TITLE:
Late Cretaceous Biostratigraphy Planktonic Foraminifera of the Farokhi Formation, Iran
AUTHORS:
Mohsen Allameh, Reihane Rezayi Yazdi Nejad
KEYWORDS:
Central Iran, Farokhi Formation, Biostratigraphy, Planktonic Foraminifera
JOURNAL NAME:
Open Journal of Geology,
Vol.7 No.3,
March
24,
2017
ABSTRACT: The Farokhi Formation is one of the
informal Central Iran formations, which is located in the NW Tabas township. The Tabas area is a part of
the Central Iran sedimentary basin which is located in the Yazd Province. The Farokhi stratigraphic section is located 7 km northwest from Farokhi village (33°54' 9''N and 54°52'48''E). The Bazyab, Debarso, Haftoman and Choopanan formations are
well-exposed in the studied area. In this study, the Farokhi Formation is investigated in the Farokhi stratigraphic section with regard to
planktonic foraminifera. The Farokhi Formation is mainly composed of thick-bedded limestones with ammonoids, thin-bedded limestone with silicified
echinoids and ichnofossils, marls with nodular cherts, spherical corals and bivalves. Biostratigraphy of the Farokhi Formation
at type section has been concentrated in view
of planktonic foraminifera. Thickness of this formation is 251 meters. The
lower and upper contacts of studied formation with Haftoman and Choopanan
formations are respectively conform and inconsistent. In view of late research, it has been identified that 28 planktonic foraminifera species have a place with 9 genera in edge of
6 biozones, for example: 1) Globotruncanita elevata Partial Range Zone. 2) Globotruncana ventricosa Interval Zone. 3) Globotruncanita stuartiformis Partial Range Zone. 4) Globotruncana aegyptiaca Interval Zone. 5) Gansserina gansseri Interval Zone. 6) Contu-sotruncana contusa Interval Zone. Finally based on this research, Early Campanian-Late Maastrichtian ages for the Farokhi Formation at
type locality have been determined.