagozu and Caygoren sections and Rupelian lagoonal two new peneroplid species Coscinospira sivasensis n. sp. SIREL & OZGEN-ERDEM, Coscinospira elongata n. sp. SIREL & OZGEN-ERDEM from the Egribucak section (E of Sivas), two new Rupelian very shallow water alveolinid species Praebullalveolina oligocenica n. sp. SIREL & OZGEN-ERDEM and Praebullalveolina minuta n. sp. SIREL & OZGEN-ERDEM from the Bakimli section are described and figured. Furthermore, details on several already known Oligocene species are given (soritids: Praearchaias diyarbakirensis SIREL, Praearchaias minimus SIREL, Archaias kirkukensis HENSON, Archaias asmaricus SMOUT & EAMES; austrotrillinids: Austrotrillina brunni MARIE). In addition, the biostratigraphy of four studied sections is discussed.