Biostratigraphy of the Gurpi Formation in the Assaluyeh stratigraphic section based on calcareous nannofossils and its comparison with Kuh-e Harm and Pazanan sections (Fars Province)

Document Type : Original Article

Author

• Saeedeh Senemari

Associate Professor, Department of mining, Faculty of Engineering, Imam Khomeini International University (IKIU), Qazvin, Iran

10.22067/sed.facies.2022.46827

Abstract

In this study, biostratigraphy of Gurpi Formation in Assaluyeh section was performed based on the scattering pattern of calcareous nannofossils and a comparison was made with the stratigraphic sections of Kuh-e Harm and Pazanan. In the Harm section, the Gurpi Formation with a thickness of 153 m is mainly consists of marl and intercalations of clay limestone, in the Assaluyeh section with a thickness of 76 m consists of marl, shale and argillaceous limestone, as well as in the Pazanan section with 55 m thickness mainly consists of marl. As a result, ten bio-zones of calcareous nannofossils Lucianorhabdus cayeuxii Zone (CC16‌/‌UC12), Calculites obscurus Zone (CC17/ UC13), Aspidolithus parcus Zone (CC18/‌UC14TP), Calculites ovalis Zone (CC19), Ceratolithoides aculeus Zone (CC20/-UC15bTP), Quadrum sissinghii Zone (CC21/‌UC15cTP), ‌Quadrum trifidum Zone (CC22/‌UC15dTP-UC15eTP), Tranolithus phacelosus Zone (CC23/‌UC15eTP-UC16-UC17), ‌Reinhardtites levis Zone (CC24/UC18), Arkhangelskiella cymbiformis Zone (CC25/UC19-‌UC20a,bTP) of Sissingh (1977) and Burnett (1998) zonations were detected. Based on the identified bio-zones, the age of Gurpi Formation is proposed in Assaluyeh section from late Santonian to early late Maastrichtian, as well as at the Kuh-e Harm and Pazanan is early Campanian to early late Maastrichtian. Also, because the absence of CC26, the Gurpi and Pabdeh Formation boundaries are fossil discontinuous in all three sections.

Keywords

• Biozone
• Calcareous nannofossils
• Fars
• Kuh-e Harm
• Kuh-e Assaluyeh
• Pazanan

Main Subjects

• Systematic Paleontology & Biostratigraphy

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