Malatya havzasındaki sığ denizel sedimanların eosen (orta-geç eosen) bentik foraminifer tanımlaması ve biyostratigrafisi

Abstract

Calismada, 26 cinse ait 50 bentik foraminifer turu tayin edilmis olup bunlardan biri yeni cins (Praecalcarina tohmaensis) ikisi Nummulites cinsine ait yeni turdur (N.sireli, N.acari). Nummulites cinsine ait uc, Alveolina cinsine ait bes tur ise acik adlama ile tanimlanmistir.Olculu stratigrafik kesitlerde tanimlanan bentik foraminifer toplulugu dikkate alinarak ortamsal yorumlar yapilmistir. Buna gore, stratigrafik kesitlerde, gec Lutesiyen (SBZ 16) birimlerinde Nummulites,  Assilina ve Discocyclina’larin bol oldugu,  Bartoniyen’de (SBZ 17-18) Alveolina ve Nummulites’lerin, stratigrafik kesitlerin ust bolumlerinde Alveolina ‘larin, en ust bolumlerde ise Spirolina, Pfendericonus ve miliolidlerin bol oldugu belirlenmistir. Priyaboniyen’de ise (SBZ 19-20), Spirolina, Pfendericonus ve miliolidler bol olarak gorulmektedir. Tum bu veriler isiginda, deniz seviyesinin Lutesiyen’den, Priyaboniyen’e kadar dustugu yani ortamin siglastigi, Priyaboniyen’de ise cok sig denizel bir ortamin varligi belirlenmistir. Abstract    This study was carried out to define the benthic foraminifera fauna of Eocene aged Darende Formation which well exposed west of Malatya province between Akcadag and Darende towns. In this manner, seven stratigraphic sections were measured from the Asartepe and Yenice members which are the marine units of Darende Formation. In this study oriented thin sections from hard rock and grain samples of stratigraphic sections were studied to identify benthic foraminifera. According to the defined benthic foraminifera associations the benthic foraminifera zones of SBZ 16, SBZ 17, SBZ 18, SBZ 19-20 corresponding to Lutetian- Bartonian were derived and these zones were correlated with the similar studies.In this study, 55 benthic foraminifera species of 26 genus were defined. One of the genus (Praecalcarina tohmaensis) and two of the species (N. sireli, N.acari) of Nummulites genus are new.3 of the Nummulites species and 5 of the Alveolina species were defined with open nomenclature.Taking care of the benthic foraminifera associations defined in measured stratigraphic sections some environmental interpretations were done. In stratigraphic sections it is observed that Late Lutetian (SBZ 16) units are rich in Nummulites, Assilina and Discocyclina,  Barthonian (SBZ 17-18) units are rich in Alveolina and Nummulites. Toward the top of the stratigraphic sections Alveolina and at the top most of the sections Spirolina, Pfendericonus and miliolide were observed. On the other hand, Priabonian (SBZ 19-20) is rich in Spirolina, Pfendericonus and miliolides. In the light of these data, it is concluded that from Lutetian to Priabonian the sea level has got lower that is the environment has got shallow and during Priabonian there was a shallow marinal environment.