Late Cretaceous Biostratigraphy Planktonic Foraminifera of the Farokhi Formation, Iran

• 作者: Mohsen Allameh Reihane Rezayi Yazdi Nejad
• 来源期刊: 地质学期刊(英文)
• 学科: 医学
• 关键词: CENTRAL Iran Farokhi FORMATION BIOSTRATIGRAPHY PLANKTONIC FORAMINIFERA
• 年，卷（期）: dzxqkyw_2017,（3）
• 页码范围: 320-334
• 页数: 15页
• 分类号: R73

摘要

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.